Connecting the PLCDuino to Cayenne


I used your code and it compiles and uploads. That’s awesome. Only thing I have now is that the “ESP is not responding”. I’ve tried setting the power pin to high but that isn’t working.


Hi @danieljsirico,

Did you change the code in your ESP using the procedure at the top of this thread?




Yes I did and it flashed no problem. The thing is I can see the ESP in my computers WiFi if I look for networks.


Did you remove the jumper after programming, and then power cycle? Is the TTL programming header still connected to the ESP?

You shouldn’t need to jumper anything as the PLCDuino controls power to the ESP with the enableESP() function.

Did you use my code precisely? Note that the ESP is on Serial2.




I removed the jumper and power cycled. Your code is copy and pasted from your recent post with the MQTT library. I have nothing else jumpered. However, I don’t know what the TTL programming header is?


Ah right. Now I remember.

Before, if you wanted to program the ESP, you had to do it through the TTL programming header (J9) due to the baud rate detector circuitry always resetting. The jumper lets us run the helper program which routes all data received and transmitted through the Mega board directly to the ESP while enabling power to it and putting it in flash mode.

If you programmed the ESP with the AT firmware and are running my code edited with your Wifi and MQTT credentials, then I really can’t tell you why it isn’t working.

Maybe try programming the ESP again. Did you use the V1.3.0.2 firmware as linked?



I reflashed using NODEMCU and progress! now I’m getting a “Failed To Connect to WiFi”. I’m thinking password issue but that doesn’t seem right because my password is correct.


it connected! I owe you my first born child!



Just name her after me and we’ll be even.