UHF Driver

[GrahamDrive]

Write a driver library for the STM32L4 to interface with the UHF transceiver.

[GrahamDrive]

Successful Transmission of data from the custom radio driver. It is not perfect for some reason it is spamming the last character of the message, will look into it. Also adding the interrupt pin for feedback.

[GrahamDrive]

Merged the debug branch into main driver branch here #26

[GrahamDrive]

Successful Transmission of data from the custom radio driver. It is not perfect for some reason it is spamming the last character of the message, will look into it. Also adding the interrupt pin for feedback.

I think I found an error in the code below that was re transmitting the "!!!!!!!!!!!!" messages. Instead of setting it to the ready state I set it to the transmit state again. I will push a fix later.

cdh-tsat/cdh-tsat-stm32project-nucleo/Core/Src/main.c

Line 222 in 5be6ab3

S2LP_Send_Command(txCommand);

[GrahamDrive]

Code essentially complete, waiting on final testing before merging with main.

[GrahamDrive]

Testing Result

Equipment Used:

• NUCLEO-L452RE with custom COMMS board
• NUCLEO-L053R8 with S2-LP evaluation header
• Keysight Oscilloscope

Test Performed:

Jumper wires were used to connect the SPI lines of the NUCLEO-L452RE to the custom COMMS PCB.
Then, the NUCLEO-L053R8 with the S2-LP evaluation board header was attached.

Once everything was connected, the lab oscilloscope was attached to the SPI lines (MOSI, MISO, CS, SCK). Configuration settings were sent to the S2-LP board using the S2-LP DK software. After loading the registers with the correct values, the registers were read to verify the correct settings.

Results:

During testing, errors in the IC values were encountered after uploading the correct settings and attempting to read them.

The following image shows the NUCLEO-L452RE attempting to load the values (0x72, 0x2A, 0x3F, 0x86, 0x2F, 0xC2) at address 0x05:

As shown, the S2-LP responds with a system-ready state code. All other state codes seem normal except for the TX FIFO being full, which may be due to a previous attempt to load data into the FIFO without flushing it.

Next, the 0x05 register was verified. In the oscilloscope screenshot below, the NUCLEO-L452RE attempts to perform a read operation on address 0x05. The S2-LP responds with the same status codes, but as shown in red, the S2-LP does not output the expected values (0x72, 0x2A, 0x3F, 0x86, 0x2F, 0xC2) in those registers.

The reason for this issue is unknown and requires further investigation. It could be an issue with the jumper wires or the onboard circuitry.

We also attempted to send data and receive data on the NUCLEO-L053R8 with the evaluation board header and failed to communicate with the COMMS board.

Next Steps:

Testing will continue to identify the cause of this problem.

[GrahamDrive]

Seems like there may be deeper issues still with the driver in the S2-LP Driver Branch.
In the image below the radio should be sending messages once per second but only manages to transmit 5 messages then fails to send. Unclear why this is happening, every time the radio is put into TX mode the "TX data sent" IRQ is triggered if it sent a message or not.

Further investigation required.

[GrahamDrive]

AirSpy Waterfall from the STM32 flashed with most recent driver code. Seems to work as expected, previous problem seemed to be a power issue. Attached an antenna and seemed to remedy issues.

Transmission functions moving on to testing receiver.