Code Signal Flag from inverter to indicate CAN comms is working?

[rooftopsolarsa]

Hey ArminJo :)

I am trying to add status LED's to show if COMMS is working or not.

On the JKBMMS side I have managed to adjust/add to the code to allow LED to be on/off depending on status of BMS comms working or not.

I have defined STATUS LED's for CAN and BMS and POWER status
Then..
AT LINE 698 in JK-BMSToPylontechCAN.ino

bool readJK_BMSStatusFrame() {
    sMillisOfLastReceivedByte = millis();
    uint8_t tReceiveResultCode = readJK_BMSStatusFrameByte();
    if (tReceiveResultCode == JK_BMS_RECEIVE_FINISHED) {
        /*
         * All JK-BMS status frame data received
         */

// START MY CODE HERE TO SWITCH ON LED
digitalWrite(BMS_STATUS_LED_PIN, HIGH); // Turn on LED IF BMS CONNECTED and Receiving - WORKING
// END MY CODE

        return true;

    } else if (tReceiveResultCode != JK_BMS_RECEIVE_OK) {
        /*
         * Error here
         */

// START MY CODE HERE TO SWITCH OFF LED
digitalWrite(BMS_STATUS_LED_PIN, LOW); // Turn on LED IF BMS CONNECTED and Receiving - WORKING
// END MY CODE HERE TO SWITCH OFF LED

        Serial.print(F("Receive error="));
        Serial.print(tReceiveResultCode);
        Serial.print(F(" at index"));
        Serial.println(sReplyFrameBufferIndex);
        sFrameIsRequested = false; // do not try to receive more
        sBMSFrameProcessingComplete = true;
        printJKReplyFrameBuffer();
    }
    return false;
}

Now I want to do the same for the CAN side.
In the code I can find where to see status if CAN Module is on or not. But I cannot find any code which shows any signal/flag/callback coming from the inverter to say all comms are working.

Currently it looks like the CAN is one-way only, sending to the inverter, and nothing coming back from the inverter?
Or advise suggest another way to know in the code if CAN is communicating or not?

[ArminJo]

Yes you are right. The CAN communication is one way. I do not try to receive any response or acknowledge from the inverter, but maybe there is a response or acknowledge I am not aware of.

[rooftopsolarsa]

Ok great, I thought I was going crazy to not find anything coming back from inverter.
So it will have to be enough to know the CAN MODULE is working by showing LED on.
Now I can maybe just flash the led each time CAN is sent to inverter.

In your code at line 546 in JK-BMSToPylontechCAN.ino

    /*
     * Send CAN frame independently of the period of JK-BMS data requests
     * 0.5 MB/s
     * Inverter reply every second: 0x305: 00-00-00-00-00-00-00-00
     * Do not send, if BMS is starting up, the 0% SOC during this time will trigger a deye error beep.
     */
    if (sCANDataIsInitialized && !JKComputedData.BMSIsStarting
            && millis() - sMillisOfLastCANFrameSent >= MILLISECONDS_BETWEEN_CAN_FRAME_SEND) {
        sMillisOfLastCANFrameSent = millis();

          digitalWrite(CAN_STATUS_LED_PIN, LOW); // Turn OFF LED IF CAN SENT
          delay(20);
          digitalWrite(CAN_STATUS_LED_PIN, HIGH); // Turn ON LED BACK ON

        if (sDebugModeActivated) {
            Serial.println(F("Send CAN"));
        }
        sendPylontechAllCANFrames(sDebugModeActivated);
    }

I am just not sure how the delay(n) will affect the timing in your code?
Or do you have a better more elegant solution to flash the LED each time CAN is sent to the inverter?

[ArminJo]

Thanks for the inspiration 🥇
I added code for communication status LEDs and tested it.

[rooftopsolarsa]

Nice...
Am going to try it out this evening and see how it works :)