timers, pwm, printf

targets/stm32l442/Makefile

@@ -2,7 +2,7 @@ CC=arm-none-eabi-gcc
 CP=arm-none-eabi-objcopy
 SZ=arm-none-eabi-size
 
-SRC=src/main.c src/startup_stm32l432xx.s src/system_stm32l4xx.c $(wildcard lib/*c)
+SRC=src/main.c src/init.c src/redirect.c src/startup_stm32l432xx.s src/system_stm32l4xx.c $(wildcard lib/*c)
 OBJ=$(SRC:.c=.o)
 INC=-Isrc/ -Isrc/cmsis -Ilib/
 LDSCRIPT=stm32l432xx.ld
@@ -18,25 +18,30 @@ HW=-mcpu=cortex-m4 -mfpu=fpv4-sp-d16 -mfloat-abi=hard -mthumb
 CHIP=STM32L442xx
 
 CFLAGS=$(INC) -c -D$(CHIP) -DUSE_FULL_LL_DRIVER -O0  -Wall -fdata-sections -ffunction-sections
-LDFLAGS=$(HW) -specs=nano.specs -T$(LDSCRIPT) -Wl,-Map=$(TARGET).map,--cref -Wl,--gc-sections
+LDFLAGS=$(HW) -specs=nano.specs  -specs=nosys.specs -T$(LDSCRIPT) -Wl,-Map=$(TARGET).map,--cref -Wl,--gc-sections
+
+.PRECIOUS: %.o
 
 all: $(TARGET).elf
 	$(SZ) $^
-	$(CP) -O ihex $^ $(TARGET).hex
 
 %.o: %.c
 	$(CC) $^ $(HW) $(CFLAGS) -o $@
 
+
 %.o: %.s
 	$(CC) $^ $(HW) $(CFLAGS) -o $@
 
 %.elf: $(OBJ)
 	$(CC) $^ $(HW) $(LDFLAGS) -o $@
 
+%.hex: %.elf
+	$(CP) -O ihex $^ $(TARGET).hex
+
 clean:
 	rm -f *.o src/*.o src/*.elf *.elf
 
-flash:
+flash: $(TARGET).hex
 	STM32_Programmer_CLI -c port=SWD -halt -d $(TARGET).hex -rst
 	sleep 0.5
 	python dfuse-tool/dfuse-tool.py --leave

targets/stm32l442/src/app.h

@@ -0,0 +1,11 @@
+#ifndef _APP_H_
+#define _APP_H_
+#include <stdint.h>
+
+#define DEBUG_UART      USART1
+
+extern uint32_t __65_seconds;
+
+#define millis()    (((uint32_t)TIM6->CNT) | (__65_seconds<<16))
+
+#endif

