Libraries for interfacing various hardware components and ICs with ATSAM microcontrollers
Each subsystem shall define MCP9808_TWI_PORT in a platform specific header file.
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.
Data CPU Pin PD27 is assigned to D20 on the Dev board
Clock CPU 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.
| Pin Number | Connection | Notes |
|---|---|---|
| 1 | Data | Use a pull up resistor to 3.3V |
| 2 | Clock | Use a pull up resistor to 3.3V |
| 3 | Alert | Unused |
| 4 | Ground | Set to one of the dev board's grounds |
| 5 | A2 | Set to ground |
| 6 | A1 | Set to ground |
| 7 | A0 | Set to ground |
| 8 | Vdd | Set to 3V3 from the 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
