Hacktronics the other day is the HDPM01 module. The HDPM01 module includes a pressure module and a compass module. Apparently, there is also a barometer and a temperature sensor on this module.
The HDPM01 pressure module includes a piezo-resistive pressure sensor and an ADC interface. It provides 16 bit word data for pressure and temperature related voltage. With the help of a highly accurate calibration of the sensor, 11 unique coefficients were stored on the chip, thus accurate pressure and temperature reading can be realized. HM03 is a low power, low voltage device with automatic power down switching. I2C Serial Interface is used for communications with a microprocessor. Sensor packaging options are SMD (with metal cap)
The HDPM01 is a dual-axis magnetic sensor, it is a complete sensing system with on-chip signal processing and integrated I2C bus, allowing the device to be connected directly to a microprocessor eliminating the need for A/D converters or timing resources. It can measure magnetic field with a full range of ±2 gausses and a sensitivity of 512counts/gauss @3.0 V at 25°C.