targets/stm32l442/src/init.c

@@ -0,0 +1,301 @@
+
+#include <stdint.h>
+#include "stm32l4xx.h"
+#include "stm32l4xx_ll_gpio.h"
+#include "stm32l4xx_ll_rcc.h"
+#include "stm32l4xx_ll_system.h"
+#include "stm32l4xx_ll_pwr.h"
+#include "stm32l4xx_ll_utils.h"
+#include "stm32l4xx_ll_cortex.h"
+#include "stm32l4xx_ll_gpio.h"
+#include "stm32l4xx_ll_usart.h"
+#include "stm32l4xx_ll_bus.h"
+#include "stm32l4xx_ll_tim.h"
+
+/* USER CODE BEGIN Includes */
+
+/* USER CODE END Includes */
+
+/* Private variables ---------------------------------------------------------*/
+
+/* USER CODE BEGIN PV */
+/* Private variables ---------------------------------------------------------*/
+
+/* USER CODE END PV */
+
+/* Private function prototypes -----------------------------------------------*/
+static void LL_Init(void);
+void SystemClock_Config(void);
+static void MX_GPIO_Init(void);
+static void MX_USART1_UART_Init(void);
+static void MX_TIM2_Init(void);
+static void MX_TIM6_Init(void);
+
+#define Error_Handler() _Error_Handler(__FILE__,__LINE__)
+void _Error_Handler(char *file, int line);
+
+
+void hw_init(void)
+{
+  /* USER CODE BEGIN 1 */
+
+  /* USER CODE END 1 */
+
+  /* MCU Configuration----------------------------------------------------------*/
+
+  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
+  LL_Init();
+
+  /* USER CODE BEGIN Init */
+
+  /* USER CODE END Init */
+
+  /* Configure the system clock */
+  SystemClock_Config();
+
+  /* USER CODE BEGIN SysInit */
+
+  /* USER CODE END SysInit */
+
+  /* Initialize all configured peripherals */
+  MX_GPIO_Init();
+  MX_USART1_UART_Init();
+  MX_TIM2_Init();
+
+  MX_TIM6_Init();
+
+  TIM6->SR = 0;
+  __enable_irq();
+  NVIC_EnableIRQ(TIM6_IRQn);
+
+}
+static void LL_Init(void)
+{
+  
+
+  LL_APB2_GRP1_EnableClock(LL_APB2_GRP1_PERIPH_SYSCFG);
+  LL_APB1_GRP1_EnableClock(LL_APB1_GRP1_PERIPH_PWR);
+
+  NVIC_SetPriorityGrouping(4);
+
+  /* System interrupt init*/
+  /* MemoryManagement_IRQn interrupt configuration */
+  NVIC_SetPriority(MemoryManagement_IRQn, NVIC_EncodePriority(NVIC_GetPriorityGrouping(),0, 0));
+  /* BusFault_IRQn interrupt configuration */
+  NVIC_SetPriority(BusFault_IRQn, NVIC_EncodePriority(NVIC_GetPriorityGrouping(),0, 0));
+  /* UsageFault_IRQn interrupt configuration */
+  NVIC_SetPriority(UsageFault_IRQn, NVIC_EncodePriority(NVIC_GetPriorityGrouping(),0, 0));
+  /* SVCall_IRQn interrupt configuration */
+  NVIC_SetPriority(SVCall_IRQn, NVIC_EncodePriority(NVIC_GetPriorityGrouping(),0, 0));
+  /* DebugMonitor_IRQn interrupt configuration */
+  NVIC_SetPriority(DebugMonitor_IRQn, NVIC_EncodePriority(NVIC_GetPriorityGrouping(),0, 0));
+  /* PendSV_IRQn interrupt configuration */
+  NVIC_SetPriority(PendSV_IRQn, NVIC_EncodePriority(NVIC_GetPriorityGrouping(),0, 0));
+  /* SysTick_IRQn interrupt configuration */
