view wiki/Modules.md @ 571:91a8f9893e68

Reactivate compass parameter stored in NVM: The calibration parameters are stored in NVM but the automatic restore function during startup was no longer active. As result the compass needed to be calibration after every RTE update. In addition compass HW was detected at every startup causing some i2c "trouble" because of adressing not available devices. The compass HW info is now stored together with the calibration parameters to avoid i2C problems.
author Ideenmodellierer
date Wed, 25 Nov 2020 20:16:20 +0100
parents 0e7c16dd774d
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# OSTC4 Code Modules #

## Main CPU - aka CPU1-Discovery ##

For historical reasons, the firmware of the main CPU was divided in three parts.
It helps development, allow smalled upgrades, and improve security as a bad manipulation won't kill the bootloader, responsible fot the next firmware upgrade.

### Bootloader ##

The code responsible to upload new firmwares for both CPU.

### Font Pack ###

This module does not contains any code. Just font data and images.

### Firmware code ###

The main OSTC4 firmware. The more important modules are:

- Buehlmann decompression algorithm.
- VPM decompression algorithm.
- The simulator and dive planner.
- Logbook display (surface and dive mode).
- All user interface code, during dive or surface mode (`t*.c` files).
- Graphics (gfx) engine.
- Plus interface to the other CPU, the management of the _LCD_ screen, and the optional _Bonex_ scooter interface (No longer supported)

## Small CPU - aka CPU2-RTE ##

The _Real Time_ CPU handle everything that requires precise timming to function perperly.

The most important modules are:

- Real time computation of gas exchanges during dive (aka the _LifeData_ structure).
- Analog to digital conversion for the ... ambient light sensor.
- I2C bus interface to the pressure sensor, the magnetic compass and the battery gauge.
- SPI bus interface to the buttons and to the other CPU.
- Serial interface to the _RS232-over-Wireless_ connection.