--- /dev/null
+[submodule "libopencm3"]
+ path = libopencm3
+ url = git://github.com/libopencm3/libopencm3.git
--- /dev/null
+ifneq ($(V), 1)
+MFLAGS += --no-print-dir
+Q := @
+endif
+
+all:
+ $(Q)if [ ! -f libopencm3/Makefile ]; then \
+ echo "Initialising git submodules..." ;\
+ git submodule init ;\
+ git submodule update ;\
+ fi
+ $(Q)$(MAKE) $(MFLAGS) -C libopencm3 lib
+ $(Q)$(MAKE) $(MFLAGS) -C src
+
+clean:
+ $(Q)$(MAKE) $(MFLAGS) -C libopencm3 $@
+ $(Q)$(MAKE) $(MFLAGS) -C src $@
+
--- /dev/null
+Subproject commit 5617ed466444790b787b6df8d7f21d1611905fd1
--- /dev/null
+ifneq ($(V), 1)
+MAKEFLAGS += --no-print-dir
+Q := @
+endif
+
+OPT_FLAGS ?= -O2
+
+CFLAGS += -Wall -Wextra -Werror -Wno-char-subscripts\
+ $(OPT_FLAGS) -std=gnu99 -g3 -MD \
+ -I.
+LDFLAGS += $(OPT_FLAGS)
+
+SRC = \
+ timer.c \
+ usb_cdcacm.c \
+
+CROSS_COMPILE ?= arm-none-eabi-
+CC = $(CROSS_COMPILE)gcc
+OBJCOPY = $(CROSS_COMPILE)objcopy
+
+OPT_FLAGS = -Os
+CFLAGS += -mcpu=cortex-m3 -mthumb \
+ -DSTM32F1 -DDISCOVERY_STLINK -I../libopencm3/include \
+ -I .
+LDFLAGS_BOOT := $(LDFLAGS) --specs=nano.specs \
+ -lopencm3_stm32f1 -Wl,--defsym,_stack=0x20005000 \
+ -Wl,-T,bluepill.ld -nostartfiles -lc \
+ -Wl,-Map=mapfile -mthumb -mcpu=cortex-m3 -Wl,-gc-sections \
+ -L../libopencm3/lib
+LDFLAGS = $(LDFLAGS_BOOT)
+
+LDFLAGS += --specs=nosys.specs
+
+all: timer.bin
+
+host_clean:
+ -$(Q)$(RM) timer.bin
+
+OBJ = $(SRC:.c=.o)
+
+timer.elf: $(OBJ)
+ @echo " LD $@"
+ $(Q)$(CC) -o $@ $(OBJ) $(LDFLAGS)
+
+%.o: %.c
+ @echo " CC $<"
+ $(Q)$(CC) $(CFLAGS) -c $< -o $@
+
+%.bin: %.elf
+ @echo " OBJCOPY $@"
+ $(Q)$(OBJCOPY) -O binary $^ $@
+
+%.hex: %
+ @echo " OBJCOPY $@"
+ $(Q)$(OBJCOPY) -O ihex $^ $@
+
+.PHONY: clean host_clean FORCE
+
+clean: host_clean
+ $(Q)echo " CLEAN"
+ -$(Q)$(RM) -f *.o *.d *~ *.elf *.bin $(HOSTFILES)
+ -$(Q)$(RM) -f mapfile
+
--- /dev/null
+/*
+ * This file is part of the libopenstm32 project.
+ *
+ * Copyright (C) 2010 Thomas Otto <tommi@viadmin.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/* Include the common ld script from libopenstm32. */
+INCLUDE stm32/f1/stm32f103x8.ld
+INCLUDE cortex-m-generic.ld
--- /dev/null
+/* This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+/** global definitions and methods (code)
+ * @file global.c
+ * @author King Kévin <kingkevin@cuvoodoo.info>
+ * @date 2016
+ */
+/* standard libraries */
+#include <stdint.h> // standard integer types
+#include <stdlib.h> // general utilities
+
+/* STM32 (including CM3) libraries */
+#include <libopencm3/stm32/rcc.h> // real-time control clock library
+#include <libopencm3/stm32/gpio.h> // general purpose input output library
+#include <libopencm3/stm32/timer.h> // timer library
+#include <libopencm3/cm3/nvic.h> // interrupt handler
+#include <libopencm3/stm32/exti.h> // external interrupt defines
+
+#include "global.h" // common methods
+#include "string.h" // memory utilities
+
+volatile bool button_flag = false;
+
+char* b2s(uint64_t binary, uint8_t rjust)
+{
+ static char string[64+1] = {0}; // the string representation to return
+ uint8_t bit = LENGTH(string)-1; // the index of the bit to print
+ string[bit--] = '\0'; // terminate string
+
+ while (binary) {
+ if (binary & 1) {
+ string[bit--] = '1';
+ } else {
+ string[bit--] = '0';
+ }
+ binary >>= 1;
+ }
+
+ while (64-bit-1<rjust && bit>0) {
+ string[bit--] = '0';
+ }
+
+ return string;
+}
+
+/** switch on board LED */
+void led_on(void)
+{
+#if defined(SYSTEM_BOARD) || defined(BLUE_PILL) || defined(CORE_BOARD)
+ gpio_clear(GPIO(LED_PORT), GPIO(LED_PIN));
+#elif defined(MAPLE_MINI)
+ gpio_set(GPIO(LED_PORT), GPIO(LED_PIN));
+#endif
+}
+/** switch off board LED */
+void led_off(void)
+{
+#if defined(SYSTEM_BOARD) || defined(BLUE_PILL) || defined(CORE_BOARD)
+ gpio_set(GPIO(LED_PORT), GPIO(LED_PIN));
+#elif defined(MAPLE_MINI)
+ gpio_clear(GPIO(LED_PORT), GPIO(LED_PIN));
+#endif
+}
+/** toggle board LED */
+void led_toggle(void)
+{
+ gpio_toggle(GPIO(LED_PORT), GPIO(LED_PIN));
+}
+
+void board_setup(void)
+{
+ // setup LED
+ rcc_periph_clock_enable(RCC_GPIO(LED_PORT)); // enable clock for LED
+ gpio_set_mode(GPIO(LED_PORT), GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO(LED_PIN)); // set LED pin to 'output push-pull'
+ led_off(); // switch off LED per default
+
+ // setup button
+#if defined(BUTTON_PORT) && defined(BUTTON_PIN)
+ rcc_periph_clock_enable(RCC_GPIO(BUTTON_PORT)); // enable clock for button
+ gpio_set_mode(GPIO(BUTTON_PORT), GPIO_MODE_INPUT, GPIO_CNF_INPUT_PULL_UPDOWN, GPIO(BUTTON_PIN)); // set button pin to input
+ rcc_periph_clock_enable(RCC_AFIO); // enable alternate function clock for external interrupt
+ exti_select_source(EXTI(BUTTON_PIN), GPIO(BUTTON_PORT)); // mask external interrupt of this pin only for this port
+#if defined(MAPLE_MINI)
+ gpio_clear(GPIO(BUTTON_PORT), GPIO(BUTTON_PIN)); // pull down to be able to detect button push (go high)
+ exti_set_trigger(EXTI(BUTTON_PIN), EXTI_TRIGGER_RISING); // trigger when button is pressed
