make it work!

Core/Inc/i2c_gateway.h

@@ -0,0 +1,9 @@
+#ifndef I2C_GATEWAY_H
+#define I2C_GATEWAY_H
+
+#include <stdint.h>
+#include <stddef.h>
+
+void i2c_command(uint8_t *packet, size_t len);
+
+#endif //I2C_GATEWAY_H

Core/Inc/stm32f1xx_it.h

@@ -55,6 +55,8 @@ void DebugMon_Handler(void);
 void USB_HP_CAN1_TX_IRQHandler(void);
 void USB_LP_CAN1_RX0_IRQHandler(void);
 void TIM1_UP_IRQHandler(void);
+void I2C1_EV_IRQHandler(void);
+void I2C1_ER_IRQHandler(void);
 /* USER CODE BEGIN EFP */
 
 /* USER CODE END EFP */

Core/Src/freertos.c

@@ -150,14 +150,14 @@ void StartDefaultTask(void *argument)
 
     //HAL_HalfDuplex_EnableTransmitter(&huart1);
     /* Infinite loop */
-    int cnt = 0;
+    //int cnt = 0;
     for (;;) {
         vTaskDelay(pdMS_TO_TICKS(500));
 
         HAL_IWDG_Refresh(&hiwdg);
         HAL_GPIO_TogglePin(LED_GPIO_Port, LED_Pin);
 
-        printf("Hello, count is %d\r\n", cnt++);
+        //printf("Hello, count is %d\r\n", cnt++);
     }
 
   /* USER CODE END StartDefaultTask */

Core/Src/i2c.c

@@ -45,7 +45,7 @@ void MX_I2C1_Init(void)
   hi2c1.Init.DualAddressMode = I2C_DUALADDRESS_DISABLE;
   hi2c1.Init.OwnAddress2 = 0;
   hi2c1.Init.GeneralCallMode = I2C_GENERALCALL_DISABLE;
-  hi2c1.Init.NoStretchMode = I2C_NOSTRETCH_ENABLE;
+  hi2c1.Init.NoStretchMode = I2C_NOSTRETCH_DISABLE;
   if (HAL_I2C_Init(&hi2c1) != HAL_OK)
   {
     Error_Handler();
@@ -78,6 +78,12 @@ void HAL_I2C_MspInit(I2C_HandleTypeDef* i2cHandle)
 
     /* I2C1 clock enable */
     __HAL_RCC_I2C1_CLK_ENABLE();
+
+    /* I2C1 interrupt Init */
+    HAL_NVIC_SetPriority(I2C1_EV_IRQn, 5, 0);
+    HAL_NVIC_EnableIRQ(I2C1_EV_IRQn);
+    HAL_NVIC_SetPriority(I2C1_ER_IRQn, 5, 0);
+    HAL_NVIC_EnableIRQ(I2C1_ER_IRQn);
   /* USER CODE BEGIN I2C1_MspInit 1 */
 
   /* USER CODE END I2C1_MspInit 1 */
@@ -103,6 +109,9 @@ void HAL_I2C_MspDeInit(I2C_HandleTypeDef* i2cHandle)
 
     HAL_GPIO_DeInit(GPIOB, GPIO_PIN_7);
 
+    /* I2C1 interrupt Deinit */
+    HAL_NVIC_DisableIRQ(I2C1_EV_IRQn);
+    HAL_NVIC_DisableIRQ(I2C1_ER_IRQn);
   /* USER CODE BEGIN I2C1_MspDeInit 1 */
 
