Controlling BC127 discovery board with arduino

I am using a BC127 Discovery board and I’m trying to control the BC127 on the discovery board via the UART pins on an arduino. I have tried to tap directly onto the UART Header and sending the desired message, however when viewing the signal, I can see that the pin remains high always. I suspect this has something to do with the FT232R being hard wired directly to the BC127 UART pins, preventing the signal from going low (as seen in the image below). I have tried powering it off the “USB to Host” (CON1) as well as off J7, but I still only get a high signal. Is there a way that I can command the BC127 discovery boar via the UART header?

I have found the solution to my problem. SW1, which is not labelled on the development board schematic, allows me to connect and disconnect the BC127 from the FT232R. I can now command the BC127 via a arduino.

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Hi, apologies for hijacking the topic- but how have you wired this up and how did you set the switch?
I’m just getting going with mine today, I’ve tried the TX/RX on Arduino both ways round to pins 1 and 4 on the UART header (I think- they aren’t labelled, but with the text “UART Header” the right way up, these would be 2 and 5, I think 1 is the earth) - but the software on Arduino is returning -2 for everything, which I think is timeout…
Any hints to get me going? Thanks!

Hey jmbillings,

It is not clear when looking at the discovery board which is pin 1 and 5, so the best method is to use a multi-meter and find which is ground and go from there. I put this away a while ago now, so I don’t have a record of what I did.
However, I know that you should just need to connect:
Arduino -----------BC127
Also remember that the arduino is operating on a 0-5V digital interface while the BC127 is 0-3.3V, so you’ll need to resolve this by hardware or reprogramming the Arudino to operate on 3.3V.
As for setting switch 1, just move all 4 of the switches on SW1 to the off position.
Sorry I don’t have a schematic or anything, it’s just been a while since I looked at this. Hope this helps.

Thanks for that, definitely a couple more things to check, I’ll dig out the multimeter later!


I a hardware set up like yours and am also returning -2 from the BC127. I’ve got SW1 set to off. Which version of Melody are you using?

I used firmware Melody 7.2

Hi @beau_rogers did you use any arduino library for the commands, If not how were you writing the command to the serial port. I’m a beginner to this please assist.

I didn’t use any special library. I just wrote strings to the serial port, the same way you might want to write a message to your computer screen. But ensure your baud rate is set correctly. So something along the lines of
Serial.print(“RESET\r”); //Note the ‘\r’

I haven’t looked at this in over 6 months so that is all the details that I can think to give.