+#elif defined(CORE_BOARD)
+ gpio_set(GPIO(BUTTON_PORT), GPIO(BUTTON_PIN)); // pull up to be able to detect button push (go low)
+ exti_set_trigger(EXTI(BUTTON_PIN), EXTI_TRIGGER_FALLING); // trigger when button is pressed
+#endif
+ exti_enable_request(EXTI(BUTTON_PIN)); // enable external interrupt
+ nvic_enable_irq(NVIC_EXTI_IRQ(BUTTON_PIN)); // enable interrupt
+#endif
+}
+
+#if defined(BUTTON_PIN)
+/** interrupt service routine called when button is pressed */
+void EXTI_ISR(BUTTON_PIN)(void)
+{
+ exti_reset_request(EXTI(BUTTON_PIN)); // reset interrupt
+ button_flag = true; // perform button action
+}
+#endif
--- /dev/null
+/* This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+/** global definitions and methods (API)
+ * @file global.h
+ * @author King Kévin <kingkevin@cuvoodoo.info>
+ * @date 2016
+ */
+#pragma once
+
+/** enable debugging functionalities */
+#define DEBUG false
+
+/** get the length of an array */
+#define LENGTH(x) (sizeof(x) / sizeof((x)[0]))
+/** concatenate 2 arguments */
+#define CAT2(x,y) x##y
+/** concatenate 3 arguments */
+#define CAT3(x,y,z) x##y##z
+/** concatenate 4 arguments */
+#define CAT4(w,x,y,z) w##x##y##z
+
+/** @defgroup reg_macro macros to define values based on other defines values
+ * @note used when the value is calculated or isn't a value
+ * @{
+ */
+/** get GPIO based on GPIO identifier */
+#define GPIO(x) CAT2(GPIO,x)
+/** get RCC for GPIO based on GPIO identifier */
+#define RCC_GPIO(x) CAT2(RCC_GPIO,x)
+/** get TIM based on TIM identifier */
+#define TIM(x) CAT2(TIM,x)
+/** get RCC for timer based on TIM identifier */
+#define RCC_TIM(x) CAT2(RCC_TIM,x)
+/** get NVIC IRQ for timer base on TIM identifier */
+#define NVIC_TIM_IRQ(x) CAT3(NVIC_TIM,x,_IRQ)
+/** get interrupt service routine for timer base on TIM identifier */
+#define TIM_ISR(x) CAT3(tim,x,_isr)
+/** get port based on TIMx_CHy identifier */
+#define TIM_CH_PORT(x,y) CAT4(GPIO_BANK_TIM,x,_CH,y)
+/** get pin based on TIMx_CHy identifier */
+#define TIM_CH_PIN(x,y) CAT4(GPIO_TIM,x,_CH,y)
+/** get RCC for port based on TIMx_CHy identifier */
+#define RCC_TIM_CH(x,y) CAT4(RCC_TIM,x,_CH,y)
+#define RCC_TIM1_CH1 RCC_GPIOA /**< RCC for port for on TIM1_CH1 */
+#define RCC_TIM1_CH2 RCC_GPIOA /**< RCC for port for on TIM1_CH2 */
+#define RCC_TIM1_CH3 RCC_GPIOA /**< RCC for port for on TIM1_CH3 */
+#define RCC_TIM1_CH4 RCC_GPIOA /**< RCC for port for on TIM1_CH4 */
+#define RCC_TIM1_CH1N RCC_GPIOB /**< RCC for port for on TIM1_CH1N */
+#define RCC_TIM1_CH2N RCC_GPIOB /**< RCC for port for on TIM1_CH2N */
+#define RCC_TIM1_CH3N RCC_GPIOB /**< RCC for port for on TIM1_CH3N */
+#define RCC_TIM2_CH1_ETR RCC_GPIOA /**< RCC for port for on TIM2_CH1_ETR */
+#define RCC_TIM2_CH2 RCC_GPIOA /**< RCC for port for on TIM2_CH2 */
+#define RCC_TIM2_CH3 RCC_GPIOA /**< RCC for port for on TIM2_CH3 */
+#define RCC_TIM2_CH4 RCC_GPIOA /**< RCC for port for on TIM2_CH4 */
+#define RCC_TIM3_CH1 RCC_GPIOA /**< RCC for port for on TIM3_CH1 */
+#define RCC_TIM3_CH2 RCC_GPIOA /**< RCC for port for on TIM3_CH2 */
+#define RCC_TIM3_CH3 RCC_GPIOB /**< RCC for port for on TIM3_CH3 */
+#define RCC_TIM3_CH4 RCC_GPIOB /**< RCC for port for on TIM3_CH4 */
+#define RCC_TIM4_CH1 RCC_GPIOB /**< RCC for port for on TIM4_CH1 */
+#define RCC_TIM4_CH2 RCC_GPIOB /**< RCC for port for on TIM4_CH2 */
+#define RCC_TIM4_CH3 RCC_GPIOB /**< RCC for port for on TIM4_CH3 */
+#define RCC_TIM4_CH4 RCC_GPIOB /**< RCC for port for on TIM4_CH4 */
+#define RCC_TIM5_CH1 RCC_GPIOA /**< RCC for port for on TIM5_CH1 */
+#define RCC_TIM5_CH2 RCC_GPIOA /**< RCC for port for on TIM5_CH2 */
+#define RCC_TIM5_CH3 RCC_GPIOA /**< RCC for port for on TIM5_CH3 */
+#define RCC_TIM5_CH4 RCC_GPIOA /**< RCC for port for on TIM5_CH4 */
+/** get TIM_IC based on CHx identifier */
+#define TIM_IC(x) CAT2(TIM_IC,x)
+/** get TIM_IC_IN_TI based on CHx identifier */
+#define TIM_IC_IN_TI(x) CAT2(TIM_IC_IN_TI,x)
+/** get TIM_SR_CCxIF based on CHx identifier */
+#define TIM_SR_CCIF(x) CAT3(TIM_SR_CC,x,IF)
+/** get TIM_DIER_CCxIE based on CHx identifier */
+#define TIM_DIER_CCIE(x) CAT3(TIM_DIER_CC,x,IE)
+/** get TIM_CCRy register based on TIMx_CHy identifier */
+#define TIM_CCR(x,y) CAT2(TIM_CCR,y)(TIM(x))
+/** get external interrupt based on pin identifier */
+#define EXTI(x) CAT2(EXTI,x)
+/** get NVIC IRQ for external interrupt base on external interrupt/pin */
+#define NVIC_EXTI_IRQ(x) CAT3(NVIC_EXTI,x,_IRQ)
+#define NVIC_EXTI5_IRQ NVIC_EXTI9_5_IRQ /**< IRQ for line 9 to 5 for pin 5 */
+#define NVIC_EXTI6_IRQ NVIC_EXTI9_5_IRQ /**< IRQ for line 9 to 5 for pin 6 */
+#define NVIC_EXTI7_IRQ NVIC_EXTI9_5_IRQ /**< IRQ for line 9 to 5 for pin 7 */
+#define NVIC_EXTI8_IRQ NVIC_EXTI9_5_IRQ /**< IRQ for line 9 to 5 for pin 8 */
+#define NVIC_EXTI9_IRQ NVIC_EXTI9_5_IRQ /**< IRQ for line 9 to 5 for pin 9 */
+#define NVIC_EXTI10_IRQ NVIC_EXTI15_10_IRQ /**< IRQ for line 15 to 10 for pin 10 */
+#define NVIC_EXTI11_IRQ NVIC_EXTI15_10_IRQ /**< IRQ for line 15 to 10 for pin 11 */
