TM7707AD转换读取两个通道转换值时异常。

玉麒麟 · 发表于 2016-10-19 10:01:34

如题，写的STM32F103的TM7707驱动程序，现在只读取一个通道的转换值时正常，同时读取两个通道的时候读取不正确。请搞过的童鞋赐教。代码如下，GPIO和SPI初始化代码省略。
TM7707初始化。
void TM7707_Initialize(void)
{
      // Initialize GPIO for TM7707 device.
      TM7707_InitializeGPIO();
      // Initialize SPI controler.
      TM7707_InitializeSPI2();
      // Reset device(hardware).
      TM7707_Reset();
      // Synchronize device clock.
      TM7707_SynchronizeDeviceClock();
      // Self-calibration
      TM7707_SelfCalibration(CH_1, GAIN_1); // Channel 1 internal self-calibration.
      TM7707_SelfCalibration(CH_2, GAIN_1); // Channel 2 internal self-calibration.
      // Configure the clock registers
      TM7707_TransferByte(REG_CLOCK | WRITE | CH_1); // Write communication register to set clook register.
      TM7707_TransferByte(CLKDIS_0 | CLK_4_9152M | FS_50HZ); // External clock, frequency is 4.9152 MHz and the sampling frequency is 50Hz.
      TM7707_TransferByte(REG_CLOCK | WRITE | CH_2); // Write communication register to set clook register.
      TM7707_TransferByte(CLKDIS_0 | CLK_4_9152M | FS_50HZ); // External clock, frequency is 4.9152 MHz and the sampling frequency is 50Hz.
}

TM7707校准
void TM7707_SelfCalibration(uint8_t uiChannelIndex, uint8_t uiGain)
{
      uiChannelIndex = uiChannelIndex % CH_MAX;
      // ADC channel self-calibration
      TM7707_TransferByte(REG_SETUP | WRITE | uiChannelIndex); //Write communication register to set setup register.
      TM7707_TransferByte(MD_CAL_SELF | uiGain | UNIPOLAR | BUF_EN | FSYNC_0); //Write configuration register, start self-calibration.
      TM7707_WaitForDRDY(); // Wait for operation to complete(ablut 180ms).
      TM7707_TransferByte(REG_SETUP | WRITE | uiChannelIndex); //Write communication register to set setup register.
      TM7707_TransferByte(MD_NORMAL | uiGain | UNIPOLAR | BUF_EN | FSYNC_0); //Write configuration register, start self-calibration.
      TM7707_WaitForDRDY();
}

硬件复位
void TM7707_Reset(void)
{
      TM7707_ST_RESET();
      TM7707_Delay(5000);
      TM7707_ST_UNRESET();
      TM7707_Delay(1000);
}

时钟同步
void TM7707_SynchronizeDeviceClock(void)
{
      uint8_t i;
      // Keep SCLK pin high at 40 cycles.
      for(i=0; i<5; i++)
      {
         TM7707_TransferByte(0xFF);
      }
}

读取转换值
uint32_t TM7707_ReadADCValue(uint8_t uiChannelIndex)
{
      uint32_t rtnADValue;

      rtnADValue = 0x00000000;
      // Wait for the conversion to complete
      TM7707_WaitForDRDY();
      // Write channel index.
      TM7707_TransferByte(REG_DATA | READ | uiChannelIndex);
      // Read ADC value.
      TM7707_CS_ENABLE();
      rtnADValue |= TM7707_TransferByte(0xFF);
      rtnADValue <<= 8;
      rtnADValue |= TM7707_TransferByte(0xFF);
      rtnADValue <<= 8;
      rtnADValue |= TM7707_TransferByte(0xFF);
      TM7707_CS_DISABLE();

      return rtnADValue;
}

主入口
int main(void)
{
      uint32_t auiADCValue[2] = {0};
      float auiVoltage[2] = {0};

      HSEClocks_Initialize(RCC_PLLMul_9);
      NVIC_Initialize(NVIC_PriorityGroup_2);
      DebugPort_Initialize(DEBUG_SWD);
      Initialize_Systick(72, TRUE);

      DebugSerialPort_Initialize(9600);

      TM7707_Initialize();
      TM7707_SelfCalibration(CH_1, GAIN_1);
      TM7707_SelfCalibration(CH_2, GAIN_1);

      while(1)
      {
         // Read adc value.
         auiADCValue[0] = TM7707_ReadADCValue(CH_1);
         auiVoltage[0] = 5.0*auiADCValue[0]/16777216;
         auiADCValue[1] = TM7707_ReadADCValue(CH_2);
         auiVoltage[1] = 5.0*auiADCValue[1]/16777216;

         // Print adc value to serial.
         // Format as ADvalue:Voltage:Reference
         printf("CH1:%10u, Voltage:%1.6f  |  CH2:%10u, Voltage:%1.6f\r\n", auiADCValue[0], auiVoltage[0], auiADCValue[1], auiVoltage[1]);
      }
}

附件为MDK5完整工程，STM32F103ZET6，使用SPI2，72MHz，64分频。

STM32F1_TM7707.zip (310.89 KB, 下载次数: 449)

玉麒麟 · 发表于 2016-10-19 10:01:35

已找到原因，很低级的错误，DRDY位判断错了。

但是发现一个新的问题，这个驱动是用TM7705的驱动程序改造而来，而根据官方的数据手册，TM7705和7707的寄存器定义并不相同，比如，7707是没有时钟寄存器的，但是有滤波数据寄存器。
但关键问题是，我按照7707数据手册操作芯片，程序乱跑，读出来的不知道啥数，但是按照7705就好用，真是费解………………