APM Installation and setup

Attaching BH to a Raspberry Pi

• Install spacers to the top side of Raspberry Pi and fix them with screws from the bottom.
• Connect extension header to the 40-pin GPIO port.
• Attach BH to the extension header.
• Fix BH using screws.

RC input

• Currently BH only supports PWM signal as an input. To connect receivers that do not support PWM output you can use PWM decoder or SBUS to PWM converter. PWM receiver is powered from RCinput interfaces which was from ESC, so BEC should be present. GPIO pins connected to RC Input on BH:

29 - GPIO5
31 - GPIO6
32 - GPIO12
33 - GPIO13
35 - GPIO19
38 – GPIO20
40 – GPIO21
37 – GPIO26

Receivers with PWM output: FlySky Receiver FS-R9B.

RC output

• BES should be present. BEC would serve as back-up power supply to BH. BH support 12 channels RC outputs.
• But only one ESC central wire should be connected to BH otherwise BECs built in ESCs will heat each other.

GPS antenna

Barometer/IMU protection

• [TODO]
• MS5611 barometer (steel cap IC) is sensitive to UV light and might report sudden jumps in altitude under sunlight. It is very important to cover it with a piece of cloth (something like microphone fabric) or put autopilot in a protective case to protect it both from sunlight and airstreams.

I2C/UART/SPI Port(optional)

• Radio modems can be connected either over UART or over USB.
• For UART port use /dev/ttyAMA0 serial. Please do not connect CTS line when using 3DR Radio as RPi does not handle hardware flow control properly.

ADC pins

• On the BH you can find pads AIN0 AIN1 and AIN2, ADC range is 0-3.3V, you can connect it with the external power model which has current/voltage sensor to detect the battery state..

• Supersonic model example [TODO]

Other available GPIO pins

• GPIO pins not connected to anything on BH:

29 - GPIO5
31 - GPIO6
33 - GPIO13
36 - GPIO16

Powering BH

• BH has three power sources..

Powering USB(RPI)
Powering with RPI Power GPIO(need external power model)
Powering servo rail

• Here is an example of powering BH via PRI Power GPIOs.

IMPORTANT: ALL POWER SOURCES SHOULD PROVIDE VOLTAGE IN 4.8-5.3V RANGE, OTHERWISE YOU CAN DAMAGE YOUR BH AND RASPBERRY PI.