   /* USER CODE END I2C1_MspDeInit 1 */

Core/Src/i2c_gateway.c

@@ -0,0 +1,181 @@
+#include <stdint.h>
+#include <stdio.h>
+#include "main.h"
+#include "usbd_cdc_if.h"
+
+#define I2C_DEBUG 0
+
+#define I2C_MTU 512
+
+#define HAL_CHECK(x) do { \
+    int rv = (x);         \
+    if (rv != HAL_OK) {   \
+        printf("HAL ERR %d at %s:%d\r\n", rv, __FILE__, __LINE__);  \
+    }\
+} while (0)
+
+/**
+ * Packet format:
+ *
+ * Transmit packets
+ *   LEN_MSB LEN_LSB ADDR Bytes...
+ *
+ * LEN does not include the length field itself!
+ *
+ * Command packets are sent as ADDR=255
+ *   0xFF CMD ARGs...
+ *   - Set address: 0x01 ADDR
+ *   - Set speed:   0x02 Speed TODO!!
+ *     - Speed 1 ... 100kHz
+ *     - Speed 4 ... 400kHz
+ */
+
+#define COMMAND_ADDRESS 0xFF
+#define CMD_SET_ADDR  1  // the next param is the address, without shifting (i.e. 1-127)
+#define CMD_SET_SPEED 2  // speed is 1 or 4 (100khz, 400khz)
+
+enum FrameState {
+    FRAME_LEN_MSB,
+    FRAME_LEN_LSB,
+    FRAME_PAYLOAD,
+};
+
+static uint16_t framelen = 0;
+static uint8_t i2c_recbuf[I2C_MTU + 3] = {};
+static size_t recbuf_wp = 0;
+static size_t framestate = FRAME_LEN_MSB;
+static uint32_t last_rx_tick;
+#define CMD_TIMEOUT_TICKS 500
+
+
+static void handle_pkt(uint8_t *packet, size_t len);
+static void handle_control_pkt(uint8_t *packet, size_t len);
+
+void i2c_command(uint8_t *packet, size_t len)
+{
+    uint32_t now = HAL_GetTick();
+    if (framestate != FRAME_LEN_MSB && (now - last_rx_tick) > CMD_TIMEOUT_TICKS) {
+        framestate = FRAME_LEN_MSB;
+    }
+    last_rx_tick = now;
+
+    for (int i=0; i<len;i++) {
+        uint8_t b = packet[i];
+        switch (framestate) {
+            case FRAME_LEN_MSB:
+                framelen = ((uint16_t)b) << 8;
+                framestate = FRAME_LEN_LSB;
+                break;
+            case FRAME_LEN_LSB:
+                framelen |= (uint16_t)b;
+                if (framelen == 0) {
+                    framestate = FRAME_LEN_MSB;
+                } else {
+                    framestate = FRAME_PAYLOAD;
+                    recbuf_wp = 0;
+                }
+                break;
+            case FRAME_PAYLOAD:
+                i2c_recbuf[recbuf_wp++] = b;
+                if (recbuf_wp >= framelen) {
+                    handle_pkt(i2c_recbuf, framelen);
+                    framestate = FRAME_LEN_MSB;
+                }
+                break;
+        }
+    }
+}
+
+static void handle_pkt(uint8_t *packet, size_t len)
+{
+#if I2C_DEBUG
+    printf("Handle packet (%d bytes): ", len);
+    for(int i=0; i<len;i++) {
+        printf("%02x ", packet[i]);
+    }
+    printf("\r\n");
+#endif
+
+    if (packet[0] == COMMAND_ADDRESS) {
+        printf("ctl: ");
+        // This is an in-band control packet
+        handle_control_pkt(packet, len);
+    } else {
+        uint8_t dest = packet[0];
+
+#if I2C_DEBUG
+        printf("Tx(%d)->%d\r\n", len - 1, dest);
+#endif
+
+        // Blocking transfer
+        HAL_CHECK(HAL_I2C_DisableListen_IT(&hi2c1));
+        HAL_CHECK(HAL_I2C_Master_Transmit(&hi2c1, (dest & 0x7F) << 1, &packet[1], len - 1, 100));
+        HAL_CHECK(HAL_I2C_EnableListen_IT(&hi2c1));
+    }
+}
+
+static void handle_control_pkt(uint8_t *packet, size_t len)
+{
+    uint8_t cmd = packet[1];
+    uint8_t arg;
+
+    switch (cmd) {
+        case CMD_SET_ADDR:
+            if (len < 3) return;
+            arg = packet[2];
+            printf("Addr=0x%02x\r\n", arg);
+            MODIFY_REG(hi2c1.Instance->OAR1,
+                       (I2C_OAR1_ADDMODE | I2C_OAR1_ADD8_9 | I2C_OAR1_ADD1_7 | I2C_OAR1_ADD0),
+                       (I2C_ADDRESSINGMODE_7BIT | ((arg & 0x7F) << 1) ));
+            HAL_CHECK(HAL_I2C_EnableListen_IT(&hi2c1));
+            break;
+
+        default:
+            printf("bad cmd!\r\n");
+    }
+}
+
+/**
+  * @brief  Slave Address Match callback.
+  * @param  hi2c Pointer to a I2C_HandleTypeDef structure that contains
+  *                the configuration information for the specified I2C.
+  * @param  TransferDirection Master request Transfer Direction (Write/Read), value of @ref I2C_XferDirection_definition
+  * @param  AddrMatchCode Address Match Code
+  * @retval None
+  */
+void HAL_I2C_AddrCallback(I2C_HandleTypeDef *hi2c, uint8_t TransferDirection, uint16_t AddrMatchCode)
+{
+    HAL_CHECK(HAL_I2C_Slave_Seq_Receive_IT(hi2c, i2c_recbuf, I2C_MTU, I2C_FIRST_AND_LAST_FRAME));
+}
+
+/**
+  * @brief  Slave Rx Transfer completed callback.
+  * @param  hi2c Pointer to a I2C_HandleTypeDef structure that contains
+  *                the configuration information for the specified I2C.
+  * @retval None
+  */
+void HAL_I2C_SlaveRxCpltCallback(I2C_HandleTypeDef *hi2c)
+{
+    int numBytes = I2C_MTU - hi2c->XferCount;
+#if I2C_DEBUG
+    printf("rxd %d\r\n", numBytes);
+#endif
+
+    UserTxBufferFS[0] = (numBytes >> 8) & 0xFF;
+    UserTxBufferFS[1] = numBytes & 0xFF;
+    memcpy(&UserTxBufferFS[2], i2c_recbuf, numBytes);
+
+    CDC_Transmit_FS(UserTxBufferFS, numBytes + 2);
+}
+
+/**
+  * @brief  Listen Complete callback.
+  * @param  hi2c Pointer to a I2C_HandleTypeDef structure that contains
+  *                the configuration information for the specified I2C.
+  * @retval None
+  */
+void HAL_I2C_ListenCpltCallback(I2C_HandleTypeDef *hi2c)
+{
+    // Start again
+    HAL_CHECK(HAL_I2C_EnableListen_IT(hi2c));
+}

