From ea151c42850182ae615090a47a8629a5d3b46bdb Mon Sep 17 00:00:00 2001
From: Thomas Klaehn <thomas.klaehn@perinet.io>
Date: Mon, 5 Jul 2021 16:23:27 +0200
Subject: [PATCH] I2c tx/rx non-blocking

---
 Core/Src/main.c         | 25 ++++++++++++++++---------
 Core/Src/stm32g0xx_it.c | 19 ++++++++++++++-----
 Makefile                | 16 ++++++++--------
 3 files changed, 38 insertions(+), 22 deletions(-)

diff --git a/Core/Src/main.c b/Core/Src/main.c
index 2bda898..79daaa9 100644
--- a/Core/Src/main.c
+++ b/Core/Src/main.c
@@ -8,6 +8,8 @@
 UART_HandleTypeDef huart2;
 I2C_HandleTypeDef hi2c1;
 
+uint8_t data[2] = {0};
+
 void SystemClock_Config(void);
 static void MX_GPIO_Init(void);
 static void MX_USART2_UART_Init(void);
@@ -35,21 +37,26 @@ int main(void)
     MX_USART2_UART_Init();
     MX_I2C1_Init();
 
-    uint8_t data[2] = {0};
     data[0] = 1; // Config register
-    if(HAL_I2C_Master_Transmit(&hi2c1, (uint16_t)(0x48 << 1), data,1, 1000) != HAL_OK) {
+    if(HAL_I2C_Master_Transmit_IT(&hi2c1, (uint16_t)(0x48 << 1), data, 1) != HAL_OK) {
         printf("I2c tx failed.\r\n");
-    } else {
-        if(HAL_I2C_Master_Receive(&hi2c1, (uint16_t)(0x48 << 1), data, 2, 1000) != HAL_OK) {
-            printf("I2c rx failed.\r\n");
-        } else {
-            uint16_t config = (uint16_t)(data[0] << 8) | data[1];
-            printf("ADS1115 config register: 0x%04x\r\n", config);
-        }
     }
     while(1) {};
 }
 
+void HAL_I2C_MasterTxCpltCallback(I2C_HandleTypeDef *hi2c)
+{
+    if(HAL_I2C_Master_Receive_IT(&hi2c1, (uint16_t)(0x48 << 1), data, 2) != HAL_OK) {
+        printf("I2c rx failed.\r\n");
+    }
+}
+
+void HAL_I2C_MasterRxCpltCallback(I2C_HandleTypeDef *hi2c)
+{
+    uint16_t config = (uint16_t)(data[0] << 8) | data[1];
+    printf("ADS1115 config register: 0x%04x\r\n", config);
+}
+
 void SystemClock_Config(void)
 {
     RCC_OscInitTypeDef RCC_OscInitStruct = {0};
diff --git a/Core/Src/stm32g0xx_it.c b/Core/Src/stm32g0xx_it.c
index 6fdeefb..6b8449b 100644
--- a/Core/Src/stm32g0xx_it.c
+++ b/Core/Src/stm32g0xx_it.c
@@ -1,16 +1,16 @@
 #include "main.h"
 #include "stm32g0xx_it.h"
 
+extern I2C_HandleTypeDef hi2c1;
+
 void NMI_Handler(void)
 {
-	while (1) {
-	}
+    while (1) {}
 }
 
 void HardFault_Handler(void)
 {
-	while (1) {
-	}
+    while (1) {}
 }
 
 void SVC_Handler(void)
@@ -23,5 +23,14 @@ void PendSV_Handler(void)
 
 void SysTick_Handler(void)
 {
-  HAL_IncTick();
+    HAL_IncTick();
+}
+
+void I2C1_IRQHandler(void)
+{
+    if(hi2c1.Instance->ISR & (I2C_FLAG_BERR | I2C_FLAG_ARLO | I2C_FLAG_OVR)) {
+        HAL_I2C_ER_IRQHandler(&hi2c1);
+    } else {
+        HAL_I2C_EV_IRQHandler(&hi2c1);
+    }
 }
diff --git a/Makefile b/Makefile
index a54e531..e54bca9 100644
--- a/Makefile
+++ b/Makefile
@@ -12,18 +12,18 @@ Core/Src/stm32g0xx_hal_msp.c \
 Core/Src/system_stm32g0xx.c \
 Core/Src/syscalls.c \
 Core/Src/sysmem.c \
-Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_rcc.c \
 Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal.c \
 Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_cortex.c \
-Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_rcc_ex.c \
+Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_gpio.c \
+Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_dma.c \
+Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_i2c.c \
+Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_i2c_ex.c \
 Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_pwr.c \
 Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_pwr_ex.c \
-Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_iwdg.c \
+Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_rcc.c \
+Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_rcc_ex.c \
 Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_uart_ex.c \
-Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_uart.c \
-Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_gpio.c \
-Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_i2c.c \
-Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_i2c_ex.c
+Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_uart.c
 
 ASM_SOURCES = \
 Core/Startup/startup_stm32g031y8yx.s
@@ -64,7 +64,7 @@ LIBS = -lc -lm -lnosys
 LIBDIR =
 LDFLAGS = $(MCU) -specs=nano.specs -T$(LDSCRIPT) $(LIBDIR) $(LIBS) -Wl,-Map=$(BUILD_DIR)/$(TARGET).map,--cref -Wl,--gc-sections
 
-all: $(BUILD_DIR)/$(TARGET).elf $(BUILD_DIR)/$(TARGET).hex $(BUILD_DIR)/$(TARGET).bin
+all: $(BUILD_DIR)/$(TARGET).elf
 
 OBJECTS = $(addprefix $(BUILD_DIR)/,$(notdir $(C_SOURCES:.c=.o)))
 vpath %.c $(sort $(dir $(C_SOURCES)))