+#define NVIC_EXTI12_IRQ NVIC_EXTI15_10_IRQ /**< IRQ for line 15 to 10 for pin 12 */
+#define NVIC_EXTI13_IRQ NVIC_EXTI15_10_IRQ /**< IRQ for line 15 to 10 for pin 13 */
+#define NVIC_EXTI14_IRQ NVIC_EXTI15_10_IRQ /**< IRQ for line 15 to 10 for pin 14 */
+#define NVIC_EXTI15_IRQ NVIC_EXTI15_10_IRQ /**< IRQ for line 15 to 10 for pin 15 */
+/** get interrupt service routine for timer base on external interrupt/pin */
+#define EXTI_ISR(x) CAT3(exti,x,_isr)
+#define exti5_isr exti9_5_isr /**< isr for line 9 to 5 for pin 5 */
+#define exti6_isr exti9_5_isr /**< isr for line 9 to 5 for pin 6 */
+#define exti7_isr exti9_5_isr /**< isr for line 9 to 5 for pin 7 */
+#define exti8_isr exti9_5_isr /**< isr for line 9 to 5 for pin 8 */
+#define exti9_isr exti9_5_isr /**< isr for line 9 to 5 for pin 9 */
+#define exti10_isr exti15_10_isr /**< isr for line 15 to 10 for pin 10 */
+#define exti11_isr exti15_10_isr /**< isr for line 15 to 10 for pin 11 */
+#define exti12_isr exti15_10_isr /**< isr for line 15 to 10 for pin 12 */
+#define exti13_isr exti15_10_isr /**< isr for line 15 to 10 for pin 13 */
+#define exti14_isr exti15_10_isr /**< isr for line 15 to 10 for pin 14 */
+#define exti15_isr exti15_10_isr /**< isr for line 15 to 10 for pin 15 */
+/** get USART based on USART identifier */
+#define USART(x) CAT2(USART,x)
+/** get RCC for USART based on USART identifier */
+#define USART_RCC(x) CAT2(RCC_USART,x)
+/** get NVIC IRQ for USART based on USART identifier */
+#define USART_IRQ(x) CAT3(NVIC_USART,x,_IRQ)
+/** get interrupt service routine for USART based on USART identifier */
+#define USART_ISR(x) CAT3(usart,x,_isr)
+/** get port for USART based on USART identifier */
+#define USART_PORT(x) CAT2(USART_PORT,x)
+#define USART_PORT1 GPIOA /**< USART 1 is on port A */
+#define USART_PORT2 GPIOA /**< USART 2 is on port A */
+#define USART_PORT3 GPIOB /**< USART 3 is on port B */
+/** get RCC for USART port based on USART identifier */
+#define USART_PORT_RCC(x) CAT2(RCC_USART_PORT,x)
+#define RCC_USART_PORT1 RCC_GPIOA /**< USART 1 is on port A */
+#define RCC_USART_PORT2 RCC_GPIOA /**< USART 2 is on port A */
+#define RCC_USART_PORT3 RCC_GPIOB /**< USART 3 is on port B */
+/** get transmit pin for USART based on USART identifier */
+#define USART_PIN_TX(x) CAT3(GPIO_USART,x,_TX)
+/** get receive pin for USART based on USART identifier */
+#define USART_PIN_RX(x) CAT3(GPIO_USART,x,_RX)
+/** get port based on ADC12_IN identifier */
+#define ADC12_IN_PORT(x) CAT3(ADC12_IN,x,_PORT)
+#define ADC12_IN0_PORT GPIOA /**< ADC12_IN0 is on PA0 */
+#define ADC12_IN1_PORT GPIOA /**< ADC12_IN1 is on PA1 */
+#define ADC12_IN2_PORT GPIOA /**< ADC12_IN2 is on PA2 */
+#define ADC12_IN3_PORT GPIOA /**< ADC12_IN3 is on PA3 */
+#define ADC12_IN4_PORT GPIOA /**< ADC12_IN4 is on PA4 */
+#define ADC12_IN5_PORT GPIOA /**< ADC12_IN5 is on PA5 */
+#define ADC12_IN6_PORT GPIOA /**< ADC12_IN6 is on PA6 */
+#define ADC12_IN7_PORT GPIOA /**< ADC12_IN7 is on PA7 */
+#define ADC12_IN8_PORT GPIOB /**< ADC12_IN8 is on PB0 */
+#define ADC12_IN9_PORT GPIOB /**< ADC12_IN9 is on PB1 */
+#define ADC12_IN10_PORT GPIOC /**< ADC12_IN10 is on PC0 */
+#define ADC12_IN11_PORT GPIOC /**< ADC12_IN11 is on PC1 */
+#define ADC12_IN12_PORT GPIOC /**< ADC12_IN12 is on PC2 */
+#define ADC12_IN13_PORT GPIOC /**< ADC12_IN13 is on PC3 */
+#define ADC12_IN14_PORT GPIOC /**< ADC12_IN14 is on PC4 */
+#define ADC12_IN15_PORT GPIOC /**< ADC12_IN15 is on PC5 */
+/** get pin based on ADC12_IN identifier */
+#define ADC12_IN_PIN(x) CAT3(ADC12_IN,x,_PIN)
+#define ADC12_IN0_PIN GPIO0 /**< ADC12_IN0 is on PA0 */
+#define ADC12_IN1_PIN GPIO1 /**< ADC12_IN1 is on PA1 */
+#define ADC12_IN2_PIN GPIO2 /**< ADC12_IN2 is on PA2 */
+#define ADC12_IN3_PIN GPIO3 /**< ADC12_IN3 is on PA3 */
+#define ADC12_IN4_PIN GPIO4 /**< ADC12_IN4 is on PA4 */
+#define ADC12_IN5_PIN GPIO5 /**< ADC12_IN5 is on PA5 */
+#define ADC12_IN6_PIN GPIO6 /**< ADC12_IN6 is on PA6 */
+#define ADC12_IN7_PIN GPIO7 /**< ADC12_IN7 is on PA7 */
+#define ADC12_IN8_PIN GPIO0 /**< ADC12_IN8 is on PB0 */
+#define ADC12_IN9_PIN GPIO1 /**< ADC12_IN9 is on PB1 */
+#define ADC12_IN10_PIN GPIO0 /**< ADC12_IN10 is on PC0 */
+#define ADC12_IN11_PIN GPIO1 /**< ADC12_IN11 is on PC1 */
+#define ADC12_IN12_PIN GPIO2 /**< ADC12_IN12 is on PC2 */
+#define ADC12_IN13_PIN GPIO3 /**< ADC12_IN13 is on PC3 */
+#define ADC12_IN14_PIN GPIO4 /**< ADC12_IN14 is on PC4 */
+#define ADC12_IN15_PIN GPIO5 /**< ADC12_IN15 is on PC5 */
+/** get RCC based on ADC12_IN identifier */
+#define RCC_ADC12_IN(x) CAT2(RCC_ADC12_IN,x)
+#define RCC_ADC12_IN0 RCC_GPIOA /**< ADC12_IN0 is on PA0 */
+#define RCC_ADC12_IN1 RCC_GPIOA /**< ADC12_IN1 is on PA1 */
+#define RCC_ADC12_IN2 RCC_GPIOA /**< ADC12_IN2 is on PA2 */
+#define RCC_ADC12_IN3 RCC_GPIOA /**< ADC12_IN3 is on PA3 */
+#define RCC_ADC12_IN4 RCC_GPIOA /**< ADC12_IN4 is on PA4 */
+#define RCC_ADC12_IN5 RCC_GPIOA /**< ADC12_IN5 is on PA5 */
+#define RCC_ADC12_IN6 RCC_GPIOA /**< ADC12_IN6 is on PA6 */
