An prototype of AMR sensor project, has delivered on Jul 2010. It features as below.

     The Honeywell HMC5843, 3-Axis Magnetoresistive Sensors. 4.0 by 4.0 by 1.3mm surface mount leadless chip carrier (LCC), multi-chip module. It includes our state of the art 1043 series magneto-resistive sensors plus Honeywell developed ASIC containing amplification, strap drivers, offset cancellation, 12-bit ADC and an I2C serial bus interface. The HMC5843 utilizes Honeywell’s Anisotropic Magnetoresistive (AMR) technology that provides advantages over other magnetic sensor technologies. The sensors feature precision in-axis sensitivity and linearity, solid-state construction with very low cross-axis sensitivity designed to measure both direction and magnitude of Earth’s magnetic fields, from tens of micro-gauss to 6 gauss.

      Microchip PIC16F886, 8 bits MCU with 28-pin QFN package. It provides I2C Master and main calculation functions.

      A 100mAh Li-ion battery and bq24012 charger. It features: Small 3 mm × 3 mm MLP (QFN) Package, ±0.5% Voltage Regulation Accuracy, integrated power FET for up to 1A and current sensor.

       Its PCB is double-sided. It fits into a readily made key-chain remote controller.

       The top side PCB has HMC5843 and PIC16F886.

       The bottom side has charging IC bq24012.