Hi,@Rene Lenerve
I have checked my code and the data I read is 1023.75. According to the code, the output data is because the sensor is not detected, so I think there may be a hardware connection problem. Please help me check whether STM32L476 should be connected in this way？
#include"MAX6675.h"
SPI_HandleTypeDef hspi2;
#define MAX6675_CS_Pin GPIO_PIN_12
#define MAX6675_CS_GPIO_Port GPIOB
float K_Temperature ; //K型热电�?� 温度值
char temperaturebuffer[30] = { 0xD1, 0x01, 0x1B, 0x54, 0x02, 0x65, 0x6E };
// ------------------- Functions ----------------
uint8_t MAX6675_ReadWriteByte(uint8_t txData)
{
unsigned char txdata,rxdata;
txdata = txData;
HAL_SPI_TransmitReceive(&hspi2,&txdata,&rxdata,2,1000);
return rxdata;
}
//MAX6675 片选控制
void MAX6675_CS(unsigned char choose)
{
if(choose == 1)
{
HAL_GPIO_WritePin(GPIOB, GPIO_PIN_12, GPIO_PIN_SET);
}
else
{
HAL_GPIO_WritePin(GPIOB, GPIO_PIN_12, GPIO_PIN_RESET);
}
}
/**
* @brief max6675模�?�读�?�测得的原始数�?�
* @param None
* @retval 温度的原始数�?�
*/
uint16_t MAX6675_ReadRawValue(void)
{
uint16_t tmp=0;
MAX6675_CS(0);
tmp = MAX6675_ReadWriteByte(0XFF); //read MSB
tmp <<= 8;
tmp |= MAX6675_ReadWriteByte(0XFF); //read LSB
MAX6675_CS(1);
if (tmp & 4)
{
// thermocouple open
tmp = 4095; //未检测到热电�?�
}
else
{
tmp = tmp >> 3;
tmp &= 0x0FFF; // �?留低 12 �?数�?�
}
return tmp;
}
/**
* @brief max6675模�?�读�?�温度
* @param None
* @retval 温度值（�?��?：℃）
*/
float MAX6675_ReadTemperature(void)
{
return (MAX6675_ReadRawValue() * 1024.0 / 4096);
}
/* write text message to EEPROM */
HAL_Delay(500);
K_Temperature=MAX6675_ReadTemperature(); //读�?�热电�?�温度值
sprintf(&temperaturebuffer[7], "Temperature = %.2f", K_Temperature);
NfcTag_WriteNDEF(sizeof(temperaturebuffer) + 1, (uint8_t *)temperaturebuffer);
/* Set the LED3 on to indicate Programing done */
NFC07A1_LED_On( YELLOW_LED );
Hi,@Rene Lenerve
I changed my code as you instructed，but I still failed. Here are my codes，I think the temperature is not measured and the 12-digit data is 1, and the current data should be caused by incorrect reading of digits. Please help me to check it，I don't know why I got 969.
static void MX_SPI2_Init(void)
{
/* SPI2 parameter configuration*/
hspi2.Instance = SPI2;
hspi2.Init.Mode = SPI_MODE_MASTER;
hspi2.Init.Direction = SPI_DIRECTION_2LINES;
hspi2.Init.DataSize = SPI_DATASIZE_16BIT;
hspi2.Init.CLKPolarity = SPI_POLARITY_LOW;
hspi2.Init.CLKPhase = SPI_PHASE_1EDGE;
hspi2.Init.NSS = SPI_NSS_SOFT;
hspi2.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_128;
hspi2.Init.FirstBit = SPI_FIRSTBIT_MSB;
hspi2.Init.TIMode = SPI_TIMODE_DISABLE;
hspi2.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
hspi2.Init.CRCPolynomial = 10;
if (HAL_SPI_Init(&hspi2) != HAL_OK)
{
Error_Handler();
}
}
HAL_GPIO_WritePin(GPIOB, GPIO_PIN_12, GPIO_PIN_SET);
/*引脚�?置 */
GPIO_InitStruct.Pin = GPIO_PIN_12;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
#include"MAX6675.h"
SPI_HandleTypeDef hspi2;
#define MAX6675_CS_Pin GPIO_PIN_12
#define MAX6675_CS_GPIO_Port GPIOB
// ------------------- Functions ----------------
uint16_t MAX6675_ReadByte(void)
{
unsigned char rxdata[2]; //Warning: 2 bytes are read because hspi2.Init.DataSize = SPI_DATASIZE_16BIT;
uint16_t readtemperature;
HAL_SPI_Receive(&hspi2,rxdata,1,1000);
readtemperature = rxdata[0];
readtemperature = (readtemperature << 8) | rxdata[1];
return readtemperature ;
}
//MAX6675 片选控制
void MAX6675_CS(unsigned char choose)
{
if(choose == 1)
{
HAL_GPIO_WritePin(GPIOB, GPIO_PIN_12, GPIO_PIN_SET);
}
else
{
HAL_GPIO_WritePin(GPIOB, GPIO_PIN_12, GPIO_PIN_RESET);
}
}
/**
* @brief max6675模�?�读�?�测得的原始数�?�
* @param None
* @retval 温度的原始数�?�
*/
uint16_t MAX6675_ReadRawValue(void)
{
uint16_t tmp=0;
MAX6675_CS(0);
tmp = MAX6675_ReadByte();
MAX6675_CS(1);
if (tmp & 4)
{
// thermocouple open
tmp = 4095; //未检测到热电�?�
}
else
{
tmp = tmp >> 3;
tmp &= 0x0FFF; // �?留低 12 �?数�?�
}
return tmp;
}
/**
* @brief max6675模�?�读�?�温度
* @param None
* @retval 温度值（�?��?：℃）
*/
float MAX6675_ReadTemperature(void)
{
return (MAX6675_ReadRawValue() * 1024.0 / 4096);
}
