Connecting to HC-06

I have an HC-06 Bluetooth module set to 57600 Bauds and paired with my PC .
And the arduino with the Standar Firmdata
But I can´t connect to Snap!

What can I do ??


Hi @kothe,

Maybe you know this... but first let's check:

  • BT connections: HC-06 TX to Arduino pin 0 and RX to Arduino pin 1
  • And that this port, COM8 from your reported capture, is the right port (where your PC has made its serial connection to that BT). I'm a Linux user and I don't have enough experience with Windows, but I remember that sometimes Windows made two ports for a BT connection, but only one is the real serial one.

If it still does not work, before checking for Snap4Arduino issues, test first your your hardware config. If your device is paired and connected and your firmware is right, connecting Arduino IDE serial console by this port (COM8) at 57600baud, your console have to receive a Firmata response. Is this right?



All the set up is right.
I found the right port and set the Bauds to 57600.
Its crazy...cause when I connect from Snap to arduino..the Bluetooth stop blinking, but do not connect to.
I only found that if I reset the board (arduino) while connecting to works..clear connection.
I have try all several times, but this one about reset while connecting works 100%. It so crazy...

One thing that I can´t do on Windows 10 is to connect to de HC-06 manualy. I only can pair it, but there is no option for connect.

Hi @kothe,

  • Yes Windows and Linux behavior is different. In Linux, after pairing we need to "connect to serial" (there is no port before doing this). So we have the BT LED fixed before connecting (to Snap!). I know in windows the serial port reference (COM port) is created just after pairing. So in Windows you begin the Snap! connecting with that LED blinking.

  • Also, in Linux, sometimes we have to "reset" manually. But not always. It is normal because normal serial connection (by USB) resets the board (then, every connection are reseting), but BT connection no. So, if the board is in a "strange" state, we must to reset it.

  • But if you have always to reset the board, and just in the connection period, maybe is different. And maybe is related to the firs point (the differences on Linux/Windows connections). I guess the problem is when Snap! wants to connect, Windows is still doing the serial connection.

Your feedback (about Windows behavior) is interesting. You can test this:

  • Try to connect normally (without reseting). I guess that connection failed, as you reported.
  • Try again to connect. Maybe it does not response, because this sprite is still "connecting". But I guess the BT LED is fixed (not blinking)
  • Create a new sprite. Then, try to connect it. Maybe this is working?


Hi Joan.
If I try to connect normaly the BT LED get fixed but got that errors.
If I try to connect again do not response.
And if I create a second sprite its the same as with the main sprite, errors.

So the trick for me is . Connect, wait for Fixed Led on BT and then reset arduino.

I think the Arduino uses pins 0 and 1 for serial communication (talking to SNAP! through USB). If I remember correctly, when the HC-06 is plugged into those pins your not going to get communication to either...

It's been a year since I figured this out... let me know what you find.

Just wanted to inject a few comments. Might be you already know these.

  • HC06 is a Slave only BT device. As such it can only accept connections. HC05, on the other hand is a master & slave device and can initiate a conn.
  • While the unit may tolerate 5V power, I/O Pins (specially Input) should be used @ 3.3V max.
  • Using the SoftwareSerial library will enable you to connect and debug at the same time by redirecting the I/O to another set of pins, while maintaining the USB link.
  • BT configuration speed is 38400, while Firmata connections are 57600.