This is the new APM 2.8 autopilot module, upgraded Version 2.5 2.6.
Out of the V2.52 version of the old 1.0mm 6P SM06B GPS interface, I2C interface to external compass DF13-4P, DF13-5P GPS interface and external compass interface is placed together, with more convenient GPS and external compass. The original DF13-5P GPS interface and SM06B GPS interface function reuse, no significance.
This revision of the board has onboard compass. V2.8 improved the design, use jumper selection, MAG markers found on the board pin plug(Near to GPS connector), jumper cap for a built-in compass, unplug the jumper cap for external compass.
One of the first open source autopilot systems to use Invensense's 6 DoF Accelerometer/Gyro MPU-6000.
V2.52 version of the 3.3V power supply using TPS79133, rated output capacity of only 100mA, also need to six (including onboard compass, gyroscope, pressure gauge and 3 logic level conversion) IC power supply, power supply capacity is insufficient, and because the TPS79133 is a low voltage enable, cannot use other LDO chip substitution. The new version of V2.8.0 use Micrel MIC5219-3.3, output capacity reached 500mA. To strengthen the ability of the 3.3V output, you can reduce some problems due to the voltage Bad Gyro health probability.
The I2C V2.52 interface to the multi functions of MUX interface, the interface by the user's own output, free allocation function pads through the back of the board of the UART0, UART2, I2C, OSD optional, the default is OSD interface, to avoid the 2.52 version to use both digital and OSD, need to use the Y line interface separation scheme. OSD interface with the improved data transmission at the same time, when in use, due to the isolation resistance, effectively avoid the interference from the log.