Recently I bought the HM-10 BLE Bluetooth module and connected it to an arduino uno like this:
STATE ->
RXD -> TX
TXD -> RX
GND -> GND
VCC -> 5V
EN ->
Then I tried to connect with 2 different android smartphones (both supporting BLE). Both smartphones failed to pair with the hm-10 module. Only one of the smartphones could connect using a specific android app. The other smartphone failed to connect using the same app.
briler:
Both smartphones failed to pair with the hm-10 module. Only one of the smartphones could connect using a specific android app.
Others have had grief with the HM-10, but this is nonsense. What exactly happened, and what was the Android app?
Your connections are essentially correct, but it is a good idea to use a 1k/2k voltage divider in Arduino's Tx line
First of all the app is called Bluetooth4.0 for arduino (on play store). I tried to connect via this app using 2 different devices (lenovo, mls) both had bluetooth turned on. When I tried to press scan (in the app) the mls smartphone could connect to hm 10 module and send data but the lenovo didnt even show me the address of the module.
OK, so the real story is that the mls phone is fine but the Lenovo is not, and couldn't even see the module, right?
This rather suggests it is not an HM-10 problem, but more a Lenovo problem. I had the exact same problem with a tablet and an HC-06. I found that the tablet worked fine with a bluetooth keyboard, so I tried an HC-05 and it was fine. The tablet died shortly after. I then put the HC-06 back into service and it works fine with the replacement tablet and a phone. I'm pointing the bone at the original tablet, but I'm afraid I was never sure.