Core/Src/stm32f1xx_it.c

@@ -56,6 +56,7 @@
 
 /* External variables --------------------------------------------------------*/
 extern PCD_HandleTypeDef hpcd_USB_FS;
+extern I2C_HandleTypeDef hi2c1;
 extern TIM_HandleTypeDef htim1;
 
 /* USER CODE BEGIN EV */
@@ -202,6 +203,34 @@ void TIM1_UP_IRQHandler(void)
   /* USER CODE END TIM1_UP_IRQn 1 */
 }
 
+/**
+  * @brief This function handles I2C1 event interrupt.
+  */
+void I2C1_EV_IRQHandler(void)
+{
+  /* USER CODE BEGIN I2C1_EV_IRQn 0 */
+
+  /* USER CODE END I2C1_EV_IRQn 0 */
+  HAL_I2C_EV_IRQHandler(&hi2c1);
+  /* USER CODE BEGIN I2C1_EV_IRQn 1 */
+
+  /* USER CODE END I2C1_EV_IRQn 1 */
+}
+
+/**
+  * @brief This function handles I2C1 error interrupt.
+  */
+void I2C1_ER_IRQHandler(void)
+{
+  /* USER CODE BEGIN I2C1_ER_IRQn 0 */
+
+  /* USER CODE END I2C1_ER_IRQn 0 */
+  HAL_I2C_ER_IRQHandler(&hi2c1);
+  /* USER CODE BEGIN I2C1_ER_IRQn 1 */
+
+  /* USER CODE END I2C1_ER_IRQn 1 */
+}
+
 /* USER CODE BEGIN 1 */
 
 /* USER CODE END 1 */

Drivers/STM32F1xx_HAL_Driver/Src/stm32f1xx_hal_i2c.c

@@ -6356,12 +6356,13 @@ static void I2C_Slave_STOPF(I2C_HandleTypeDef *hi2c)
 
     if (hi2c->XferCount != 0U)
     {
-      /* Set ErrorCode corresponding to a Non-Acknowledge */
+        /* Set ErrorCode corresponding to a Non-Acknowledge */
-      hi2c->ErrorCode |= HAL_I2C_ERROR_AF;
+        hi2c->ErrorCode |= HAL_I2C_ERROR_AF;
     }
   }
 