+  NVIC_SetPriority(SysTick_IRQn, NVIC_EncodePriority(NVIC_GetPriorityGrouping(),0, 0));
+
+}
+
+/**
+  * @brief System Clock Configuration
+  * @retval None
+  */
+void SystemClock_Config(void)
+{
+
+  LL_FLASH_SetLatency(LL_FLASH_LATENCY_2);
+
+   if(LL_FLASH_GetLatency() != LL_FLASH_LATENCY_2)
+  {
+  Error_Handler();  
+  }
+  LL_PWR_SetRegulVoltageScaling(LL_PWR_REGU_VOLTAGE_SCALE1);
+
+  LL_RCC_MSI_Enable();
+
+   /* Wait till MSI is ready */
+  while(LL_RCC_MSI_IsReady() != 1)
+  {
+    
+  }
+  LL_RCC_MSI_EnableRangeSelection();
+
+  LL_RCC_MSI_SetRange(LL_RCC_MSIRANGE_11);
+
+  LL_RCC_MSI_SetCalibTrimming(0);
+
+  LL_RCC_SetSysClkSource(LL_RCC_SYS_CLKSOURCE_MSI);
+
+   /* Wait till System clock is ready */
+  while(LL_RCC_GetSysClkSource() != LL_RCC_SYS_CLKSOURCE_STATUS_MSI)
+  {
+  
+  }
+  LL_RCC_SetAHBPrescaler(LL_RCC_SYSCLK_DIV_1);
+
+  LL_RCC_SetAPB1Prescaler(LL_RCC_APB1_DIV_16);
+
+  LL_RCC_SetAPB2Prescaler(LL_RCC_APB2_DIV_16);
+
+  LL_Init1msTick(48000000);
+
+  LL_SYSTICK_SetClkSource(LL_SYSTICK_CLKSOURCE_HCLK);
+
+  LL_SetSystemCoreClock(48000000);
+
+  LL_RCC_SetUSARTClockSource(LL_RCC_USART1_CLKSOURCE_PCLK2);
+
+  /* SysTick_IRQn interrupt configuration */
+  NVIC_SetPriority(SysTick_IRQn, NVIC_EncodePriority(NVIC_GetPriorityGrouping(),0, 0));
+}
+
+/* TIM2 init function */
+static void MX_TIM2_Init(void)
+{
+
+  LL_TIM_InitTypeDef TIM_InitStruct;
+  LL_TIM_OC_InitTypeDef TIM_OC_InitStruct;
+
+  LL_GPIO_InitTypeDef GPIO_InitStruct;
+
+  /* Peripheral clock enable */
+  LL_APB1_GRP1_EnableClock(LL_APB1_GRP1_PERIPH_TIM2);
+
+  TIM2->SR = 0 ;
+
+  TIM_InitStruct.Prescaler = 0;
+  TIM_InitStruct.CounterMode = LL_TIM_COUNTERMODE_UP;
+  TIM_InitStruct.Autoreload = 1000;
+  TIM_InitStruct.ClockDivision = LL_TIM_CLOCKDIVISION_DIV1;
+  LL_TIM_Init(TIM2, &TIM_InitStruct);
+
+  LL_TIM_EnableARRPreload(TIM2);
+
+  LL_TIM_SetClockSource(TIM2, LL_TIM_CLOCKSOURCE_INTERNAL);
+
+  TIM_OC_InitStruct.OCMode = LL_TIM_OCMODE_PWM1;
+  TIM_OC_InitStruct.OCState = LL_TIM_OCSTATE_ENABLE;
+  TIM_OC_InitStruct.OCNState = LL_TIM_OCSTATE_ENABLE;
+  TIM_OC_InitStruct.CompareValue = 1000;
+  TIM_OC_InitStruct.OCPolarity = LL_TIM_OCPOLARITY_HIGH;
+  LL_TIM_OC_Init(TIM2, LL_TIM_CHANNEL_CH2, &TIM_OC_InitStruct);
+
+  LL_TIM_OC_DisableFast(TIM2, LL_TIM_CHANNEL_CH2);
+
+  TIM_OC_InitStruct.OCState = LL_TIM_OCSTATE_ENABLE;
+  TIM_OC_InitStruct.OCNState = LL_TIM_OCSTATE_ENABLE;
+  LL_TIM_OC_Init(TIM2, LL_TIM_CHANNEL_CH3, &TIM_OC_InitStruct);
+
+  LL_TIM_OC_DisableFast(TIM2, LL_TIM_CHANNEL_CH3);
+
+  TIM_OC_InitStruct.OCState = LL_TIM_OCSTATE_ENABLE;
+  TIM_OC_InitStruct.OCNState = LL_TIM_OCSTATE_ENABLE;
+  LL_TIM_OC_Init(TIM2, LL_TIM_CHANNEL_CH4, &TIM_OC_InitStruct);
+
+  LL_TIM_OC_DisableFast(TIM2, LL_TIM_CHANNEL_CH4);
+
+  LL_TIM_SetOCRefClearInputSource(TIM2, LL_TIM_OCREF_CLR_INT_NC);
+
+  LL_TIM_DisableExternalClock(TIM2);
+
