working synchronous usart

Author: GabeMillikan

ECU/Core/Src/main.c

@@ -117,7 +117,6 @@ int main(void)
 
 	/* Infinite loop */
 	/* USER CODE BEGIN WHILE */
-	uint8_t buffer[128];
 	USARTConfig config;
 	USARTHandle handle = usart_init_peripheral(&config);
 	while (1) {

Lib/Inhouse/Peripherals/USART/usart.c

@@ -1,54 +1,55 @@
 #include "usart.h"
+#include "Logomatic.h"
 #include "string.h"
 
 #include "usart_ll_platform_deps.h"
 
 USARTHandle usart_init_peripheral(USARTConfig *config)
 {
 	USARTHandle handle;
-	handle.baud_rate = config->baud_rate;
 
-	LL_USART_InitTypeDef USART_InitStruct = {0};
-	LL_GPIO_InitTypeDef GPIO_InitStruct = {0};
-
-	// TODO: this should come from USARTConfig
-	/**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_LOW;
-	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);
-
-	NVIC_SetPriority(USART1_IRQn,
-			 NVIC_EncodePriority(NVIC_GetPriorityGrouping(), 0, 0));
-	NVIC_EnableIRQ(USART1_IRQn);
-
-	USART_InitStruct.PrescalerValue = LL_USART_PRESCALER_DIV1;
-	USART_InitStruct.BaudRate = config->baud_rate;
-	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_SetTXFIFOThreshold(USART1, LL_USART_FIFOTHRESHOLD_1_8);
-	LL_USART_SetRXFIFOThreshold(USART1, LL_USART_FIFOTHRESHOLD_1_8);
-	LL_USART_DisableFIFO(USART1);
+	// Enable GPIOB and USART1 clocks
+	LL_AHB2_GRP1_EnableClock(LL_AHB2_GRP1_PERIPH_GPIOB);
+	LL_APB2_GRP1_EnableClock(LL_APB2_GRP1_PERIPH_USART1);
+
+	// Select PCLK2 as USART1 clock source
+	LL_RCC_SetUSARTClockSource(LL_RCC_USART1_CLKSOURCE_PCLK2);
+
+	// Configure PB6 = TX, PB7 = RX
+	LL_GPIO_InitTypeDef gpio = {0};
+	gpio.Pin = LL_GPIO_PIN_6 | LL_GPIO_PIN_7;
+	gpio.Mode = LL_GPIO_MODE_ALTERNATE;
+	gpio.Alternate = LL_GPIO_AF_7;
+	gpio.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
+	gpio.Pull = LL_GPIO_PULL_UP;
+	gpio.Speed = LL_GPIO_SPEED_FREQ_HIGH;
+	LL_GPIO_Init(GPIOB, &gpio);
+
+	// Configure USART
+	LL_USART_InitTypeDef us = {0};
+	us.PrescalerValue = LL_USART_PRESCALER_DIV1;
+	us.BaudRate = config->baud_rate;
+	us.DataWidth = LL_USART_DATAWIDTH_8B;
+	us.StopBits = LL_USART_STOPBITS_1;
+	us.Parity = LL_USART_PARITY_NONE;
+	us.TransferDirection = LL_USART_DIRECTION_TX_RX;
+	us.HardwareFlowControl = LL_USART_HWCONTROL_NONE;
+	us.OverSampling = LL_USART_OVERSAMPLING_16;
+	LL_USART_Init(USART1, &us);
+
 	LL_USART_ConfigAsyncMode(USART1);
 
+	// Enable TX/RX explicitly and enable USART
+	LL_USART_EnableDirectionTx(USART1);
+	LL_USART_EnableDirectionRx(USART1);
 	LL_USART_Enable(USART1);
 
-	while ((!(LL_USART_IsActiveFlag_TEACK(USART1))) ||
-	       (!(LL_USART_IsActiveFlag_REACK(USART1)))) {
+	// Wait for TEACK/REACK
+	while (!LL_USART_IsActiveFlag_TEACK(USART1) ||
+	       !LL_USART_IsActiveFlag_REACK(USART1)) {
 	}
 
+	handle.baud_rate = config->baud_rate;
 	return handle;
 }
 
@@ -62,10 +63,15 @@ void usart_send(USARTHandle *handle, uint8_t *data, uint32_t size)
 		size = strlen((char *)data);
 	}
 	for (uint32_t i = 0; i < size; i++) {
-		while (!LL_USART_IsActiveFlag_TXE(USART1))
-			;
+		while (!LL_USART_IsActiveFlag_TXE_TXFNF(USART1)) {
+			LOGOMATIC("Waiting for TXE flag...\n");
+		}
 		LL_USART_TransmitData8(USART1, data[i]);
 	}
+
+	// wait for final byte to transmit
+	while (!LL_USART_IsActiveFlag_TXE_TXFNF(USART1))
+		;
 }
 
 uint32_t usart_receive(USARTHandle *handle, uint8_t *buffer, uint32_t size,

Lib/Inhouse/Peripherals/USART/usart_ll_platform_deps.h

@@ -1,11 +1,17 @@
 #ifdef STM32L476xx
+#include "stm32l4xx_ll_bus.h"
 #include "stm32l4xx_ll_gpio.h"
+#include "stm32l4xx_ll_rcc.h"
 #include "stm32l4xx_ll_usart.h"
 #elif defined(STM32G474xx)
+#include "stm32g4xx_ll_bus.h"
 #include "stm32g4xx_ll_gpio.h"
+#include "stm32g4xx_ll_rcc.h"
 #include "stm32g4xx_ll_usart.h"
 #elif defined(STM32U5A9xx)
+#include "stm32u5xx_ll_bus.h"
 #include "stm32u5xx_ll_gpio.h"
+#include "stm32u5xx_ll_rcc.h"
 #include "stm32u5xx_ll_usart.h"
 #else
 #error "Unsupported STM32 family"