LISSA FM Gyroscope Interface Test

Introduction

Test Description: Testing the interface between CDH and ADCS with focus on operating and configuring the gyroscope "in flight". *NOTE* This test can be performed in parallel with the FM Magnetometer Test.

Completed: 

Documented by: Riley Sweeney

Resources Required:

• Tools: Required tools such as cleaning equipment, chemicals, jigs, hand tools, etc.

• Hardware and Equipment: LISSA FM FlatSat, power supply, Microsemi fusion, Atmel ICE, USB to TTL device, laptop to interface with both boards.

• PPE: FM testing will occur in the clean room. Please follow all clean room safety guidelines. Please wear an ESD bracelet and use ESD mat when working with electronics.

Verification Activities: R-LIB-ADC-005-6964. R-LIB-ADC-032-6371. R-LIB-ADC-240-7001.

Pass Criteria: The gyroscope shall be able to change its configuration upon command from CDH (R-LIB-ADC-005-6964) (ADC-032-6371). The gyroscope shall output rotation data to CDH at a minimum of 5 Hz (R-LIB-ADC-240-7001).

Test Apparatus

This test will occur on the FM FlatSat.

1. Check the connections between PCBs on the FlatSat. The power PCB should be connected to a power supply with two wires for power and ground. This PCB should also connect to CDH using an intermodular connector.

2. The CDH PCB should have two intermodular connectors, one coming from the Power PCB, and one going to the AODCS PCB.

3. The gyroscope is located on the AODCS PCB. No other peripheral sensors or actuators need to be connected to AODCS.

Test Set-Up

With the FlatSat set up, this section focuses on setting up the necessary software for the PCBs and data collection.

CDH:

1. Connect the Microsemi fusion to the debug port on the CDH CCA. Connect the other end of the Microsemi fusion to your laptop via USB.

2. Using SoftConsole, comment/uncomment test scripts in the CDH code as needed. Be sure to build before uploading.

3. Disconnect the Microsemi fusion.

AODCS:

1. Connect the Atmel ICE to the debug port on the AODCS PCB. Connect the other end to your laptop via USB.

2. Using VS code, uncomment the AODCS test scripts in the main.h file as needed. For this test it will be TEST_GYROSCOPES.

3. Build the project and upload by running in debug mode.

4. Disconnect the Atmel ICE when upload is complete.

Debugging/Recording signals:

• Connect the USB to TTL device to the UART pins on the J1 header on CDH. Connect the device to your laptop to receive data from CDH.

• Connect the USB to TTL device to the UART pins on the J1 header on AODCS. Connect the device to your laptop to receive data from AODCS.

Test Procedures

The first part of the test will check for function on the AODCS board itself.

1. Set the output voltage on the power supply to 6.4 V, which is approximately bus voltage.

2. Turn on the power supply. The power PCB will boot into critical hold mode, you must wait for this period to end for power to be supplied to CDH and AODCS. The output current on the power supply will jump when this period ends.

3. Uncomment TEST_GYROSCOPES in main.h, and comment out any other defines if needed. This will run a3g4250d_read_data_polling.c, which initializes, configures, and collects data from the gyroscope.

4. In a3g4250d_read_data_polling.c, add a breakpoint on line 263, after the line where a3g4250d_angular_rate_raw_get is called.

5. Build the project and run in debug mode to flash the AODC board MCU. The code should run up to the breakpoint.

6. Right click on the variable data_raw_angular_rate and scroll down the option menu to click on "add to watch". The variable should show up in the toolbar on the left.

7. Click continue to loop to the breakpoint again, the values of the variable should change slightly due to noise.

The second part of the test involves configuring and collecting data from the gyroscope using commands from CDH.

1. On the AODCS code, comment out TEST_GYROSCOPES and uncomment ADCS_MAIN. This will enable the AODCS to process commands from CDH. 

2. Build and run the code as before to flash the board MCU.

3. On CDH, edit the testSPI script to send all gyroscope configuration commands to AODCS. These are as follows:

   1. ADCS_GYRO_GET_ODR, // 0x16

   2. receive response (1 B) // 0x00

   3. ADCS_GYRO_SET_ODR, // 0x17

   4. A3G4250D_ODR_100Hz   // 0x0F

   5. ADCS_GYRO_GET_LP_BANDWIDTH, // 0x18

   6. receive response (1 B) // 0x00

   7. ADCS_GYRO_SET_LP_BANDWIDTH, // 0x19

   8. A3G4250D_CUT_OFF_MEDIUM     // 0x01

   9. ADCS_GYRO_GET_HP_BANDWIDTH, // 0x1a

   10. receive response (1 B) // 0x00

   11. ADCS_GYRO_SET_HP_BANDWIDTH, // 0x1b

   12. A3G4250D_HP_LEVEL_0   // 0x00

   13. ADCS_GYRO_GET_HP_MODE, // 0x1c

   14. receive response (1 B) // 0x00

   15. ADCS_GYRO_SET_HP_MODE, // 0x1d

   16. A3G4250D_HP_NORMAL_MODE_WITH_RST // 0x00

   17. ADCS_GYRO_GET_HP_REFERENCE_VALUE, // 0x1e

   18. receive response (1 B) // 0x00

   19. ADCS_GYRO_SET_HP_REFERENCE_VALUE, // 0x1f

   20. uint8_t hp_reference // 0x00

   21. ADCS_GYRO_GET_FILTER_PATH, // 0x20

   22. receive response (1 B) // 0x00

   23. ADCS_GYRO_SET_FILTER_PATH, // 0x21

   24. A3G4250D_LPF1_HP_LPF2_ON_OUT  // 0x06

   25. ADCS_GYRO_GET_MEASUREMENT, // 0x15

   26. receive response (6 B) // 0x00 (x 6)

4. Connect logic analyzer to the SPI ports on the J2 header of CDH.

5. When ready, build the CDH code and flash it to the board. Simultaneously begin capturing on the logic analyzer.

6. You should see commands and responses for both CDH and AODCS while the test runs.

7. Once the code has run, stop capturing the logic analyzer, and save the capture for documentation.

Test Close-Out

1. Disconnect the USB to TTL device upon test completion.

2. Turn off the power supply.

3. The FlatSat does not need to be disassembled.

Data Analysis

Open the saved capture in Logic. Zoom in on the MOSI channel, and confirm the command sequence follows that which was provided in the procedure steps, and responses from AODCS (on the MISO line) make sense.