working but needs verifi

sht30_driver.c

@@ -2,7 +2,144 @@
  * sht30_driver.c
  *
  *  Created on: 30. apr. 2025
- *      Author: Chris
+ *      Author: Christian L. V. Madsen (OZ1CM)
  */
+ #include "sht30_driver.h"
+ 
+#define REV16_A(X) (((X) << 8) | ((X)>>8))
+#define REV8_A(X) (((X) << 4) | ((X)>>4))
+
+static int isStructOk(SHT30_Struct_Type *inst){
+	
+	if(inst == NULL)return 0;
+	if(inst->i2c_transfer_inst == NULL)return 0;
+	if(inst->i2c_transfer_evt == NULL)return 0;
+	
+	return 1;
+}
+
+uint8_t crc8_i2c_u16(uint16_t input) {
+    uint8_t crc = 0xFF;
+    uint8_t poly = 0x31;
+
+    // Process MSB first (big endian)
+    for (int i = 1; i >= 0; i--) {
+        uint8_t byte = (input >> (8 * i)) & 0xFF;
+        crc ^= byte;
+
+        for (uint8_t j = 0; j < 8; j++) {
+            if (crc & 0x80)
+                crc = (crc << 1) ^ poly;
+            else
+                crc <<= 1;
+        }
+    }
+
+    return crc;  // Final XOR is 0x00, so this is the final CRC
+    
+}
+static int readRegister(SHT30_Struct_Type *inst, uint8_t *data_addr, uint8_t *data, uint32_t len){
+
+	// Write what kind of addr we would like to read from:
+	int ret = inst->i2c_transfer_evt(inst->i2c_transfer_inst,data_addr,2, SHT30_I2C_SET);
+
+	// Read data:
+	ret += inst->i2c_transfer_evt(inst->i2c_transfer_inst,data,len, SHT30_I2C_GET);
+
+	return ret;
+}
+
+static int writeRegister(SHT30_Struct_Type *inst, uint16_t data_addr, uint8_t *data, uint32_t len){
+
+	// Write what kind of addr we would like to read from:
+	inst->i2c_transfer_evt(inst->i2c_transfer_inst,(uint8_t *)&data_addr,2, SHT30_I2C_SET);
+
+	// Write data:
+	inst->i2c_transfer_evt(inst->i2c_transfer_inst,data,len, SHT30_I2C_SET);
+
+	return 0;
+}
+
+int sht30_writeCmd(SHT30_Struct_Type *inst, uint16_t command){
+	
+	if(!isStructOk(inst))return 1;
+	
+	int ret;
+	uint8_t buffer[2] = {0};
+	buffer[0] = (command >> 8) & 0xff;
+	buffer[1] = (command & 0xff);
+	ret = inst->i2c_transfer_evt(inst->i2c_transfer_inst,buffer,sizeof(buffer), SHT30_I2C_SET);
+	
+	
+	return ret;
+	
+}
+ 
+static int SHT30_resetConnection(SHT30_Struct_Type *inst){
+	
+	if(!isStructOk(inst))return 1;
+
+	for(int i = 0; i< 3; i++){
+		int ret = 0;
+
+		ret = sht30_writeCmd(inst,0x30A2); // Soft reset device
+		ret = sht30_writeCmd(inst,0x272A); // Measurement Command for Periodic Data Acquisition Mode
+		if(ret == 0){
+			return 0;
+		}
+		
+	}
+	
+	return 1;
+
+}
+
+void SHT30_calcRawData(SHT30_Struct_Type *p){
 
 
+	p->Message.RawTemp = REV16_A(p->Message.RawTemp);
+	p->Message.RawHumidity = REV16_A(p->Message.RawHumidity);
+	
+	if(crc8_i2c_u16(p->Message.RawTemp) != p->Message.CRC_Temp) return;
+	if(crc8_i2c_u16(p->Message.RawHumidity) != p->Message.CRC_Humidity) return;
+
+	// Calc Temperature
+	p->Temperature_mC = p->Message.RawTemp * 17500;
+	p->Temperature_mC = p->Temperature_mC >> 16;
+	p->Temperature_mC -= 4500;
+
+	// Calc Humidity
+	p->Humidity = p->Message.RawHumidity * 100;
+	p->Humidity = p->Humidity >> 16;
+
+}
+ 
+ void sht30_ReadData(SHT30_Struct_Type *inst){
+		int ret;
+		uint8_t reg[2] = {0xe0,0x00};
+		ret = readRegister(inst, reg, (void*)&inst->Message, sizeof(SHT30_Message_Type));
+
+		if(ret != 0){
+			SHT30_resetConnection(inst);
+
+		}else{
+			SHT30_calcRawData(inst);
+		}
+
+
+
+}
+
+int sht30_init(SHT30_Struct_Type *inst, void *i2c_transfer_inst, setGet_I2C_Event_fpt i2c_transfer_evt){
+	if(inst == NULL)return -1;
+	if(i2c_transfer_inst == NULL)return -1;
+	if(i2c_transfer_evt == NULL)return -1;
+	
+	inst->i2c_transfer_inst = i2c_transfer_inst;
+	inst->i2c_transfer_evt = i2c_transfer_evt;
+	
+	//SHT30_resetConnection(inst);
+	
+	return 0;
+
+}

sht30_driver.h

@@ -7,11 +7,42 @@
 
 #ifndef MAIN_SHT30_DRIVER_SHT30_DRIVER_H_
 #define MAIN_SHT30_DRIVER_SHT30_DRIVER_H_
+#include "stdio.h"
+#include <stdint.h>
 
-typedef struct {
+enum{
+	SHT30_I2C_GET = 0,
+	SHT30_I2C_SET = 1,
+
+};
+
+typedef int (*setGet_I2C_Event_fpt)(void *inst, uint8_t *data, uint32_t len, uint8_t set_get);
+
+typedef struct SHT30_Message{
+    uint16_t RawTemp;
+    uint8_t CRC_Temp;
+    uint16_t RawHumidity;
+    uint8_t CRC_Humidity;
 
 
+}__attribute__((packed)) SHT30_Message_Type;
 
-}sht30_registers_t;
+typedef struct SHT30_Struct
+{
+	// I2C interface
+	void *i2c_transfer_inst;
+	setGet_I2C_Event_fpt i2c_transfer_evt;
+	
+    // Data
+    SHT30_Message_Type Message;
+    int32_t Temperature_mC;
+    uint32_t Humidity;
+
+} __attribute__((packed)) SHT30_Struct_Type;
+
+
+int sht30_init(SHT30_Struct_Type *inst, void *i2c_transfer_inst, setGet_I2C_Event_fpt i2c_transfer_evt);
+void sht30_ReadData(SHT30_Struct_Type *p);
+uint8_t crc8_i2c_u16(uint16_t input);
 
 #endif /* MAIN_SHT30_DRIVER_SHT30_DRIVER_H_ */