-  if (hi2c->ErrorCode != HAL_I2C_ERROR_NONE)
+  // HACK - ignore HAL_I2C_ERROR_AF
+  if (hi2c->ErrorCode != HAL_I2C_ERROR_NONE && hi2c->ErrorCode != HAL_I2C_ERROR_AF)
   {
     /* Call the corresponding callback to inform upper layer of End of Transfer */
     I2C_ITError(hi2c);

Makefile

@@ -1,5 +1,5 @@
 ##########################################################################################################################
-# File automatically-generated by tool: [projectgenerator] version: [3.16.0] date: [Fri Apr 01 20:27:44 CEST 2022] 
+# File automatically-generated by tool: [projectgenerator] version: [3.16.0] date: [Fri Apr 01 20:41:48 CEST 2022]
 ##########################################################################################################################
 
 .PHONY: flash
@@ -40,6 +40,7 @@ BUILD_DIR = build
 C_SOURCES =  \
 Core/Src/main.c \
 Core/Src/logging.c \
+Core/Src/i2c_gateway.c \
 Core/Src/freertos.c \
 Core/Src/stm32f1xx_it.c \
 Core/Src/stm32f1xx_hal_msp.c \

USB_DEVICE/App/usbd_cdc_if.c

@@ -22,6 +22,7 @@
 #include "usbd_cdc_if.h"
 
 /* USER CODE BEGIN INCLUDE */
+#include "i2c_gateway.h"
 
 /* USER CODE END INCLUDE */
 
@@ -259,11 +260,12 @@ static int8_t CDC_Control_FS(uint8_t cmd, uint8_t* pbuf, uint16_t length)
 static int8_t CDC_Receive_FS(uint8_t* Buf, uint32_t *Len)
 {
   /* USER CODE BEGIN 6 */
-  printf("Rx %d b\r\n", (int) *Len);
+
-  printf("Bytes: %.*s\r\n", (int) *Len, Buf);
+  i2c_command(Buf, *Len);
 
   USBD_CDC_SetRxBuffer(&hUsbDeviceFS, &Buf[0]);
   USBD_CDC_ReceivePacket(&hUsbDeviceFS);
+
   return (USBD_OK);
   /* USER CODE END 6 */
 }

USB_DEVICE/App/usbd_cdc_if.h

@@ -51,6 +51,7 @@
 #define APP_RX_DATA_SIZE  1000
 #define APP_TX_DATA_SIZE  1000
 /* USER CODE BEGIN EXPORTED_DEFINES */
+extern uint8_t UserTxBufferFS[APP_TX_DATA_SIZE];
 
 /* USER CODE END EXPORTED_DEFINES */
 

bluepill-i2c-gw.ioc

@@ -52,6 +52,8 @@ NVIC.BusFault_IRQn=true\:0\:0\:false\:false\:true\:false\:false\:false\:true
 NVIC.DebugMonitor_IRQn=true\:0\:0\:false\:false\:true\:false\:false\:false\:true
 NVIC.ForceEnableDMAVector=true
 NVIC.HardFault_IRQn=true\:0\:0\:false\:false\:true\:false\:false\:false\:true
+NVIC.I2C1_ER_IRQn=true\:5\:0\:false\:false\:true\:true\:true\:true\:true
+NVIC.I2C1_EV_IRQn=true\:5\:0\:false\:false\:true\:true\:true\:true\:true
 NVIC.MemoryManagement_IRQn=true\:0\:0\:false\:false\:true\:false\:false\:false\:true
 NVIC.NonMaskableInt_IRQn=true\:0\:0\:false\:false\:true\:false\:false\:false\:true
 NVIC.PendSV_IRQn=true\:15\:0\:false\:false\:false\:true\:false\:false\:true
@@ -148,7 +150,7 @@ USB_DEVICE.IPParameters=VirtualMode,VirtualModeFS,CLASS_NAME_FS,USBD_DEBUG_LEVEL
 USB_DEVICE.MANUFACTURER_STRING=VZLU
 USB_DEVICE.PID_CDC_FS=7717
 USB_DEVICE.PRODUCT_STRING_CDC_FS=VZLU I2C GW
-USB_DEVICE.USBD_DEBUG_LEVEL=2
+USB_DEVICE.USBD_DEBUG_LEVEL=0
 USB_DEVICE.VirtualMode=Cdc
 USB_DEVICE.VirtualModeFS=Cdc_FS
 VP_FREERTOS_VS_CMSIS_V2.Mode=CMSIS_V2