HC-06 Bluetooth Serial Module (HCARDU0004 & HCARDU0064)

[geoffday67]

I think the problem was around re-connecting without the previous connection being fully closed. I added code to the app around that area and now it seems robust. I wouldn't have expected the module to lock up without that code (maybe just a connection timeout worst case), but anyway it's working fine now. Thanks for your help!

If anyone's interested, the relevant code in the app is here: https://github.com/geoffday67/turntable ... ivity.java

[jack5101]

hey, im having trouble connecting my device. its pairing but it wont connect to my samsung tablet

[andrew]

its pairing but it wont connect to my samsung tablet

Could you confirm that it is pairing with this tablet? If so, although your tablet may have successfully paired with the slave module, it wont link to it until you actually open a serial terminal connection on your tablet. If you still have no luck can you also confirm the following things:

At any point does the LED go from a slow blink to being permanently on?

What software are you using to connect to the module?

You you see the module from within the app?

[jack5101]

hi, i managed to get i working through blueterm, thanks for your help

[colubridae]

Hi.

I'm thinking of getting a HCARDU0004. But only on the basis of being able to upload sketches via Bluetooth. (I'm planning to install my arduino underneath my model railway, so access will be 'not easy'.)

So can sketches be uploaded from a pc via Bluetooth (obviously my pc has Bluetooth)?

Please.

[andrew]

I doubt this would be possible. The problem is that before the program is uploaded in to the Arduino it needs to be reset to start the bootloader which then in turn accepts the program. With a programming cable this is normally this is done by using the DTR pin. However these modules do not have this pin so there's no easy way to remotely reset the Arduino.

[colubridae]

Thanks Andrew.

I will have to manage crawling around under my baseboard.

Never mind, it was a nice idea.

[ahoicaptain]

Hello,

I've seen in some projects that they use a voltage divider on the Rx pin of the module (HC-06) because its not compatible with the 5v the arduino provides(they say it needs 3.3v). Is this true? I checked the datasheet, but there wasn't anything mentioned there.

Thanks,
Dimitris

[GuitarPhil]

I am interfacing between an app I've written in Python (that I can run on both Windows and macOS), and a guitar pedal I've been working on, via a USB cable. The app sees the pedal as a serial port e.g. COM4 on Windows, and the computer and pedal communicate using simple text commands, at 57600 baud. The pedal has a USB C port connected to an ATmega2560 via a CH340 USB-Serial chip.

My question is, if I bought the pair of BlueTooth modules (a master for the PC and a slave for the pedal) could I replace the USB cable link with a Bluetooth link provided by the modules? I would need to connect the slave module to a short length of cable terminated in a USB C plug so I cold plug it in to the pedal's USB connector.

I can forsee one problem (at least!). The app relies on the ATmega2560 rebooting when the COM port is opened (this is standard Arduino behavior) and when the pedal reboots it sends an identifier string so the app knows the pedal is connected. This reset behaviour probably relies on the DTR line in the cable being pulled low, similarly to how the Arduino IDE sends a sketch to the Arduino using the bootloader. However the Bluetooth module does not provide a DTR connection.

So, I'm wondering, has anyone been able to replace an existing serial connection, via a USB cable, with these Hobby Components Bluetooth modules?

Thanks for any help or suggestions.

Phil.

[andrew]

I would need to connect the slave module to a short length of cable terminated in a USB C plug so I cold plug it in to the pedal's USB connector.

I’m not sure if I’ve misunderstood this bit but you won’t be able to connect the slave module directly to the existing USB port on the pedal. Your best option, assuming you’re willing to open and modify the pedal, is to bypass the USB/CH340 interface and connect the slave module directly to the megas serial interface. If you have access to the megas firmware you could even use one of its additional serial interfaces and keep the existing USB interface.

can forsee one problem (at least!). The app relies on the ATmega2560 rebooting when the COM port is opened (this is standard Arduino behavior) and when the pedal reboots it sends an identifier string so the app knows the pedal is connected. This reset behaviour probably relies on the DTR line in the cable being pulled low, similarly to how the Arduino IDE sends a sketch to the Arduino using the bootloader. However the Bluetooth module does not provide a DTR connection.

Yep, you’re probably correct. I’m not sure what you can do beyond fitting a physical reset button. Is there anything you can send to the pedal from your python program and just check for a response?

Apart from the above issues I don’t see why it wouldn't work. The pedal would have to not flood the modules with data and by adding these modules you’d be adding an additional latency. My guess is in the 10’s of milliseconds.

Also, if your computers have bluetooth then you may not need the master module.