Not recieving data via SPI on ESP-wroom-32 from Teensy 4.1
Posted: Sun Jun 23, 2024 3:28 am
At the very least I am sending the letter "C" from the Teensy to the ESP-wroom-32.
ESP says its receiving a null. I'm stumped. The reason for the 2 sec delay on the esp32, I was just trying to see if it recognized the pin being flipped from low to high on each side (it does).
Teensy code:
ESP code:
ESP says its receiving a null. I'm stumped. The reason for the 2 sec delay on the esp32, I was just trying to see if it recognized the pin being flipped from low to high on each side (it does).
Teensy code:
Code: Select all
#include <Arduino.h>
#include <SPI.h>
const int slaveSelectPin = 40; // CS pin
const int readyPin = 9; // Ready pin
void setup() {
Serial.begin(115200);
SPI.begin(); // Initialize SPI
pinMode(slaveSelectPin, OUTPUT);
pinMode(readyPin, INPUT); // Set ready pin as input
digitalWrite(slaveSelectPin, HIGH);
Serial.println("Teensy 4.1: SPI communication test started");
}
void loop() {
// Wait until the ready pin is HIGH
if (digitalRead(readyPin) == HIGH) {
Serial.println("ESP32 is ready to receive data.");
char data = 'C'; // Data to send to ESP32
Serial.println("Sending: " + String(data));
SPI.beginTransaction(SPISettings(1000000, MSBFIRST, SPI_MODE0));
digitalWrite(slaveSelectPin, LOW); // Select the slave
SPI.transfer(data); // Send data
digitalWrite(slaveSelectPin, HIGH); // Deselect the slave
SPI.endTransaction();
} else {
Serial.println("ESP32 is not ready.");
}
delay(1000); // Wait for a second before checking again
}ESP code:
Code: Select all
#include <Arduino.h>
#include <SPI.h>
const int slaveSelectPin = 5; // CS pin
const int readyPin = 33; // Ready pin
volatile bool dataReceived = false;
volatile char receivedData = 0;
void IRAM_ATTR onSPI() {
dataReceived = true;
}
void setup() {
Serial.begin(115200);
pinMode(slaveSelectPin, INPUT_PULLUP);
pinMode(readyPin, OUTPUT); // Set ready pin as output
digitalWrite(readyPin, LOW); // Initially set ready pin to LOW
SPI.begin(18, 23, 19, slaveSelectPin); // Initialize SPI with SCK, MISO, MOSI, and SS
attachInterrupt(digitalPinToInterrupt(slaveSelectPin), onSPI, FALLING);
Serial.println("ESP32: SPI communication test started");
}
void loop() {
if (dataReceived) {
SPI.beginTransaction(SPISettings(1000000, MSBFIRST, SPI_MODE0));
receivedData = SPI.transfer(0x00); // Read data from master
SPI.endTransaction();
Serial.print("Received from Teensy: ");
Serial.println(receivedData, DEC); // Print the received data as a number
Serial.print("Character: ");
Serial.println(receivedData); // Print the received data as a character
dataReceived = false;
digitalWrite(readyPin, LOW); // Set ready pin to LOW after receiving data
delay(2000);
} else {
digitalWrite(readyPin, HIGH); // Set ready pin to HIGH when ready to receive data
}
}