前段时间一直在做一个MAX31865+PT100的测试，在淘宝买了一个模块，调试了很久，一直没有调试通，昨天晚上在家的时候一直在找问题，终于在今天晚上完成了调试，所以写个分享和大家说一下进度。
淘宝上的模块有点坑，本来是可以选择焊接的，但是说巧不巧，调试的时候通过错误状态寄存器发现了提示RTD+短路到GND，导致数据一直读取不出来来，而错误位一直提示错误，导致读取到的数据一直为0，经过排查，是网上后买的模块本生存在短路导致的，用小刀隔开之后就正常了，下面先上个图。由于一直在调试这个SPI，所以其他的都还没有做测试，这里就直接放仿真的图来。
好了，下面放一部分代码上来，以及自己搜集的资料。希望能够给大家一些帮助。
- #include "MAX_31865.h"
- #include "DRV_SPI.h"
- void LEDIO_Init(void)
- {
- GPIO_Config_T configStruct;
- RCM_EnableAPB2PeriphClock(RCM_APB2_PERIPH_GPIOE);
- configStruct.pin =GPIO_PIN_6;
- configStruct.mode = GPIO_MODE_OUT_PP;
- configStruct.speed = GPIO_SPEED_50MHz;
- GPIO_Config(GPIOE, &configStruct);
- }
- void LED_Flash(void)
- {
- GPIO_ResetBit(GPIOE,GPIO_PIN_6);
- Delay(500);
- GPIO_SetBit(GPIOE,GPIO_PIN_6);
- Delay(500);
- }
- float DataTemp=0;
- unsigned char REG_ADD0=0,FaultStatus=0;
- int main(void)
- {
- LEDIO_Init();
- Delay(10);
- MAX_31865_Init(MAX31865_3WIRE);
- Delay(10);
- while (1)
- {
- DataTemp=MAX_31865_Test();
- LED_Flash();
- FaultStatus=ReadFaultREG();
- }
- }
- #include "DRV_SPI.h"
- /*
- =====================================
- SPI_CS---->PB12
- SPI_SCLK-->PB13
- SPI_MISO-->PB14
- SPI_MOSI-->PB15
- =====================================
- */
- void SPI_FullDuplex_Init(void)
- {
- GPIO_Config_T gpioConfig;
- SPI_Config_T spiConfig;
- /* Enable related Clock */
- RCM_EnableAPB1PeriphClock(RCM_APB1_PERIPH_SPI2);
-
- RCM_EnableAPB2PeriphClock(RCM_APB2_PERIPH_GPIOB);
- /* config PIN_6 MISO */
- gpioConfig.pin = GPIO_PIN_14 ;
- gpioConfig.mode = GPIO_MODE_IN_FLOATING;
- gpioConfig.speed = GPIO_SPEED_50MHz;
- GPIO_Config(GPIOB, &gpioConfig);
- /* config PIN_5->SCK , PIN_7->MOSI */
- gpioConfig.pin = GPIO_PIN_13 | GPIO_PIN_15;
- gpioConfig.mode = GPIO_MODE_AF_PP;
- gpioConfig.speed = GPIO_SPEED_50MHz;
- GPIO_Config(GPIOB, &gpioConfig);
- /* config PIN_6 cs */
- gpioConfig.pin = GPIO_PIN_12 ;
- gpioConfig.mode = GPIO_MODE_OUT_PP;
- gpioConfig.speed = GPIO_SPEED_50MHz;
- GPIO_Config(GPIOB, &gpioConfig);
-
-
-
- SPI_ConfigStructInit(&spiConfig);
- spiConfig.length = SPI_DATA_LENGTH_8B;
- spiConfig.baudrateDiv = SPI_BAUDRATE_DIV_64;
- /* 2 line full duplex */
- spiConfig.direction = SPI_DIRECTION_2LINES_FULLDUPLEX;
- /* LSB first */
- spiConfig.firstBit = SPI_FIRSTBIT_MSB;
- /* Slave mode */
- spiConfig.mode = SPI_MODE_MASTER;
- /* Polarity is low */
- spiConfig.polarity = SPI_CLKPOL_LOW;
- /* Software select slave enable */
- spiConfig.nss = SPI_NSS_SOFT;
- /* Phase is 1 edge */
- spiConfig.phase = SPI_CLKPHA_2EDGE;
- /* SPI config */
- SPI_Config(SPI2, &spiConfig);
- SPI_ConfigDataSize(SPI2, SPI_DATA_LENGTH_8B);
- SPI_Enable(SPI2);
- SPI_CS_HIGH();
-
- }
- void SPI_WriteByte(unsigned char Data)
- {
- while (SPI_I2S_ReadStatusFlag(SPI2, SPI_FLAG_BSY) != RESET){};
- SPI_I2S_TxData(SPI2, Data);
- }
- unsigned char SPI_ReadByte(void)
- {
- unsigned char Data=0;
- Data = SPI_I2S_RxData(SPI2);
- while (SPI_I2S_ReadStatusFlag(SPI2, SPI_FLAG_RXBNE) != RESET);
- return Data;
- }
- unsigned char SPI_Read_Write(unsigned char Data)
- {
- unsigned char RTNData=0;
- while (SPI_I2S_ReadStatusFlag(SPI2, SPI_FLAG_TXBE) == RESET){};
- SPI_I2S_TxData(SPI2, Data);
- while(SPI_I2S_ReadStatusFlag(SPI2, SPI_FLAG_RXBNE) == RESET){};
- RTNData = SPI_I2S_RxData(SPI2);
- return RTNData;
- }
- float MAX31865_ReadTemp(float RTDnominal, float RefResistor)
- {
- float Z1, Z2, Z3, Z4, Rt, temp;
- float rpoly = Rt;
- Rt = MAX31865_ReadRTD();
- Rt /= 32768.0;
- Rt *= RefResistor;
-
- Z1 = -RTD_A;
- Z2 = RTD_A * RTD_A - (4.0 * RTD_B);
- Z3 = (4.0 * RTD_B) / RTDnominal;
- Z4 = 2.0 * RTD_B;
- temp = Z2 + (Z3 * Rt);
- temp = (sqrt(temp) + Z1) / Z4;
- if (temp >= 0)
- return temp;
- // ugh.
- Rt /= RTDnominal;
- Rt *= 100.0; // normalize to 100 ohm
- temp = -242.02;
- temp += 2.2228 * rpoly;
- rpoly *= Rt; // square
- temp += 2.5859e-3 * rpoly;
- rpoly *= Rt; // ^3
- temp -= 4.8260e-6 * rpoly;
- rpoly *= Rt; // ^4
- temp -= 2.8183e-8 * rpoly;
- rpoly *= Rt; // ^5
- temp += 1.5243e-10 * rpoly;
- return temp;
- }
- float MAX_31865_Test(void)
- {
- float TempData=0.0;
- TempData=MAX31865_ReadTemp(RTD_NNUM,REG_REF);
- Delay(10);
- return TempData;
- }
max31865.rar
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