+#define RCC_ADC12_IN7 RCC_GPIOA /**< ADC12_IN7 is on PA7 */
+#define RCC_ADC12_IN8 RCC_GPIOB /**< ADC12_IN8 is on PB0 */
+#define RCC_ADC12_IN9 RCC_GPIOB /**< ADC12_IN9 is on PB1 */
+#define RCC_ADC12_IN10 RCC_GPIOC /**< ADC12_IN10 is on PC0 */
+#define RCC_ADC12_IN11 RCC_GPIOC /**< ADC12_IN11 is on PC1 */
+#define RCC_ADC12_IN12 RCC_GPIOC /**< ADC12_IN12 is on PC2 */
+#define RCC_ADC12_IN13 RCC_GPIOC /**< ADC12_IN13 is on PC3 */
+#define RCC_ADC12_IN14 RCC_GPIOC /**< ADC12_IN14 is on PC4 */
+#define RCC_ADC12_IN15 RCC_GPIOC /**< ADC12_IN15 is on PC5 */
+/** get channel based on ADC12_IN identifier */
+#define ADC_CHANNEL(x) CAT2(ADC_CHANNEL,x)
+/** get I2C based on I2C identifier */
+#define I2C(x) CAT2(I2C,x)
+/** get RCC for I2C based on I2C identifier */
+#define RCC_I2C(x) CAT2(RCC_I2C,x)
+/** get RCC for GPIO port for SCL based on I2C identifier */
+#define RCC_I2C_SCL_PORT(x) CAT3(RCC_I2C,x,_PORT)
+#define RCC_I2C1_PORT RCC_GPIOB /**< RCC for GPIO port for SCL for I2C1 */
+#define RCC_I2C2_PORT RCC_GPIOB /**< RCC for GPIO port for SCL for I2C2 */
+/** get RCC for GPIO port for SCL based on I2C identifier */
+#define RCC_I2C_SDA_PORT(x) CAT3(RCC_I2C,x,_PORT)
+#define RCC_I2C1_SDA_PORT RCC_GPIOB /**< RCC for GPIO port for SDA for I2C1 */
+#define RCC_I2C2_SDA_PORT RCC_GPIOB /**< RCC for GPIO port for SDA for I2C2 */
+/** get I2C port for SCL pin based on I2C identifier */
+#define I2C_SCL_PORT(x) CAT3(GPIO_BANK_I2C,x,_SCL)
+/** get I2C port for SDA pin based on I2C identifier */
+#define I2C_SDA_PORT(x) CAT3(GPIO_BANK_I2C,x,_SDA)
+/** get I2C pin for SCL pin based on I2C identifier */
+#define I2C_SCL_PIN(x) CAT3(GPIO_I2C,x,_SCL)
+/** get I2C port for SDA pin based on I2C identifier */
+#define I2C_SDA_PIN(x) CAT3(GPIO_I2C,x,_SDA)
+/** get SPI based on SPI identifier */
+#define SPI(x) CAT2(SPI,x)
+/** get RCC for SPI based on SPI identifier */
+#define RCC_SPI(x) CAT2(RCC_SPI,x)
+/** get RCC for GPIO port for SPI NSS signals */
+#define RCC_SPI_NSS_PORT(x) CAT3(RCC_SPI,x,_NSS_PORT)
+#define RCC_SPI1_NSS_PORT RCC_GPIOA /**< RCC for GPIO port for NSS for SPI1 */
+#define RCC_SPI1_RE_NSS_PORT RCC_GPIOA /**< RCC for GPIO port for NSS for SPI1_RE */
+#define RCC_SPI2_NSS_PORT RCC_GPIOB /**< RCC for GPIO port for NSS for SPI2 */
+/** get RCC for GPIO port for SPI SCK signals */
+#define RCC_SPI_SCK_PORT(x) CAT3(RCC_SPI,x,_SCK_PORT)
+#define RCC_SPI1_SCK_PORT RCC_GPIOA /**< RCC for GPIO port for NSS for SPI1 */
+#define RCC_SPI1_RE_SCK_PORT RCC_GPIOB /**< RCC for GPIO port for NSS for SPI1_RE */
+#define RCC_SPI2_SCK_PORT RCC_GPIOB /**< RCC for GPIO port for NSS for SPI2 */
+/** get RCC for GPIO port for SPI MISO signals */
+#define RCC_SPI_MISO_PORT(x) CAT3(RCC_SPI,x,_MISO_PORT)
+#define RCC_SPI1_MISO_PORT RCC_GPIOA /**< RCC for GPIO port for NSS for SPI1 */
+#define RCC_SPI1_RE_MISO_PORT RCC_GPIOB /**< RCC for GPIO port for NSS for SPI1_RE */
+#define RCC_SPI2_MISO_PORT RCC_GPIOB /**< RCC for GPIO port for NSS for SPI2 */
+/** get RCC for GPIO port for SPI MOSI signals */
+#define RCC_SPI_MOSI_PORT(x) CAT3(RCC_SPI,x,_MOSI_PORT)
+#define RCC_SPI1_MOSI_PORT RCC_GPIOA /**< RCC for GPIO port for NSS for SPI1 */
+#define RCC_SPI1_RE_MOSI_PORT RCC_GPIOB /**< RCC for GPIO port for NSS for SPI1_RE */
+#define RCC_SPI2_MOSI_PORT RCC_GPIOB /**< RCC for GPIO port for NSS for SPI2 */
+/** get SPI port for NSS signal based on SPI identifier */
+#define SPI_NSS_PORT(x) CAT3(GPIO_BANK_SPI,x,_NSS)
+/** get SPI port for SCK signal based on SPI identifier */
+#define SPI_SCK_PORT(x) CAT3(GPIO_BANK_SPI,x,_SCK)
+/** get SPI port for MISO signal based on SPI identifier */
+#define SPI_MISO_PORT(x) CAT3(GPIO_BANK_SPI,x,_MISO)
+/** get SPI port for MOSI signal based on SPI identifier */
+#define SPI_MOSI_PORT(x) CAT3(GPIO_BANK_SPI,x,_MOSI)
+/** get SPI pin for NSS signal based on SPI identifier */
+#define SPI_NSS_PIN(x) CAT3(GPIO_SPI,x,_NSS)
+/** get SPI pin for SCK signal based on SPI identifier */
+#define SPI_SCK_PIN(x) CAT3(GPIO_SPI,x,_SCK)
+/** get SPI pin for MISO signal based on SPI identifier */
+#define SPI_MISO_PIN(x) CAT3(GPIO_SPI,x,_MISO)
+/** get SPI pin for MOSI signal based on SPI identifier */
+#define SPI_MOSI_PIN(x) CAT3(GPIO_SPI,x,_MOSI)
+
+/** @} */
+
+/** @defgroup board_led board LED GPIO
+ * @{
+ */
+#if defined(SYSTEM_BOARD) || defined(CORE_BOARD)
+/* on system and core board LED is on pin 11/PA1 */
+#define LED_PORT A /**< GPIO port (port A) */
+#define LED_PIN 1 /**< GPIO pin (pin PA1) */
+#elif defined(BLUE_PILL)
+/* on minimum system LED is on pin 2/PC13 */
+#define LED_PORT C /**< GPIO port (port C on blue pill) */
+#define LED_PIN 13 /**< GPIO pin (pin PC13 on system board) */
+#elif defined (MAPLE_MINI)
+/* on maple mini LED is on pin 19/PB1 */
+#define LED_PORT B /**< GPIO port (port B on maple mini) */
+#define LED_PIN 1 /**< GPIO pin (pin PB1 on maple mini) */
+#endif
+/** @} */
+
+/** @defgroup board_button board user button GPIO
+ * @{
+ */
+#if defined(MAPLE_MINI)
