/osom_firmware

Firmware to be used with speedometer hardware.

Primary LanguageC

Speedometer firmware

Note

It's not possible to debug the project with XC32 v2.10. XC32 v1.43 still works. It seems that there is a missing library.

Packets

Every packet, both received or transmitted, is made as follow:

Pos Len Meaning Value
0 2 Preamble 0x534D
2 2 Message ID
4 1 Payload length
5 1 Command ID
6 n Payload

Messages

The messages types are enumerated in firmware/src/somparser.h in the enumeration BLECommand.

Not the best name

There are 3 type groups:

  • 0x00 to 0x0F are commands reserved for the master only, managed by BLEApp;
  • 0x10 to 0x4F are generic commands to control the system;
  • 0x50 to 0x?? are response messages sent by the system to the received commands;
  • 0xF0 to 0xFF are special meaning messages sent by the system

There are also some common definitions along all the exchanged messages:

Channel selection

Value Channel
0 none
1 right
2 left
3 both
4-F reserved

TODO ACK

0x00 to 0x0F

0x00 Ping
  • Payload length 0

Simply check if the system is up and running. TODO response

TODO other commands

0x10 to 0x4F

0x10 Mode setting
  • Payload length 1

Payload data:

Field Bit Meaning
Mode 7-4 Mode selection
Channel 3-0 Channel as described above

Mode

Value Mode Channel
0 Free Start Single
1 KO System Dual
2 Given Start Single
3-F Reserved -
0x11 Start positioning

This command place the system in the so-called positioning mode.

  • Payload length: 1

Payload data

Field Bit Meaning
Reserved 7-4 -
Channel to be used 3-0 Channel as described above
0x12 Stop positioning

This command exits the so-called positioning mode.

  • Payload length: 0

0x50 to 0x??

0x51 Channel positioning status

This message notify the user about the channel status change.

  • Payload length: 1

Payload data

Field Bit Meaning
Channel 7-4 Channel as described above
Status 0 Channel status

Channel status

Value Meaning
0 The channel receiver is covered, check positioning
1 The channel receiver is receiving the laser