From a3939b6f9a6ccc263aa1efb6ed6ae2d74d2efce0 Mon Sep 17 00:00:00 2001
From: Andreas Berthoud <andreasberthoud@gmail.com>
Date: Fri, 18 Jun 2021 23:54:37 +0200
Subject: [PATCH] i2c: load and interprete moisture value from seesaw

---
 nucleo-wb55-i2c/Core/Src/main.c | 113 ++++++++++++++++++++++++--------
 1 file changed, 87 insertions(+), 26 deletions(-)

diff --git a/nucleo-wb55-i2c/Core/Src/main.c b/nucleo-wb55-i2c/Core/Src/main.c
index 625bc1a..02f7d3b 100644
--- a/nucleo-wb55-i2c/Core/Src/main.c
+++ b/nucleo-wb55-i2c/Core/Src/main.c
@@ -59,6 +59,31 @@ static void MX_I2C1_Init(void);
 
 /* Private user code ---------------------------------------------------------*/
 /* USER CODE BEGIN 0 */
+
+#define SEESAW_REGISTER_LEN             (2)
+#define SEESAW_TEMPERATURE_BUFFER_LEN   (4)
+#define SEESAW_MOISTURE_BUFFER_LEN      (2)
+
+#define SEESAW_STATUS_BASE              (0x00)
+#define SEESAW_TOUCH_BASE               (0x0F)
+#define SEESAW_STATUS_TEMP              (0x04)
+#define SEESAW_TOUCH_CHANNEL_OFFSET     (0x10)
+
+typedef uint8_t seesaw_register_t[SEESAW_REGISTER_LEN];
+
+typedef struct seesaw_board {
+  int temperature_i2c_timeout;
+  int temperature_write_read_timeout;
+  int moisture_i2c_timeout;
+  int moisture_write_read_timeout;
+  int address;
+  uint8_t temperature_buffer[SEESAW_TEMPERATURE_BUFFER_LEN];
+  uint8_t moisture_buffer[SEESAW_MOISTURE_BUFFER_LEN];
+} seesaw_board_t;
+
+const seesaw_register_t temperature_register = {SEESAW_STATUS_BASE, SEESAW_STATUS_TEMP};
+const seesaw_register_t moisture_register = {SEESAW_TOUCH_BASE, SEESAW_TOUCH_CHANNEL_OFFSET};
+
 HAL_StatusTypeDef i2c_write(uint16_t DevAddress, uint8_t *pData, uint16_t Size, uint32_t Timeout) {
   //printf("I2C WRITE | address=0x%04x | size=0x%04x\n", DevAddress, Size);
   return HAL_I2C_Master_Transmit(&hi2c1, DevAddress, pData, Size, Timeout);
@@ -69,11 +94,44 @@ HAL_StatusTypeDef i2c_read(uint16_t DevAddress, uint8_t *pData, uint16_t Size, u
   return HAL_I2C_Master_Receive(&hi2c1, DevAddress, pData, Size, Timeout);
 }
 
+HAL_StatusTypeDef seesaw_read(
+  int address,
+  seesaw_register_t seesaw_register,
+  uint8_t * buffer,
+  int i2c_timeout,
+  int write_read_timeout
+) {
+  HAL_StatusTypeDef i2c_status;
+  i2c_status = i2c_write(
+    address, 
+    seesaw_register, 
+    SEESAW_REGISTER_LEN, 
+    i2c_timeout
+  );
+  if (i2c_status != HAL_OK) { return i2c_status; }
+
+  HAL_Delay(write_read_timeout);
+
+  i2c_status = i2c_read(
+    address, 
+    buffer, 
+    SEESAW_TEMPERATURE_BUFFER_LEN, 
+    i2c_timeout
+  );
+  if (i2c_status != HAL_OK) { return i2c_status; }
+
+  return HAL_OK;
+}
+
 float getTemp(uint8_t * buf) {
   int32_t ret = ((uint32_t)buf[0] << 24) | ((uint32_t)buf[1] << 16) |
                 ((uint32_t)buf[2] << 8) | (uint32_t)buf[3];
   return (1.0 / (1UL << 16)) * ret;
 }
+
+int getMoisture(uint8_t * buf) {
+  return ((uint16_t)buf[0] << 8) | buf[1];
+}
 /* USER CODE END 0 */
 
 /**
@@ -118,43 +176,46 @@ int main(void)
 
   /* Infinite loop */
   /* USER CODE BEGIN WHILE */
-  int index = 0;
+
+  /* I2C config */
+  const seesaw_board_t seesaw_board = {
+    .temperature_i2c_timeout = 1000,
+    .temperature_write_read_timeout = 100,
+    .moisture_i2c_timeout = 3000,
+    .moisture_write_read_timeout = 100,
+    .address = 0x36 << 1, // shift by one because it is a 7bit address
+  };
+
   HAL_StatusTypeDef i2c_status;
-  int ADAFRUIT_ADDR = 0x36 << 1;
-  const int BUF_LEN = 4;
-  uint8_t buf[BUF_LEN];
-  uint8_t prefix[2];
-  prefix[0] = 0x0;
-  prefix[1] = 0x4;
+
+  printf("\n\n\nHoi, da bini wieder\n");
 
   while (1)
   {
-  	//printf("test %d\n\r", index++);
-    //HAL_Delay(100);
-
-    HAL_Delay(10);
 
-    i2c_status = i2c_write(ADAFRUIT_ADDR, prefix, 2, 1000);
+    i2c_status = seesaw_read(
+      seesaw_board.address,
+      temperature_register,
+      seesaw_board.temperature_buffer,
+      seesaw_board.temperature_i2c_timeout,
+      seesaw_board.temperature_write_read_timeout
+    );
     if (i2c_status != HAL_OK) {
-      printf("ERROR: %d\n", (int)i2c_status);
       Error_Handler();
     }
-
-    HAL_Delay(100);
-
-    i2c_status = i2c_read(ADAFRUIT_ADDR, buf, BUF_LEN, 1000);
+    printf("Temperature: %2.2f degree celsius | ", getTemp(seesaw_board.temperature_buffer));
+
+    i2c_status = seesaw_read(
+      seesaw_board.address,
+      moisture_register,
+      seesaw_board.moisture_buffer,
+      seesaw_board.moisture_i2c_timeout,
+      seesaw_board.moisture_write_read_timeout
+    );
     if (i2c_status != HAL_OK) {
-      printf("ERROR: %d\n", (int)i2c_status);
       Error_Handler();
     }
-
-    //printf("Buffer: ");
-    for (int i = 0; i < BUF_LEN; i++) {
-      //printf("%d ", buf[i]);
-    }
-    //printf("\n");
-    
-    printf("Temperature: %2.2f degree celsius\n", getTemp(buf));
+    printf("Moisture value: %d\n", getMoisture(seesaw_board.moisture_buffer));
 
     /* USER CODE END WHILE */