+  LL_TIM_ConfigETR(TIM2, LL_TIM_ETR_POLARITY_NONINVERTED, LL_TIM_ETR_PRESCALER_DIV1, LL_TIM_ETR_FILTER_FDIV1);
+
+  LL_TIM_SetTriggerOutput(TIM2, LL_TIM_TRGO_RESET);
+
+  LL_TIM_DisableMasterSlaveMode(TIM2);
+
+  /**TIM2 GPIO Configuration  
+  PA1   ------> TIM2_CH2
+  PA2   ------> TIM2_CH3
+  PA3   ------> TIM2_CH4 
+  */
+  GPIO_InitStruct.Pin = LL_GPIO_PIN_1|LL_GPIO_PIN_2|LL_GPIO_PIN_3;
+  GPIO_InitStruct.Mode = LL_GPIO_MODE_ALTERNATE;
+  GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_LOW;
+  GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
+  GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
+  GPIO_InitStruct.Alternate = LL_GPIO_AF_1;
+  LL_GPIO_Init(GPIOA, &GPIO_InitStruct);
+
+  LL_TIM_EnableCounter(TIM2);
+
+}
+
+/* USART1 init function */
+static void MX_USART1_UART_Init(void)
+{
+
+  LL_USART_InitTypeDef USART_InitStruct;
+
+  LL_GPIO_InitTypeDef GPIO_InitStruct;
+
+  /* Peripheral clock enable */
+  LL_APB2_GRP1_EnableClock(LL_APB2_GRP1_PERIPH_USART1);
+  
+  /**USART1 GPIO Configuration  
+  PB6   ------> USART1_TX
+  PB7   ------> USART1_RX 
+  */
+  GPIO_InitStruct.Pin = LL_GPIO_PIN_6|LL_GPIO_PIN_7;
+  GPIO_InitStruct.Mode = LL_GPIO_MODE_ALTERNATE;
+  GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_VERY_HIGH;
+  GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
+  GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
+  GPIO_InitStruct.Alternate = LL_GPIO_AF_7;
+  LL_GPIO_Init(GPIOB, &GPIO_InitStruct);
+
+  USART_InitStruct.BaudRate = 115200;
+  USART_InitStruct.DataWidth = LL_USART_DATAWIDTH_8B;
+  USART_InitStruct.StopBits = LL_USART_STOPBITS_1;
+  USART_InitStruct.Parity = LL_USART_PARITY_NONE;
+  USART_InitStruct.TransferDirection = LL_USART_DIRECTION_TX_RX;
+  USART_InitStruct.HardwareFlowControl = LL_USART_HWCONTROL_NONE;
+  USART_InitStruct.OverSampling = LL_USART_OVERSAMPLING_16;
+  LL_USART_Init(USART1, &USART_InitStruct);
+
+  LL_USART_ConfigAsyncMode(USART1);
+
+  LL_USART_Enable(USART1);
+
+}
+
+/** Pinout Configuration
+*/
+static void MX_GPIO_Init(void)
+{
+
+  /* GPIO Ports Clock Enable */
+  LL_AHB2_GRP1_EnableClock(LL_AHB2_GRP1_PERIPH_GPIOA);
+  LL_AHB2_GRP1_EnableClock(LL_AHB2_GRP1_PERIPH_GPIOB);
+
+}
+
+
+/* TIM6 init function */
+static void MX_TIM6_Init(void)
+{
+
+  LL_TIM_InitTypeDef TIM_InitStruct;
+
+  /* Peripheral clock enable */
+  LL_APB1_GRP1_EnableClock(LL_APB1_GRP1_PERIPH_TIM6);
+
+  // 48 MHz sys clock --> 6 MHz timer clock
+  // 6 MHz / 6000 == 1000 Hz
+  TIM_InitStruct.Prescaler = 6000;
+  TIM_InitStruct.CounterMode = LL_TIM_COUNTERMODE_UP;
+  TIM_InitStruct.Autoreload = 0xffff;
+  LL_TIM_Init(TIM6, &TIM_InitStruct);
+
+  LL_TIM_DisableARRPreload(TIM6);
+
+  LL_TIM_SetTriggerOutput(TIM6, LL_TIM_TRGO_RESET);
+
+  LL_TIM_DisableMasterSlaveMode(TIM6);
+
+  // enable interrupt
+  TIM6->DIER |= 1;
+
+  // Start immediately
+  LL_TIM_EnableCounter(TIM6);
+}

