HM-11 Bluetooth Module

Projects Programming
1

I'm using this HM-11 Bluetooth module and for some reason I can't communicate to it via Software Serial. I have an HM-10 module that works just fine with the exact same Software Serial pins (it responds to AT commands just fine), but this little HM-11 doesn't respond. I'm connecting VCC to 3.3V since I am using a 3.3V controller (32u4 Feather), GND, and TX/RX to Software Serial using the pinout from here. The back of the module also has the pinouts printed, so I can confirm that the linked pinout diagram is correct.

Here's the code I'm using:

#include <SoftwareSerial.h>

SoftwareSerial BT(10,9); // RX, TX  

void setup() {  
  Serial.begin(115200);
  BT.begin(9600);
}

void loop() {  
  char c;
  if (Serial.available()) {
    c = Serial.read();
    BT.print(c);
  }
  if (BT.available()) {
    c = BT.read();
    Serial.print(c);    
  }
}

Any ideas why it's not working? I tried another one, and same issue. I also tried 115200 baud rate, since I read here that it's the default for JDY-08.

P.S. Sorry if this isn't the right forum category for this question since the code works on HM-10. I just wasn't sure where to put it.

2

Found out that documentation on the pin functions on this thing is wrong, because it turns out that the system LED (PIO1, allegedly pin 8 on the module) is actually on the other side of the module (pin 17). The pinouts are right (like the CC2541 pins broken out are labeled correctly) but the pin functions are wrong. Now the trick is to find the correct TX and RX pins...

3

So far I've tried P02/P03 and P16/P17 for RX/TX (and I tried flipping them for each case), and to no avail. The documentation is different everywhere I look! For example, look at the sample schematics for the JDY-08 here. It show RX/TX on pins P02/P03.

4

Still cannot figure this out. I found this resource on the JDY-08 but I still can't get it to respond to AT commands. I am following the documentation and also watched a guy on YouTube try to figure this out for 2hrs and he couldn't do it either lol.

5

Did you manage?

The JDY-08 has the black rectangle piece, not to be confused with the JDY-10.

JDY-10 is the one one I managed to get uart commands working on, however I could not send any data even when connected.

JDY-08 responds +ERR to every command I send it. I read the firmware may be broke.

One thing's for sure, the Chinese are great at copying, and shite at getting things right.

I'll probably give up at spend $5/p on a Microchip or similar module.

6

Haha true dat!

By the way I actually got it working! I had to use the default 115200 baud to send AT commands to change the baud to a lower baud (like 57600) and then it would respond properly. It may be that the pinouts you've been looking at are all confused and swapped from different boards, etc. Check out my Reflowduino project using the JDY-10 (actually seems to be the JDY-08 from other pictures and user docs, who knows, who cares, I finally got it to work lol).