Connect 2 Bluetooth phone/serial connection to the same Arduino.

Hello everyone,

I have made a project for my car's air suspension. It's basically 4 relays controlled using an android app . It is working perfectly as of now using the HC-05 to connect with Bluetooth.

I'm taking the project to the next step and I'd like to keep the Arduino always connected to my android display (Added the display recently). And also be able to connect to the Arduino from my android phone whenever needed. HC-05 cannot connect to multiple devices at once.

Can I connect 2 HC-05 to the same Arduino and keep one always connected to the display and the new HC-05 for me to connect with the phone?

My doubts are :

  1. Will I have to use Software serial?
    Can I do without software serial because with Software serial I won't be able to monitor both serials simultaneously..

  2. Is it possible to connect both the HC-05s to the same serial port ?
    (I can't try it yet because my HC-05 I ordered is taking longer than usual because if Corona.)

Sorry for making it too long to read..
Thank you!

Use a Mega or other processor with multiple hardware serial ports. Then you can use more than one HC05 and have Serial left to upload code, monitor program output and debug.

You cannot connect more than one device to a serial port and expect reliable communication.

groundFungus:
Use a Mega or other processor with multiple hardware serial ports. Then you can use more than one HC05 and have Serial left to upload code, monitor program output and debug.

You cannot connect more than one device to a serial port and expect reliable communication.

As of now I'm using a Nano. Really trying to make the project as small as possible. But I think if I have no other option I'll go with Mega.

Thank you.

Look into Teensy microcontrollers. They have a small footprint, large amounts of processing power, and multiple hardware serial ports.

Power_Broker:
Look into Teensy microcontrollers. They have a small footprint, large amounts of processing power, and multiple hardware serial ports.

Didn't really think of anything else other than Arduino as of now.
I'll take a look at Teensy too. I'm not really super good with programming. I hope Teensy uses similar language like Arduino..

I'm thinking of using Mega 2560 Pro? It's not that big I feel.

3rroR431:
Didn't really think of anything else other than Arduino as of now.
I'll take a look at Teensy too. I'm not really super good with programming. I hope Teensy uses similar language like Arduino..

It uses the Arduino IDE for programming, so it's basically identical to normal Arduinos in terms of software.

Power_Broker:
It uses the Arduino IDE for programming, so it's basically identical to normal Arduinos in terms of software.

Just took a look! I think it'll satisfy my needs. Thanks for the idea.
Only that Teensy 3.0 isn't really cheap for me to burn it.

As of now I'm using a Nano. Really trying to make the project as small as possible. But I think if I have no other option I'll go with Mega.

The new Nano Every based on the 4809 has a USB Serial port, a separate hardware Serial port, and can run one instance of software serial.

3rroR431:

  1. Will I have to use Software serial?
    Can I do without software serial because with Software serial I won't be able to monitor both serials simultaneously..

Clearly, you will have to use software serial if you stay with the Nano, but only once. Software serial is never such a great idea, but it may be quite OK and it would be stupid to rush out and buy a Pro Mega without trying it. All you need do is disconnect HC-05 from pins 0,1 while uploading your programme. No sign of the code, or baud rates, but you should be able you should be able to monitor software serial and hardware serial at the same rate as two hardware serials.

Nick_Pyner:
Clearly, you will have to use software serial if you stay with the Nano, but only once. Software serial is never such a great idea, but it may be quite OK and it would be stupid to rush out and buy a Pro Mega without trying it. All you need do is disconnect HC-05 from pins 0,1 while uploading your programme. No sign of the code, or baud rates, but you should be able you should be able to monitor software serial and hardware serial at the same rate as two hardware serials.

I'm using Hardware serial right now (TX, RX pins). So disconnecting it for programming isn't really a problem as of now.

I think I'll give it a try with Software Serial. If I end up not being able to do it, I'll try with a Teensy.

Thanks everyone for the Help!

cattledog:
The new Nano Every based on the 4809 has a USB Serial port, a separate hardware Serial port, and can run one instance of software serial.

Teensy looks a bit more easier, I guess.

Thanks for the suggestion.