targets/stm32l442/src/main.c

@@ -1,4 +1,5 @@
 #include <stdint.h>
+#include <stdio.h>
 #include "stm32l4xx.h"
 #include "stm32l4xx_ll_gpio.h"
 #include "stm32l4xx_ll_rcc.h"
@@ -9,174 +10,164 @@
 #include "stm32l4xx_ll_gpio.h"
 #include "stm32l4xx_ll_usart.h"
 #include "stm32l4xx_ll_bus.h"
+#include "stm32l4xx_ll_tim.h"
+
+#include "app.h"
 
 #define Error_Handler() _Error_Handler(__FILE__,__LINE__)
 
-#define VCP_TX_Pin LL_GPIO_PIN_6
-#define VCP_RX_Pin LL_GPIO_PIN_7
-#define VCP_TX_GPIO_Port GPIOB
-#define VCP_RX_GPIO_Port GPIOB
-
-void _Error_Handler(char *file, int line);
-
-void delay(uint32_t ms)
-{
-    volatile int x,y;
-    for (x=0; x < 100; x++)
-        for (y=0; y < ms * 20; y++)
-            ;
-}
-
-void uart_write(USART_TypeDef *uart, uint8_t * data, uint32_t len)
-{
-    while(len--)
-    {
-        while (! LL_USART_IsActiveFlag_TXE(uart))
-            ;
-        LL_USART_TransmitData8(uart,*data++);
-    }
-}
-
-void MX_USART1_UART_Init(void)
-{
-
-  LL_USART_InitTypeDef USART_InitStruct;
-
-  LL_GPIO_InitTypeDef GPIO_InitStruct;
-
-  /* Peripheral clock enable */
-  LL_APB2_GRP1_EnableClock(LL_APB2_GRP1_PERIPH_USART1);
-  
-  /**USART1 GPIO Configuration  
-  PB6   ------> USART1_TX
-  PB7   ------> USART1_RX 
-  */
-  GPIO_InitStruct.Pin = LL_GPIO_PIN_6|LL_GPIO_PIN_7;
-  GPIO_InitStruct.Mode = LL_GPIO_MODE_ALTERNATE;
-  GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_VERY_HIGH;
-  GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
-  GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
-  GPIO_InitStruct.Alternate = LL_GPIO_AF_7;
-  LL_GPIO_Init(GPIOB, &GPIO_InitStruct);
-
-  USART_InitStruct.BaudRate = 115200;
-  USART_InitStruct.DataWidth = LL_USART_DATAWIDTH_8B;
-  USART_InitStruct.StopBits = LL_USART_STOPBITS_1;
-  USART_InitStruct.Parity = LL_USART_PARITY_NONE;
-  USART_InitStruct.TransferDirection = LL_USART_DIRECTION_TX_RX;
-  USART_InitStruct.HardwareFlowControl = LL_USART_HWCONTROL_NONE;
-  USART_InitStruct.OverSampling = LL_USART_OVERSAMPLING_16;
-  LL_USART_Init(USART1, &USART_InitStruct);
-
-  LL_USART_ConfigAsyncMode(USART1);
-
-  LL_USART_Enable(USART1);
-
-}
-
-// Generated via cube
-void SystemClock_Config(void)
-{
-
-  LL_FLASH_SetLatency(LL_FLASH_LATENCY_2);
-
-   if(LL_FLASH_GetLatency() != LL_FLASH_LATENCY_2)
-  {
-  Error_Handler();  
-  }
-  LL_PWR_SetRegulVoltageScaling(LL_PWR_REGU_VOLTAGE_SCALE1);
-
-  LL_RCC_MSI_Enable();
-
-   /* Wait till MSI is ready */
-  while(LL_RCC_MSI_IsReady() != 1)
-  {
-    
-  }
-  LL_RCC_MSI_EnableRangeSelection();
-
-  LL_RCC_MSI_SetRange(LL_RCC_MSIRANGE_11);
-
-  LL_RCC_MSI_SetCalibTrimming(0);
-
-  LL_RCC_SetSysClkSource(LL_RCC_SYS_CLKSOURCE_MSI);
-
-   /* Wait till System clock is ready */
-  while(LL_RCC_GetSysClkSource() != LL_RCC_SYS_CLKSOURCE_STATUS_MSI)
-  {
-  
-  }
-  LL_RCC_SetAHBPrescaler(LL_RCC_SYSCLK_DIV_1);
-
-  LL_RCC_SetAPB1Prescaler(LL_RCC_APB1_DIV_16);
-
-  LL_RCC_SetAPB2Prescaler(LL_RCC_APB2_DIV_16);
-
-  LL_Init1msTick(48000000);
-
-  LL_SYSTICK_SetClkSource(LL_SYSTICK_CLKSOURCE_HCLK);
-
-  LL_SetSystemCoreClock(48000000);
-
-  LL_RCC_SetUSARTClockSource(LL_RCC_USART1_CLKSOURCE_PCLK2);
-
-  /* SysTick_IRQn interrupt configuration */
-  NVIC_SetPriority(SysTick_IRQn, NVIC_EncodePriority(NVIC_GetPriorityGrouping(),0, 0));
-}
-
 #define LED_PIN_G     LL_GPIO_PIN_0
 #define LED_PIN_B     LL_GPIO_PIN_1
 #define LED_PIN_R     LL_GPIO_PIN_2
 #define LED_PORT    GPIOA
-void hw_init()
+
+void hw_init(void);
+
+void delay(uint32_t ms)
+{
+    uint32_t time = millis();
+    while ((millis() - time) < ms)
+        ;
+}
+
+void rgb(uint32_t hex)
+{
+    uint32_t r = hex >> 16;
+    uint32_t g = (hex >> 8)&0xff;
+    uint32_t b = hex & 0xff;
+
+    // CCR2 == blue
+    // CCR3 == red
+    // CCR4 == green
+
+    // map and scale colors
+    TIM2->CCR2 = 1000 - (b * 1000)/(256);
+    TIM2->CCR3 = 1000 - (r * 1000)/(256*6);
+    TIM2->CCR4 = 1000 - (g * 1000)/(256);
+}
+
+void test_colors()
+{
+    // Should produce pulsing of various colors
+    int i = 0;
+    int j = 0;
+    int inc = 1;
+    uint32_t time = 0;
+#define update() do {\
+        i += inc;\
+        if (i > 254)\
+        {\
+            inc *= -1;\
+        }\
+        else if (i == 0)\
+        {\
+            inc *= -1;\
+        }\
+        delay(2);\
+        }while(0);
+
+    while(1)
     {
 