+/* on maple mini user button is on 32/PB8 */
+#define BUTTON_PORT B /**< GPIO port (port B on maple mini) */
+#define BUTTON_PIN 8 /**< GPIO pin (pin PB8 on maple mini) */
+#elif defined(CORE_BOARD)
+/* on core board user button is on PA8 */
+#define BUTTON_PORT A /**< GPIO port (port A) */
+#define BUTTON_PIN 8 /**< GPIO pin (pin PA8) */
+#endif
+/** @} */
+
+extern volatile bool button_flag; /**< flag set when board user button has been pressed/released */
+
+/** get binary representation of a number
+ * @param[in] binary number to represent in binary
+ * @param[in] rjust justify representation with leading zeros
+ * @return string with binary representation of the number
+ */
+char* b2s(uint64_t binary, uint8_t rjust);
+
+/** switch on board LED */
+void led_on(void);
+
+/** switch off board LED */
+void led_off(void);
+
+/** toggle board LED */
+void led_toggle(void);
+
+/** setup board peripherals */
+void board_setup(void);
+
--- /dev/null
+// vim: tabstop=4 softtabstop=4 shiftwidth=4 expandtab
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * Copyright (C) 2010 Gareth McMullin <gareth@blacksphere.co.nz>
+ *
+ * This library is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <libopencm3/stm32/rcc.h>
+#include <libopencm3/stm32/gpio.h>
+#include <libopencm3/cm3/nvic.h>
+#include <libopencm3/cm3/systick.h>
+#include <libopencm3/usb/usbd.h>
+#include <libopencm3/usb/cdc.h>
+
+#include "usb_cdcacm.h"
+
+uint32_t n_millis_total = 0;
+uint32_t n_millis_cur = 0;
+uint8_t n_millis_loops = 0;
+usbd_device *usbd_dev;
+static uint32_t game_time = 14 * 60 * 1000; // 15 minutes of 1ms ticks
+
+void sys_tick_handler(void) {
+ ++n_millis_cur;
+ ++n_millis_total;
+
+ if (n_millis_total >= game_time) {
+ gpio_clear(GPIOC, GPIO13); // turn on LED
+ return;
+ }
+
+ /* calculate remaining seconds to print out on the serial port, only do this every
+ 1000 millis or so */
+ if (n_millis_loops >= 4) {
+ char seconds_remaining[5];
+ sprintf(seconds_remaining, "%d", (int)((game_time - n_millis_total) / 1000));
+ for (int i = 0; i < 4; i++) {
+ cdcacm_putchar(seconds_remaining[i]);
+ }
+ cdcacm_putchar('\r');
+ cdcacm_putchar('\n');
+ }
+
+ if (n_millis_cur >= 250) {
+ gpio_toggle(GPIOC, GPIO13);
+ ++n_millis_loops;
+ n_millis_cur = 0;
+ return;
+ }
+
+ return;
+}
+
+static void clock_setup(void) {
+ /* Run CPU at 72MHz */
+ rcc_clock_setup_in_hse_8mhz_out_72mhz();
+ rcc_periph_clock_enable(RCC_GPIOA);
+ rcc_periph_clock_enable(RCC_GPIOC);
+
+ /* 72MHz / 8 => 9000000 counts per second */
+ systick_set_clocksource(STK_CSR_CLKSOURCE_AHB_DIV8);
+
+ /* 9000000 / 9000 = 1000 overflows per second - every 1ms one interrupt */
+ /* SysTick interrupt every N clock pulses: set reload to N-1 */
+ systick_set_reload(8999); // 1 ms
+ systick_interrupt_enable();
+ systick_counter_enable();
+}
+
+static void gpio_setup(void) {
+ // Built-in LED on blue pill board, PC13
+ gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_2_MHZ,
+ GPIO_CNF_OUTPUT_PUSHPULL, GPIO13);
+ gpio_set(GPIOC, GPIO13);
+
+ // Pull up the USB D+ line for reset
+ gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_2_MHZ,
+ GPIO_CNF_OUTPUT_OPENDRAIN, GPIO12);
+ gpio_clear(GPIOA, GPIO12);
+}
+
+int main(void)
+{
+ clock_setup();
+ gpio_setup();
+ cdcacm_setup();
+
+ gpio_set(GPIOC, GPIO13);
+
+ while (1) {
+ __asm__("nop");
+ }
+
+ return 0;
+}
+
--- /dev/null
+/* This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+/** library for USB CDC ACM communication (code)
+ * @file usb_cdcacm.c
+ * @author King Kévin <kingkevin@cuvoodoo.info>
+ * @date 2016
+ */
+
+/* standard libraries */
+#include <stdint.h> // standard integer types
+#include <stdio.h> // standard I/O facilities
+#include <stdlib.h> // general utilities
+
+/* STM32 (including CM3) libraries */
+#include <libopencm3/stm32/rcc.h> // real-time control clock library
+#include <libopencm3/stm32/gpio.h> // general purpose input output library
+#include <libopencm3/cm3/nvic.h> // interrupt handler
+#include <libopencm3/cm3/scb.h> // reset utilities
+#include <libopencmsis/core_cm3.h> // Cortex M3 utilities
+#include <libopencm3/usb/usbd.h> // USB library
+#include <libopencm3/usb/cdc.h> // USB CDC library
+#include <libopencm3/cm3/sync.h> // synchronisation utilities
+
+#include "global.h"
+#include "usb_cdcacm.h" // USB CDC ACM header and definitions
+
+/** USB CDC ACM device descriptor
+ * @note as defined in USB CDC specification section 5
+ */
+static const struct usb_device_descriptor device_descriptor = {
+ .bLength = USB_DT_DEVICE_SIZE, // the size of this header in bytes, 18
+ .bDescriptorType = USB_DT_DEVICE, // a value of 1 indicates that this is a device descriptor
+ .bcdUSB = 0x0200, // this device supports USB 2.0
+ .bDeviceClass = USB_CLASS_CDC, // use the CDC device class
+ .bDeviceSubClass = 0, // unused
+ .bDeviceProtocol = 0, // unused
+ .bMaxPacketSize0 = 64, // packet size for endpoint zero in bytes
+ .idVendor = 0xc440, // Vendor ID (CuVo...)
