Hi,
First post.
I want to communicate between a AVR device and a PDA.
What bluetooth module would you recommend?
Neil.
I can’t say I’m the best person to answer this, but I’ll give it a shot…
Basically, it depends on what kind of communication you want to do. If it doesn’t matter, so long as you can get data from one to the other, then using Bluetooth RFCOMM is easiest, as this seems to be what most of the easy-to-use modules (like Real Networks module, etc. sold on Sparkfun) are set up for. These modules don’t need a lot of software support from the microcontroller - a lot of them are set up with rather convenient default settings, and so you can do minimal setup and then just treat it like a serial connection. They also take AT commands, like a modem, to do various bits of configuration and to allow you to manage the connection process a little better.
If you want to communicate in specific ways - for instance, to implement object exchange or something, then I think the RFCOMM modules aren’t going to serve you well, and you’d need an HCI module. If my understanding is correct, an HCI module exposes the bluetooth functionality at a low-enough level that you can implement almost whatever bluetooth protocol you want - the trade-off is that this requires more software support from the microcontroller. It’s kind of like the Bluetooth adaptors you can get for the PC, that plug into a USB port - they can do just about anything, because they rely on software on the PC side to control most of their behavior.
Terrific,
The kind of answer I was looking for.
Yes it is just basic comms between my AVR and the app on the PDA.
I will define the protocol, I just need the PDA to see it as a normal COM port.
Thanks,
Neil.