Userspace Arduino:cape ideas 2

Ideas for hardware for the Beaglebone Black, which can be used to interface with peripherals like SPI, I2C etc.

I2C
It would be advantageous to go with devices which have existing Arduino sketches, since they are more likely to be widely used and tested with. A quick check at a local vendor revealed the following common sensors/devices being used with the I2C bus


 * BMP085: Barometric Pressure Sensor Module,
 * MPU-9150: Accelerometer + Gyro + Magnetometer
 * DS3231, DS1331 are very popular RTC chips and can be easily integrated using the Time library

SPI

 * SCP1000: Barometric Pressure Sensor Module
 * SHARP Memory Display: A very cool display which is a cross between an e-ink display and an LCD.
 * PN532 NFC/RFID: A popular (I have this one!) RFID chip with breakout board which is compatible with several protocols. Could be really cool, except for the part where an antenna might need to be embedded in the cape.

PWM

 * SD Card Audio: A great way to get audio output from the Beaglebone using one (or two) PWM outputs.