I am trying to interface my Arduino with an Ericsson CHA-01 chatboard:
I have found various websites with information to do this, but I can get it to work. One of the sites is http://brolinembedded.se/projects/keyboard/. What I have found (some from other websites) is: - VCC should be 5V - Serial transmission is at TTL level at 9600,N,8,1 - The keyboard uses about 200mah
When I wasn't aware about the amp draw, I have tried to use the 5V directly from Arduino. That didn't work. I contacted Ericsson and they told me that I should expect the chatboard to draw 200mah. So, I set up a breadboard with a voltage regulator. Powered it with 9V from an adapter and the 5V from regulator goes to VCC on the chatboard.
I have used the SoftwareSerial to receive data on pin 2 (Arduino) at 9600kbps. I get data, also if I don't type (maybe even just if I don't type) but it is all garbage (characters like: ÅÄÖËÜåäöëü). It's even a constant stream of garbage. I seem to get some data (sometimes) when power to the chatboard is disconnected.
If someone can come up with hints where to look at, I am happy to hear from you!
Tonight I will post code.