Hi,

I'm trying to figure out the simplest way of communicating between two mbeds, requiring the least amount of external electronics? It's not required to have two way communication, but it would be nice.

Basically I want the master-mbed to send commands to the slave mbed, in this case it is a multicopter-platform sending different commands to a gyro stabilized 3-axis camera gimbal.

Anybody got any ideas? Should I use i2c, canbus, ethernet, serial, USB? What would be simplest? And possibly, what would be the method requiring the least amount of resources?

Thanks!

Simplest is probably Serial. Since both sides can just send something whenever they like it, and there is no slave that can only send something when the master allows it. You can just connect TX/RX and RX/TX. I can imagine a multicopter has alot of electric interference from the motors. In that case putting RS232/485 chips in between will decrease that, but from your description it is not that critical (it would be if one had the IMU calculations and the other one controlled the motors), so I would just try it first with direct connections.

I2C doesn't offer much that Serial doesn't. For sensors the advantage is a clock signal is send with the data, but both mbeds will have an accurate clock.

SPI has same as I2C.

Canbus should be interference robust, after a level conversion IC, so same as Serial but way more complicated.

Ethernet is included on the LPC1768s of course, and already has a differential output, but the complexity is alot higher than serial, so also the overhead.

Same for USB.

Thank you very much for the introduction to the different methods of communicating. I'll try with serial to begin with. The distances between the two mbeds are really short, so I'm thinking that it should be possible to connect them directly.