[参考译文] ADS1298：SPI 通信出现故障

尊敬的 Abdelrahman：

感谢您发帖。 您能否共享读取器件 ID 寄存器的 SPI 帧的逻辑分析仪捕获结果？  

此致、

Ryan

您好、Ryan、  

我调整了 SPI 配置、现在、当 nCS 处于低电平时、调整了 SCLK。 此外、我能够使用 MOSI 发送命令、但 MISO 上没有活动。 我上传了一个 zip 文件夹中的逻辑分析仪图像+代码。 如果您能为我提供进一步的指导、我将不胜感激。  

#include <SPI.h>

// Define the SPI pins for HSPI (on ESP32 or custom setup)
#define HSPI_MISO   12
#define HSPI_MOSI   13
#define HSPI_SCLK   14
#define HSPI_SS     15
#define PWDN_PIN    32  // Define the PWDN control pin for ADS1298

static const int spiClk = 150000; // 150 kHz clock speed

// Uninitialized pointer to SPI object
SPIClass *hspi = NULL;

void setup() {
  // Initialize serial for debugging
  Serial.begin(115200);
  
  // Initialize instance of the SPIClass attached to HSPI
  hspi = new SPIClass(HSPI);

  // Initialize SPI bus with default pins SCLK = 14, MISO = 12, MOSI = 13, SS = 15
  hspi->begin(HSPI_SCLK, HSPI_MISO, HSPI_MOSI, HSPI_SS);

  // Set SS as output and set it high to start with (deselect)
  pinMode(HSPI_SS, OUTPUT);
  digitalWrite(HSPI_SS, HIGH);

  // Set up the PWDN control pin
  pinMode(PWDN_PIN, OUTPUT);

  // Power up the ADS1298 by setting PWDN pin HIGH
  digitalWrite(PWDN_PIN, HIGH);
  delay(100);  // Small delay to ensure the device powers up

  Serial.println("ADS1298 Powered Up");
}

void loop() {
  // Optionally: Add logic to enter Power-Down mode (if needed)
  // digitalWrite(PWDN_PIN, LOW);  // Pull LOW to enter Power-Down mode
  // delay(1000);  // Delay to simulate Power-Down mode

  byte commands[] = {0x0A, 0x20, 0x00};  // Array of commands
  byte response;                         // Variable to hold the response from the slave
  byte deviceID = 0x00;                  // Device ID

  // Start SPI transaction for sending the commands
  hspi->beginTransaction(SPISettings(spiClk, MSBFIRST, SPI_MODE1));

  // Pull SS low to select the slave
  digitalWrite(HSPI_SS, LOW);
  delayMicroseconds(10);  // Small delay to stabilize the signal
  
  // Send the command bytes to the slave
  for (int i = 0; i < sizeof(commands) / sizeof(commands[0]); i++) {
    response = hspi->transfer(commands[i]);  // Send and receive at the same time
    Serial.print("Sent command: ");
    Serial.println(commands[i], HEX);
    Serial.print("Response from slave: ");
    Serial.println(response, HEX);  // Display the response (if the slave sends any data back)
  }

  // Send and receive device ID
  response = hspi->transfer(deviceID);  // Send and receive at the same time
  Serial.print("Sent device ID command: ");
  Serial.println(deviceID, HEX);
  
  Serial.print("Response from slave: ");
  Serial.println(response, HEX);  // Display the response (if the slave sends any data back)

  // Pull SS high to deselect the slave
  digitalWrite(HSPI_SS, HIGH);

  // End SPI transaction
  hspi->endTransaction();

  delay(1000); // Wait for a second before the next loop
}

尊敬的 Abdelrahman：

在该帧中、您将发送停止命令0Ah。 但是、这仅用于停止 ADC 转换。 这就是在您为后面的 RREG 命令发送额外的 SCLK 时没有 nDRDY 或 DOUT 活动的原因。

顺便说一下-为了发送 RREG 命令0x20 0x00、您必须首先发送 SDATAC (11h)(即"停止 RDATAC")。 这与停止命令(0Ah)不同、停止命令仅用于控制 ADC 转换。 可以理解的是、这可能造成了一些混淆。  

此致、

Ryan