+ .idProduct = 0x0d00, // product ID within the Vendor ID space (...odoo)
+ .bcdDevice = 0x0100, // version number for the device
+ .iManufacturer = 1, // the index of the string in the string table that represents the name of the manufacturer of this device.
+ .iProduct = 2, // the index of the string in the string table that represents the name of the product
+ .iSerialNumber = 3, // the index of the string in the string table that represents the serial number of this item in string form.
+ .bNumConfigurations = 1, // the number of possible configurations this device has
+};
+
+/** USB CDC ACM data endpoints
+ * @note as defined in USB CDC specification section 5
+ */
+static const struct usb_endpoint_descriptor data_endpoints[] = {{
+ .bLength = USB_DT_ENDPOINT_SIZE, // the size of the endpoint descriptor in bytes
+ .bDescriptorType = USB_DT_ENDPOINT, // a value of 5 indicates that this describes an endpoint
+ .bEndpointAddress = 0x01, // OUT (from host) direction (0<<7), endpoint 1
+ .bmAttributes = USB_ENDPOINT_ATTR_BULK, // bulk mode
+ .wMaxPacketSize = 64, // maximum packet size
+ .bInterval = 1, // the frequency, in number of frames, that we're going to be sending data
+},{
+ .bLength = USB_DT_ENDPOINT_SIZE, // the size of the endpoint descriptor in bytes
+ .bDescriptorType = USB_DT_ENDPOINT, // a value of 5 indicates that this describes an endpoint
+ .bEndpointAddress = 0x82, // IN (to host) direction (1<<7), endpoint 2
+ .bmAttributes = USB_ENDPOINT_ATTR_BULK, // bulk mode
+ .wMaxPacketSize = 64, // maximum packet size
+ .bInterval = 1, // the frequency, in number of frames, that we're going to be sending data
+}};
+
+/** USB CDC ACM communication endpoints
+ * @note This notification endpoint isn't implemented. According to CDC spec its optional, but its absence causes a NULL pointer dereference in Linux cdc_acm driver
+ */
+static const struct usb_endpoint_descriptor communication_endpoints[] = {{
+ .bLength = USB_DT_ENDPOINT_SIZE, // the size of the endpoint descriptor in bytes
+ .bDescriptorType = USB_DT_ENDPOINT, // a value of 5 indicates that this describes an endpoint
+ .bEndpointAddress = 0x83, // IN (to host) direction (1<<7), endpoint 3
+ .bmAttributes = USB_ENDPOINT_ATTR_INTERRUPT, // interrupt mode
+ .wMaxPacketSize = 16, // maximum packet size
+ .bInterval = 255, // the frequency, in number of frames, that we're going to be sending data
+}};
+
+/** USB CDC ACM functional descriptor
+ * @return
+ * @note as defined in USB CDC specification section 5.2.3
+ */
+static const struct {
+ struct usb_cdc_header_descriptor header; /**< header */
+ struct usb_cdc_call_management_descriptor call_mgmt; /**< call management descriptor */
+ struct usb_cdc_acm_descriptor acm; /**< descriptor */
+ struct usb_cdc_union_descriptor cdc_union; /**< descriptor */
+} __attribute__((packed)) cdcacm_functional_descriptors = {
+ .header = {
+ .bFunctionLength = sizeof(struct usb_cdc_header_descriptor), /**< descriptor length */
+ .bDescriptorType = CS_INTERFACE, /**< descriptor type */
+ .bDescriptorSubtype = USB_CDC_TYPE_HEADER, /**< descriptor subtype */
+ .bcdCDC = 0x0110, /**< CDC value */
+ },
+ .call_mgmt = {
+ .bFunctionLength = sizeof(struct usb_cdc_call_management_descriptor), /**< descriptor length */
+ .bDescriptorType = CS_INTERFACE, /**< descriptor type */
+ .bDescriptorSubtype = USB_CDC_TYPE_CALL_MANAGEMENT, /**< descriptor subtype */
+ .bmCapabilities = 0, /**< capabilities */
+ .bDataInterface = 1, /**< data interface */
+ },
+ .acm = {
+ .bFunctionLength = sizeof(struct usb_cdc_acm_descriptor), /**< descriptor length */
+ .bDescriptorType = CS_INTERFACE, /**< descriptor type */
+ .bDescriptorSubtype = USB_CDC_TYPE_ACM, /**< descriptor subtype */
+ .bmCapabilities = 0, /**< capabilities */
+ },
+ .cdc_union = {
+ .bFunctionLength = sizeof(struct usb_cdc_union_descriptor), /**< descriptor length */
+ .bDescriptorType = CS_INTERFACE, /**< descriptor type */
+ .bDescriptorSubtype = USB_CDC_TYPE_UNION, /**< descriptor subtype */
+ .bControlInterface = 0, /**< control interface */
+ .bSubordinateInterface0 = 1, /**< subordinate interface */
+ },
+};
+
+/** USB CDC interface descriptor
+ * @note as defined in USB CDC specification section 5.1.3
+ */
+static const struct usb_interface_descriptor communication_interface[] = {{
+ .bLength = USB_DT_INTERFACE_SIZE,
+ .bDescriptorType = USB_DT_INTERFACE,
+ .bInterfaceNumber = 0,
+ .bAlternateSetting = 0,
+ .bNumEndpoints = 1,
+ .bInterfaceClass = USB_CLASS_CDC,
+ .bInterfaceSubClass = USB_CDC_SUBCLASS_ACM,
+ .bInterfaceProtocol = USB_CDC_PROTOCOL_NONE,
+ .iInterface = 0,
+
+ .endpoint = communication_endpoints,
+
+ .extra = &cdcacm_functional_descriptors,
+ .extralen = sizeof(cdcacm_functional_descriptors),