-    /*SystemClock_Config();*/
-    // initialize GPIO
-    // Enable clock to A,B,C
-    SET_BIT(RCC->AHB2ENR, RCC_AHB2ENR_GPIOAEN);
-    SET_BIT(RCC->AHB2ENR, RCC_AHB2ENR_GPIOBEN);
-    SET_BIT(RCC->AHB2ENR, RCC_AHB2ENR_GPIOCEN);
-    LL_GPIO_SetPinMode(LED_PORT, LED_PIN_R, LL_GPIO_MODE_OUTPUT);
-    LL_GPIO_SetPinMode(LED_PORT, LED_PIN_G, LL_GPIO_MODE_OUTPUT);
-    LL_GPIO_SetPinMode(LED_PORT, LED_PIN_B, LL_GPIO_MODE_OUTPUT);
-    /*  NVIC_SetPriorityGrouping(NVIC_PRIORITYGROUP_4);*/
-    /*SystemClock_Config();*/
+        printf("%d: %d\r\n", j++, millis());
+
+        printf("white pulse\r\n");
+        time = millis();
+        while((millis() - time) < 5000)
+        {
+            update();
+            rgb(i | (i << 8) | (i << 16));
+        }
+
+        printf("blue pulse\r\n");
+        time = millis();
+        while((millis() - time) < 5000)
+        {
+            update();
+            rgb(i);
+        }
+
+        printf("green pulse\r\n");
+        time = millis();
+        while((millis() - time) < 5000)
+        {
+            update();
+            rgb(i<<8);
+        }
+
+        printf("red pulse\r\n");
+        time = millis();
+        while((millis() - time) < 5000)
+        {
+            update();
+            rgb(i<<16);
+        }
+
+        printf("purple pulse\r\n");
+        time = millis();
+        while((millis() - time) < 5000)
+        {
+            update();
+            rgb((i<<16) | i);
+        }
+
+        printf("orange pulse\r\n");
+        time = millis();
+        while((millis() - time) < 5000)
+        {
+            update();
+            rgb((i<<16) | (i<<8));
+        }
+
+        printf("yellow pulse\r\n");
+        time = millis();
+        while((millis() - time) < 5000)
+        {
+            update();
+            rgb((i<<8) | (i<<0));
+        }
+
+    }
 
