BT Arduino Uno readable. BT Arduino Pro MINI output is garbage.

Cross post from another thread, that forum didn't seem to have much traffic. (

I have a Android Pro Mini v3.3 w ATMega 328 8mhz and an Arduino Uno 16mhz. I have a RN-42 BT module setup on a breadboard. I've been uploading sketches to the Pro Mini through the Uno. (no direct FTDI programmer chip)

SoftwareSerial BT @ 19200 (and tried 9600 too) Serial.begin @ 9600

When using the Uno + BT and monitoring it, everything works as expected. Button presses, everything is readable in cleartext.

When using the Pro Mini + BT and monitoring it, the output is garbage; fractions and various ASCII characters. However, it seems that program is on there because it does respond to the buttons properly and the garbage output is consistent.

So when I press the button on Uno, I'll get "Press".. but Pro Mini says "½"

I'm not sure where to start debugging this. It seems that the program is properly uploaded because it responds to button clicks as you'd expect but the output is crap... like it's on the wrong baud, but it's not. I've tried multiple bauds and it always fails.

Anyone have a good place to start?

It is probably a serial speed problem.

I'm using SerialTools connecting to /dev/

I've changed the Baud to everything.

It always reports this: ï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ìï­Ì

That's a sequence of multiple baud checks. 2400, 9600, 19200, and 115200. I've tried that on multiple settings internally too. The output above is all the same across all baud connections.

Here's a video screen cap switching between baud connections and showing that the output is always the same garbage.

mySoftwareSerial is set @ 9600 and prints a line every second in the loop.