Does anyone know of a compass module that’ll return heading as a voltage, rather than timed pulses or requiring an i2C interface? The qwerk board seems a bit limited in its inability to handle either of those, and the api doesn’t support the quadrature encoders either so I’m trying to find a way to work out where the thing is facing!
Compasses
Cheapy compasses maybe with not a high level of resolution, maybe usable though, are the Dinsmore sensors around $15. The ones you seem to be trying to avoid are the Devantech compass, for $57, which the Qwerk board you referenced does have I2C pins right beside the power switch, as well as quadrature encoder connections, working in this post apparently. One compass that has a serial interface (SPI) is the PNI CompassPoint V2XE, for about $75, latest version of the old Vector 2X. Or you could go all out and get a full 3 axis magnetometer combined with an IMU for $1495, having RS232, RS485, and analog voltage outputs.
Robotshop.us (or .ca) seems to have quite a number of compasses to choose from.
Cheers!
I’m aware that there have been efforts to use the qwerk i2c/quadrature hardware, but they’re a bit beyond my software expertise! I’ll chase up some of your other links (I’d only found the devantech ones before), cheers for those!