+}};
+
+/** USB CDC ACM data class interface descriptor
+ * @note as defined in USB CDC specification section 5.1.3
+ */
+static const struct usb_interface_descriptor data_interface[] = {{
+ .bLength = USB_DT_INTERFACE_SIZE,
+ .bDescriptorType = USB_DT_INTERFACE,
+ .bInterfaceNumber = 1,
+ .bAlternateSetting = 0,
+ .bNumEndpoints = 2,
+ .bInterfaceClass = USB_CLASS_DATA,
+ .bInterfaceSubClass = 0,
+ .bInterfaceProtocol = 0,
+ .iInterface = 0,
+
+ .endpoint = data_endpoints,
+}};
+
+/** USB CDC ACM interface descriptor */
+static const struct usb_interface interfaces[] = {{
+ .num_altsetting = 1,
+ .altsetting = communication_interface,
+}, {
+ .num_altsetting = 1,
+ .altsetting = data_interface,
+}};
+
+/** USB CDC ACM configuration descriptor */
+static const struct usb_config_descriptor config = {
+ .bLength = USB_DT_CONFIGURATION_SIZE, // the length of this header in bytes
+ .bDescriptorType = USB_DT_CONFIGURATION, // a value of 2 indicates that this is a configuration descriptor
+ .wTotalLength = 0, // this should hold the total size of the configuration descriptor including all sub interfaces. it is automatically filled in by the USB stack in libopencm3
+ .bNumInterfaces = 2, // the number of interfaces in this configuration
+ .bConfigurationValue = 1, // the index of this configuration
+ .iConfiguration = 0, // a string index describing this configuration (zero means not provided)
+ .bmAttributes = 0x80, // self powered (0<<6), supports remote wakeup (0<<5)
+ .bMaxPower = 0x32, // the maximum amount of current that this device will draw in 2mA units
+ // end of header
+ .interface = interfaces, // pointer to an array of interfaces
+};
+
+/** USB string table
+ * @note starting with index 1
+ */
+static const char *usb_strings[] = {
+ "BarBillards v1",
+ "CDC-ACM",
+ "STM32F1",
+};
+
+static uint8_t usbd_control_buffer[128] = {0}; /**< buffer to be used for control requests */
+static usbd_device *usb_device = NULL; /**< structure holding all the info related to the USB device */
+static bool connected = false; /**< is the USB device is connected to a host */
+
+/* input and output ring buffer, indexes, and available memory */
+static uint8_t rx_buffer[CDCACM_BUFFER] = {0}; /**< ring buffer for received data */
+static volatile uint8_t rx_i = 0; /**< current position of read received data */
+static volatile uint8_t rx_used = 0; /**< how much data has been received and not red */
+mutex_t rx_lock = MUTEX_UNLOCKED; /**< lock to update rx_i or rx_used */
+static uint8_t tx_buffer[CDCACM_BUFFER] = {0}; /**< ring buffer for data to transmit */
+static volatile uint8_t tx_i = 0; /**< current position if transmitted data */
+static volatile uint8_t tx_used = 0; /**< how much data needs to be transmitted */
+mutex_t tx_lock = MUTEX_UNLOCKED; /**< lock to update tx_i or tx_used */
+volatile uint8_t cdcacm_received = 0; // same as rx_used, but since the user can write this variable we don't rely on it
+
+/** disconnect USB by pulling down D+ to for re-enumerate */
+static void usb_disconnect(void)
+{
+ /* short USB disconnect to force re-enumerate */
+#if defined(SYSTEM_BOARD) || defined(BLUE_PILL)
+ // pull USB D+ low for a short while
+ rcc_periph_clock_enable(RCC_GPIOA);
+ gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO12);
+ gpio_clear(GPIOA, GPIO12);
+ for (uint32_t i = 0; i < 0x2000; i++) {
+ __asm__("nop");
+ }
+#elif defined(MAPLE_MINI)
+ // disconnect USB D+ using dedicated DISC line/circuit on PB9
+ rcc_periph_clock_enable(RCC_GPIOB);
+ gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO9);
+ gpio_set(GPIOB, GPIO9);
+ for (uint32_t i = 0; i < 0x2000; i++) {
+ __asm__("nop");
+ }
+ gpio_clear(GPIOB, GPIO9);
+#endif
+}
+
+/** incoming USB CDC ACM control request
+ * @param[in] usbd_dev USB device descriptor
+ * @param[in] req control request information
+ * @param[in] buf control request data
+ * @param[in] len control request data length
+ * @param[in] complete not used
+ * @return 0 if succeeded, error else
+ * @note resets device when configured with 5 bits
+ */
+static enum usbd_request_return_codes cdcacm_control_request(usbd_device *usbd_dev, struct usb_setup_data *req, uint8_t **buf, uint16_t *len, void (**complete)(usbd_device *usbd_dev, struct usb_setup_data *req))
+{
+ (void)complete;
+ (void)buf;
+ (void)usbd_dev;
+
+ switch (req->bRequest) {
+ case USB_CDC_REQ_SET_CONTROL_LINE_STATE:
+ connected = req->wValue ? true : false; // check if terminal is open
+ //bool dtr = (req->wValue & (1 << 0)) ? true : false;
+ //bool rts = (req->wValue & (1 << 1)) ? true : false;
+ /* this Linux cdc_acm driver requires this to be implemented
+ * even though it's optional in the CDC spec, and we don't
+ * advertise it in the ACM functional descriptor.
