I have wired my HM-10 Bluetooth module (pictures at bottom) from DSD tech into my Arduino Uno with the following wiring:
VCC = 3.3v on Arduino
GND = ground on Arduino
TXD = RX on Arduino
RXD = TX on Arduino with voltage divider
I am running an extremely simple sketch on the Arduino as you can see from the picture below
When I type "AT" (without the quotes of course) into the serial monitor, no response appears whatsoever. I've tried:
the SoftwareSerial library
switching the tx and rx pins
connecting to it via raspberry pi Bluetooth where it fails to connect
Sending power to the enable pin on the Bluetooth module before I turn it on, which should put it in command mode but given that the light has only blinked slowly since I got it means that it's been in command mode which is why I am so confused.
This is also my third Bluetooth module I've tried, so I think I've ruled out the device being faulty (different brand each time)
I have also tried using an Arduino mega to which I got the same results
I've been working on this for days and I am admitting defeat on my own and am looking to you very helpful people. Thanks!
technics093:
I have wired my HM-10 Bluetooth module
VCC = 3.3v on Arduino
Check the power requirements on back of the breakout board? The code you have posted is either incomplete or meaningless.
Reversing the Rx/Tx connections is as futile as the labels imply.
Sending power to the EN pin will get you nowhere, as it isn't connected to anything. HM-10 is is in AT mode by default. I guess the first thing you need to consider is if you really need to use AT mode anyway. It is quite likely that you don't.
Using a raspberry Pi probably just moves the problem rather than fixing it. Unless you mean you want to talk to another Bluetooth, you will be much better off using a BLE terminal on a phone.
You are probably correct, all three modules were fine, it is just that you don't know what you are doing. The modules are probably still fine, btw.
Using a Mega won't fix anything, so put it aside for the moment.
You might find the following background notes useful.
You will find more HM-10-specific stuff on the Martyn Currey website.
