@gdc,
Is your nodemcu soldered to the perf board or can you remove it? If you can remove it, or you have another nodemcu, or a Serial-to-USB adapter (preferred), could you disconnect your HM-10 from your current circuit?
- Using the Arduino program, upload the blink sketch, or anything simple that doesn’t use Serial.
- Unplug the USB cable and connect the 5v, GND, and the RX, TX on the HM-10 pins to the 5v, GND, TX, RX pins on the NodeMCU. (Note to swap the RX and TX)
- Plug the board back into your computer and in the Arduino, open the Serial Monitor. On the bottom of the window, set the BAUD to 9600 and send an “AT” command. (You may need to change the line ending from ‘NewLine’ to ‘Carriage Return’ or ‘Both NL and CR’ to get a response.)
- If you don’t see a response or you see garbled text, go through all of the BAUD rates and try sending “AT” again for each. (Common ones are 9600, 38400, 57600, 115200)
- If you get a response from something other than BAUD 9600, send the command “AT+BAUD0” to set the BAUD rate to 9600.
Once you have changed the BAUD to 9600 or confirmed that it was already on 9600, unplug everything and then plug it all back into your original circuit.