Digital compass
All information pertains to the N900.
Contents |
Connection options
- Optical (use one of the cameras, plus image processing)
- Best to use user-facing camera, so the world-facing can be used for capturing the world image for AR
- USB
- Unknown if USB host possible.
- Unknown if power is available from USB.
- IRDA
- Seems unsupported at this point
- Bluetooth
- Bluetooth data
- Bluetooth audio - sending analog signals via Bluetooth microphone for digital signal processing on the N900
- FM radio
- Requires headphones be connected
- Signal processing of audio in software
Compass chips or sensors
- Honeywell HMC5843
- I2C interface
- Magnetometer requires vector math on client side for interpretation, see OpenMoko i2c compass project for more info
- Dinsmore analog
Ready-built compass modules
- Ocean Server OS4000
- Ocean Server OS5000
- USB and RS232 interface
Microcontrollers
Converters
- I2C to RS232
- RS232 to Bluetooth
- Sparkfun BlueSmiRF Gold
- I2C to USB
- I2C to Bluetooth
- http://www.emv-electronics.com/de/intro/i2cbusadapter.htm (seems unavailable for purchase)
Designs
Optical image processing of compass
- Periscope-like mirror