How to interface a Blackberry Torch with a serial device?

Question

I have a Blackberry Torch that needs to send 10 bytes per second to a serial device. The serial device will probably be a basic stamp 2 or other microcontroller. The Blackberry does not need to receive any data.

Is there an interface that will let me do this for less than $50?

Using the Wifi or Bluetooth connections are the obvious choices but those options look more expensive.

I also thought about using the headphone jack to send out different frequencies and an intermediate circuit could convert the sound into bytes, but I'm not sure where to start with that cicuit.

Thanks.

Answer 1

For under $50, you could buy an SPP bluetooth module (and a microcontroller dev board if you need one)

For $50 you can buy a complete WiFi module with a serial interface.

If you use the headphone jack, investigate Frequency Shift Keying. FSK is a modulation scheme used in audio modems.

Here's a couple of relevant projects for pointers:

• http://sree.cc/electronics/arduino/arduino-as-an-fsk-modem
• http://code.google.com/p/arduino-iphone-shield/

On the Blackberry side, you could either do the same thing, or play back pre-canned .wav files.

Answer 2

The USB port will provide wired serial (or did you mean UART/SPI/I2C?) communication cheaply. I doubt (but I don't know positively) that the Torch can act as a USB host, so you'll have to find a device capable of doing that to interface with the Torch.

Another alternative is to remove the microSD card (assuming that you don't need it), and use those connections for this purpose. There's probably an SPI port (or at least a few GPIO with which to bit-bang a serial connection) in that slot. A PCB with a right-angle connector should make this connection possible, if not pretty.