sharing a serial problem and solution ArduinoBT

Hi all,

I spent a great deal of time this week on getting a LCD03 from Devantech up and running.

My original set-up: ArduinoBT -(serial TX_line PIN1)-> ArduinoMini -(softserial)-> LCD03.

And of course all the ground lines connected.

I discovered that when communicating to the display at a boutrate of 9600 and getting data over the serial line from the Blutooth Arduino (at 115200 boutrate), that even when I did not read from the serial bus there was still disturbance on the display.

It might be a case of shielding, but it seemed more fundamental. So after a lot of tweaking and peaking I decided to change to I2C.

My current set-up: ArduinoBT -(serial TX_line PIN1)-> ArduinoMini -(I2C)-> LCD03.

Important notice is that I2C communicates with the Arduino with 7bits of information while the address of the LCD is 8 bits. You have to skip the least significant bit so my LCD can be called using 63 as address in stead of C6.

I hope this information might be valuable for anyone.