AVRSPI provides a UNIX SOCKET & UDP service for clients to connect to in order to communicate with the controller (AvrMiniCopter-Arduino). It is mainly used to query current status, issue target position request, forward altitude reading etc.

By default AVRSPI binds to UDP port 1030 and UNIX SOCKET /dev/avrspi

Each message is of a fixed length - 4 bytes:

• control (uint8_t)
• type (uint8_t)
• value (int16_t)

Control (for incoming messages):

• currently only used when using UDP
• 0: do not remember the client, just process the incoming message
• 1: remember the client and process the incoming message
• 2: remember the client and ping back

Control (for outgoing messages):

• 0: a regular message
• 1: disconnect request

Type:

• messages with type 0 will be handled by AVRSPI Values:
  • 0: dummy message
  • 1: reset backend and initiate autoconfig
  • 2: reset backend but do not initiate autoconfig
  • 3: get number of CRC errors for incoming SPI transfers
  • 4: save flight log
• all other types will be forwarded to the backend; see the backend documentation

When connecting over UNIX SOCKET the client needs to send the required connection type as the first byte. This is:

• 0: normal bi-directional connection
• 1: one-way connection - in this case AVRSPI will not be sending any information back to the client (useful for services like barometer reader and similar)

• remove flight log and configurator