A distributed and scalable autopilot architecture is attractive to me due to space and sensor positioning demands on my airframes. The existing range of autopilots simply doesn't fit. The uNode (microNode) is the result of my desperate attempts to fix this. uNode is a very cutdown version of Pixhawk with a little bit of AUAV-X2 added.
Board contents are:
- STM32F427 Processor (as per pixhawk)
- 64Mbit onboard flash - no sdcard
- 4.5V to 10V input power supply or power from USB.
- No USB connector, only 0.1" holes
- MAX21100 6dof sensor - an experiment and about the only sensor I have space for.
- No I/O buffers. ESD and EMI protection on everything.
- Power for GPS module
- SRAM Battery backup
- Pinouts for
- 2x I2C
- 3x UART
- 2x CAN with transceiver onboard
- 8x servo outputs
- PPM input
- SBUS or Spektrum module input.
Total manufacturing cost in volume may be ~$25.
These boards are designed to fit into the servo hatch of a wing. They have about the same area as a slim wing servo. There is no USB connector because there is absolutely no space for one. There is no sdcard because it is not accessible. Some other potential uses:
- As a CAN connected failproof board
- Failproof remote servo expander
- Remote sensor interface - I2C sensors over long wires without interference.
- A backup, get you home autopilot. Just add GPS module.
The board uses the same processor as the pixhawk so that the same OS and software is used. You pick whatever you need to run in what node location. The dual CAN can then be used to setup a robust network to transport the data between nodes. The PX4 firmware is structured to be very suitable for this.
The prototype hardware functions well. The onboard flash works and I have had bi-direction file transfer over mavlink-ftp working. I had it working... The PX4 codebase has taken another leap forward, broken my branch and I somehow need to catch up again.
That's all for now until I manage to make it do something useful.