Libraries for interfacing various hardware components and ICs with ATSAM microcontrollers
Each subsystem shall define MCP9808_TWI_PORT in a platform specific header file.
The Breakout Board we use for testing.
You should set the I2C_USER_ADDRESS to a defined value. This is done by setting the A0-A1-A2 pins of the temperature sensor.
The default code in this repository is using the address 000, so the below instructions set the pins to ground.
I2C Data Pin PD27 is assigned to D20 on the Dev board
I2C Clock Pin PD28 is assigned to D21 on the Dev board
Use a pair of Pull-Up Resistors each, one from Data and one from Clock, up to VCC. For a simple connection using small jumpers, a pair of 1kΩ each is appropriate. (you can skip this step if you are using the breakout board)
| Breakout Board Pin | Connection | Notes |
|---|---|---|
| SDA | I2C Data | Connect to PD27, connector J505 of the ATSAM dev board |
| SCL | I2C Clock | Connect to PD28, connector J505 of the ATSAM dev board |
| Alert | GPIO | Unused |
| GND | Ground | Set to common ground |
| A2 | A2 | Set to common ground |
| A1 | A1 | Set to common ground |
| A0 | A0 | Set to common ground |
| Vdd | Power 3V3 | Set to 3V3 on the Power header of the ATSAM dev board |
Our breakout board currently skips two pins Pin 4 and Pin 7. For example MCP's Pin 4 is connected to the breakout's Pin 5.
The OBC subsystem uses a Magnetoresistive Random Access Memory (MRAM) which is a non-volatile memory to store critical data.
The OBC microcontroller uses the Static Memory Controller (SMC) of the External Bus Interface (EBI) to communicate with that memory. More specifically the EBI pins:
- 94 -> NRD: negative read
- 97 -> NCS0: negative chip select
- 82 -> NWE: negative write
- MEM_A[0-20]: address pins from A0 to A20
- MEM_D[0-7]: data pins from D0 to D7
The configuration for the pins is done through the SMC peripheral on the Harmony Configurator. The configuration of the SMC peripheral is as shown below for the EQM OBC/ADCS Board
