Payload Motor Board Firmware Design Specification

Warning

This is just a template, this is NOT a completed design doc, delete this line when the firmware specification is complete

Overview

Give an overview what does the firmware do, example:

Injector Sensor Hub firmware periodic reads analog sensors and report analog data to CAN, analog sensors includes pressure transducers and hall effect sensors.

Reference Documents

List of reference documents (e.g. link to hardware Datasheets), example:

Note if the firmware involves data storage or transmission(e.g. Logger SD card log, telemetry packet format), then a separate rst need to be created in the same directory, to describe data format(see Logger Data Specification for example)

Initialization

Describe step-by-step initialization sequence, example:

Use setup using external oscillator, with 4xPLL
Setup PPS(Peripheral Pin Select) for all peripherals
Initialize ADC, setup to use FVR(Fixed Voltage Reference)
Setup CAN module

Runtime

Heart Beat

Red LED shall toggle every 500ms.

Health Check

Describe what health check need to be performed, example:

Firmware shall check 12V input voltage every 500ms, and report voltage with SENSOR_ANALOG.SENSOR_12V_VOLT CAN message, if the voltage is below 11.5V or above 12.7V, the firmware shall signal error with GENERAL_BOARD_STATUS CAN message.

Sensor Reading

Describe what sensor shall be read and report to CAN bus, example:

Firmware shall read Oxidizer pressure transducer every 50 ms, ADC voltage reading shall be convert to pressure use formula described in Convert pressure transducer ADC pin voltage input to pressure section, when the pressure output be send to can use SENSOR_ANALOG.PRESSURE_OX CAN message.

CAN Communication

CAN Message Sent by Firmware

CAN Message Sent by Firmware
Message Type	Description	Period
SENSOR_ANALOG.PRESSURE_OX	Report oxidizer tank pressure	10ms

CAN Message Handled by Firmware

CAN Message Handled by Firmware
Message Type	Description
RESET_CMD	Reset board if targeted(check with `check_board_need_reset` function in canlib)

GENERAL_BOARD_STATUS board specific error field usage

GENERAL_BOARD_STATUS board_error_bitfield Bit definition
Bitfield Name	Description	Offset
PT_OUT_OF_RANGE	4-20 mA Pressure transducer signals less that 4mA or more than 20mA	0

Mathematics Model

Describe common used math equations in the firmware, if the equation is more than one line, then a link to a Matlab model should be provided.

Convert pressure transducer ADC pin voltage input to pressure

Insert formula here