Good day!
With the use of multiple MCP2515 boards I am trying to make a CAN network for my model railroad. The purpose of this network is relaying all information to a single ESP8266 module for making it possible to make it available online.
I'm currently at a block, and cannot figure out what is wrong:
I have 2 nano's with each a rotary encoder with the NewEncoder library. The clock pins is connected to D2 and the data pin to D3. These both work, as confirmed by reading the encoder values from the serial monitor.
Together with this each nano is connected to a canbus module (see link to board in first paragraph). These modules are connected accordingly:
INT D2, SCK D13, SI D11, SO D12, CS D10
A third canbus module is connected to a Nodemcu esp8266 as follows:
INT D4, SCK D5, SI D7, SO D6, CS D3
The can bus modules High and Low are connected with the end resistors in place where required.
Code on both nano's:
#include <NewEncoder.h>
#include <SPI.h>
#include <mcp2515.h>
struct can_frame canMsg;
MCP2515 mcp2515(10);
// Rotary Encoder
#define CLK 2
#define DT 3
#define SW 4
const int minVal = -30;
const int maxVal = 30;
const int startVal = 0;
int16_t currentValue;
int16_t prevEncoderValue;
unsigned long lastButtonPress = 0;
NewEncoder myEncoderObject(CLK, DT, minVal, maxVal, startVal, FULL_PULSE);
void setup() {
NewEncoder::EncoderState myEncState;
Serial.begin(115200);
SPI.begin();
mcp2515.reset();
mcp2515.setBitrate(CAN_500KBPS, MCP_8MHZ);
mcp2515.setNormalMode();
if (!myEncoderObject.begin()) {
Serial.println("Encoder Failed to Start. Check pin assignments and available interrupts. Aborting.");
while (1) {
yield();
}
}
else {
// store values of currentValue and EncoderClick into variable myEncState
myEncoderObject.getState(myEncState);
Serial.print("Encoder Successfully Started at value = ");
prevEncoderValue = myEncState.currentValue;
Serial.println(prevEncoderValue);
}
}
void loop() {
NewEncoder::EncoderState myCurrentEncoderState;
if (myEncoderObject.getState(myCurrentEncoderState)) {
Serial.print("Encoder: ");
currentValue = myCurrentEncoderState.currentValue;
if (currentValue != prevEncoderValue) {
Serial.println(currentValue);
prevEncoderValue = currentValue;
canMsg.can_id = 0x021; // CAN id (other nano has different can id (0x036)
canMsg.can_dlc = 8; // CAN data length as 8
canMsg.data[0] = currentValue;
canMsg.data[1] = 0x00;
canMsg.data[2] = 0x00;
canMsg.data[3] = 0x00;
canMsg.data[4] = 0x00;
canMsg.data[5] = 0x00;
canMsg.data[6] = 0x00;
canMsg.data[7] = 0x00;
mcp2515.sendMessage(&canMsg);
// if currentValue stayed the same because the number is at upper/lower limit
// check if encoder was rotated by using the UpClick / DownClick-values
} else
switch (myCurrentEncoderState.currentClick) {
case NewEncoder::UpClick:
Serial.println("at upper limit.");
break;
case NewEncoder::DownClick:
Serial.println("at lower limit.");
break;
default:
break;
}
}
}
Receiver code on the Nodemcu:
#include <SPI.h> // Library for using SPI Communication
#include <mcp2515.h> // Library for using CAN Communication
struct can_frame canMsg;
MCP2515 mcp2515(0); // SPI CS Pin 10
void setup() {
SPI.begin(); // Begins SPI communication
Serial.begin(115200); // Begins Serial Communication at 9600 baud rate
mcp2515.reset();
mcp2515.setBitrate(CAN_500KBPS, MCP_8MHZ); // Sets CAN at speed 500KBPS and Clock 8MHz
mcp2515.setNormalMode(); // Sets CAN at normal mode
}
void loop(){
if (mcp2515.readMessage(&canMsg) == MCP2515::ERROR_OK) {
if (canMsg.can_id == 0x021) {
Serial.print("Raw CANmsg 0x021: "); Serial.println(canMsg.data[0]);
}
if (canMsg.can_id == 0x036) {
Serial.print("Raw CANmsg 0x036: "); Serial.println(canMsg.data[0]);
}
}
}
Now as soon as I power everything on, one of the two Nano's works fine, sending its data over the CAN network to the Nodemcu. Except, the other does nothing. Now as soon as I disconnect the power of both Nano's, and connect the one that was not working first, this one starts working correctly and the other one stops working.
I've tried switching CAN modules and Nano's, but they all give the same result.
I hope someone can help me out. Sorry for the long story but thanks in advance.
Kind regards,
Sam