+ */
+ uint8_t reply[10] = {0};
+ struct usb_cdc_notification *notif = (void *)reply;
+ /* we echo signals back to host as notification. */
+ notif->bmRequestType = 0xA1;
+ notif->bNotification = USB_CDC_NOTIFY_SERIAL_STATE;
+ notif->wValue = 0;
+ notif->wIndex = 0;
+ notif->wLength = 2;
+ reply[8] = req->wValue & 3;
+ reply[9] = 0;
+ usbd_ep_write_packet(usbd_dev, 0x83, reply, LENGTH(reply));
+ return USBD_REQ_HANDLED;
+ break;
+ case USB_CDC_REQ_SET_LINE_CODING:
+ // ignore if length is wrong
+ if (*len < sizeof(struct usb_cdc_line_coding)) {
+ return USBD_REQ_NOTSUPP;
+ }
+ // get the line coding
+ struct usb_cdc_line_coding *coding = (struct usb_cdc_line_coding *)*buf;
+ /* reset device is the data bits is set to 5
+ * this is used to allowing rebooting the device in DFU mode for reflashing
+ * to reset the device from the host you can use stty --file /dev/ttyACM0 115200 raw cs5
+ */
+ if (coding->bDataBits==5) {
+ usb_disconnect(); // force re-enumerate after reset
+ scb_reset_system(); // reset device
+ while (true); // wait for the reset to happen
+ }
+ return USBD_REQ_HANDLED;
+ break;
+ default:
+ return USBD_REQ_HANDLED;
+ }
+ return USBD_REQ_NOTSUPP;
+}
+
+/** USB CDC ACM data received callback
+ * @param[in] usbd_dev USB device descriptor
+ * @param[in] ep endpoint where data came in
+ */
+static void cdcacm_data_rx_cb(usbd_device *usbd_dev, uint8_t ep)
+{
+ (void)ep;
+
+ char usb_data[64] = {0}; // buffer to read data
+ uint16_t usb_length = 0; // length of incoming data
+
+ /* receive data */
+ usb_length = usbd_ep_read_packet(usbd_dev, 0x01, usb_data, sizeof(usb_data));
+ if (usb_length) { // copy received data
+ for (uint16_t i=0; i<usb_length && rx_used<LENGTH(rx_buffer); i++) { // only until buffer is full
+ rx_buffer[(rx_i+rx_used)%LENGTH(rx_buffer)] = usb_data[i]; // put character in buffer
+ rx_used++; // update used buffer
+ }
+ cdcacm_received = rx_used; // update available data
+ }
+}
+
+/** USB CDC ACM data transmitted callback
+ * @param[in] usbd_dev USB device descriptor
+ * @param[in] ep endpoint where data came in
+ */
+static void cdcacm_data_tx_cb(usbd_device *usbd_dev, uint8_t ep)
+{
+ (void)ep;
+ (void)usbd_dev;
+
+ if (!usbd_dev || !connected || !tx_used) { // verify if we can send and there is something to send
+ return;
+ }
+ if (mutex_trylock(&tx_lock)) { // try to get lock
+ uint8_t usb_length = (tx_used > 64 ? 64 : tx_used); // length of data to be transmitted (respect max packet size)
+ usb_length = (usb_length > (LENGTH(tx_buffer)-tx_i) ? LENGTH(tx_buffer)-tx_i : usb_length); // since here we use the source array not as ring buffer, only go up to the end
+ while (usb_length != usbd_ep_write_packet(usb_device, 0x82, (void*)(&tx_buffer[tx_i]), usb_length)); // ensure data is written into transmit buffer
+ tx_i = (tx_i+usb_length)%LENGTH(tx_buffer); // update location on buffer
+ tx_used -= usb_length; // update used size
+ mutex_unlock(&tx_lock); // release lock
+ } else {
+ usbd_ep_write_packet(usb_device, 0x82, NULL, 0); // trigger empty tx for a later callback
+ }
+ usbd_poll(usb_device); // ensure the data gets sent
+}
+
+/** set USB CDC ACM configuration
+ * @param[in] usbd_dev USB device descriptor
+ * @param[in] wValue not used
+ */
+static void cdcacm_set_config(usbd_device *usbd_dev, uint16_t wValue)
+{
+ (void)wValue;
+
+ usbd_ep_setup(usbd_dev, 0x01, USB_ENDPOINT_ATTR_BULK, 64, cdcacm_data_rx_cb);
+ usbd_ep_setup(usbd_dev, 0x82, USB_ENDPOINT_ATTR_BULK, 64, cdcacm_data_tx_cb);
+ usbd_ep_setup(usbd_dev, 0x83, USB_ENDPOINT_ATTR_INTERRUPT, 16, NULL);
+
+ usbd_register_control_callback( usbd_dev, USB_REQ_TYPE_CLASS | USB_REQ_TYPE_INTERFACE, USB_REQ_TYPE_TYPE | USB_REQ_TYPE_RECIPIENT, cdcacm_control_request);
+}
+
+void cdcacm_setup(void)
+{
+ connected = false; // start with USB not connected
+ usb_disconnect(); // force re-enumerate (useful after a restart or if there is a bootloader using another USB profile)
+
+ /* initialize USB */
+ usb_device = usbd_init(&st_usbfs_v1_usb_driver, &device_descriptor, &config, usb_strings, 3, usbd_control_buffer, sizeof(usbd_control_buffer));
+ usbd_register_set_config_callback(usb_device, cdcacm_set_config);
+
+ /* enable interrupts (to not have to poll all the time) */
+ nvic_enable_irq(NVIC_USB_LP_CAN_RX0_IRQ); // without this USB isn't detected by the host
+
+ /* reset buffer states */
+ rx_i = 0;
+ rx_used = 0;
+ mutex_unlock(&rx_lock);
+ cdcacm_received = 0;
+ tx_i = 0;
+ tx_used = 0;
+ mutex_unlock(&tx_lock);
+}
+
+char cdcacm_getchar(void)
+{
+ while (!rx_used) { // idle until data is available
+ __WFI(); // sleep until interrupt (not sure if it's a good idea here)
+ }
+ char to_return = rx_buffer[rx_i]; // get the next available character
+ rx_i = (rx_i+1)%LENGTH(rx_buffer); // update used buffer
+ rx_used--; // update used buffer
+ cdcacm_received = rx_used; // update available data
+ return to_return;
+}
+
+void cdcacm_putchar(char c)
+{
+ if (!usb_device || !connected) {
+ return;
+ }
+ mutex_lock(&tx_lock); // get lock to prevent race condition
+ if (tx_used<LENGTH(tx_buffer)) { // buffer not full
+ tx_buffer[(tx_i+tx_used)%LENGTH(tx_buffer)] = c; // put character in buffer
+ tx_used++; // update used buffer
+ } else { // buffer full (might be that no terminal is connected to this serial)
+ tx_i = (tx_i+1)%LENGTH(tx_buffer); // shift start
+ tx_buffer[(tx_i+tx_used)%LENGTH(tx_buffer)] = c; // overwrite old data
+ }
+ mutex_unlock(&tx_lock); // release lock
+ if (tx_used==1) { // to buffer is not empty anymore
+ usbd_ep_write_packet(usb_device, 0x82, NULL, 0); // trigger tx callback
+ }
+}
+
+/** USB interrupt service routine called when data is received */
+void usb_lp_can_rx0_isr(void) {
+ usbd_poll(usb_device);
+}
--- /dev/null
+/* This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+/** library for USB CDC ACM communication (API)
+ * @file usb_cdcacm.h
+ * @author King Kévin <kingkevin@cuvoodoo.info>
+ * @date 2016
+ */
+#pragma once
+
+/** transmit and receive buffer sizes */
+#define CDCACM_BUFFER 64
+/** how many bytes available in the received buffer since last read */
+extern volatile uint8_t cdcacm_received;
+
+/** setup USB CDC ACM peripheral */
+void cdcacm_setup(void);
+/** get character received over USB (blocking)
+ * @return character received over USB
+ * @note blocks until character is received over USB when received buffer is empty
+ */
+char cdcacm_getchar(void);
+/** send character over USB (non-blocking)
+ * @param[in] c character to send
+ * @note blocks if transmit buffer is full, else puts in buffer and returns
+ */
+void cdcacm_putchar(char c);