 
-    /*MX_USART1_UART_Init();*/
+
+}
+
+uint32_t __65_seconds = 0;
+void TIM6_DAC_IRQHandler()
+{
+    // timer is only 16 bits, so roll it over here
+    TIM6->SR = 0;
+    __65_seconds += 1;
 }
 
 int main(void)
 {
-    uint8_t msg[] = "hi  !\r\n";
-    int i = 'A';
+    uint32_t i = 0;
+    int inc = 1;
     hw_init();
 
+
+    /*LL_GPIO_SetPinMode(LED_PORT, LED_PIN_R, LL_GPIO_MODE_OUTPUT);*/
+    /*LL_GPIO_SetPinMode(LED_PORT, LED_PIN_G, LL_GPIO_MODE_OUTPUT);*/
+    /*LL_GPIO_SetPinMode(LED_PORT, LED_PIN_B, LL_GPIO_MODE_OUTPUT);*/
+
+    /*LL_GPIO_SetOutputPin(LED_PORT, LED_PIN_R);*/
+    /*LL_GPIO_SetOutputPin(LED_PORT, LED_PIN_G);*/
+    /*LL_GPIO_SetOutputPin(LED_PORT, LED_PIN_B);*/
+    test_colors();
+
+
     while (1)
     {
-        /*LL_GPIO_TogglePin(LED_PORT, LED_PIN_R);*/
-        /*LL_GPIO_TogglePin(LED_PORT, LED_PIN_R);*/
-        /*LL_GPIO_TogglePin(LED_PORT, LED_PIN_G);*/
-        /*LL_GPIO_TogglePin(LED_PORT, LED_PIN_B);*/
+        rgb(i | (i << 8) | (i << 16));
 
-        LL_GPIO_SetOutputPin(LED_PORT, LED_PIN_R);
-        LL_GPIO_SetOutputPin(LED_PORT, LED_PIN_G);
-        LL_GPIO_SetOutputPin(LED_PORT, LED_PIN_B);
-
-        LL_GPIO_ResetOutputPin(LED_PORT, LED_PIN_R);
-        /*LL_GPIO_ResetOutputPin(LED_PORT, LED_PIN_G);*/
-        /*LL_GPIO_ResetOutputPin(LED_PORT, LED_PIN_B);*/
-
-
-        /*delay(10);*/
-        msg[3] = i++;
-        while (1)
-            ;
-        /*uart_write(USART2, msg, sizeof(msg));*/
+        delay(100);
+        printf("%d: %d\r\n", i++, millis());
     }
 }
 
+
 void _Error_Handler(char *file, int line)
 {
 
@@ -185,3 +176,4 @@ void _Error_Handler(char *file, int line)
     }
 }
 
+

targets/stm32l442/src/redirect.c

@@ -0,0 +1,21 @@
+#include "stm32l4xx_ll_usart.h"
+
+#include "app.h"
+
+void _putchar(char c)
+{
+    while (! LL_USART_IsActiveFlag_TXE(DEBUG_UART))
+        ;
+    LL_USART_TransmitData8(DEBUG_UART,c);
+}
+
+int _write (int fd, const void *buf, long int len)
+{
+    uint8_t * data = (uint8_t *) buf;
+    while(len--)
+    {
+        _putchar(*data++);
+    }
+    return 0;
+}
+