Refactor communication and protocol

[bessman]

Rework communication to happen in a single place: src/transport/packet_handler.c

New protocol has two main differences from the old one:

1. Every exchange starts with a header which says how many bytes will be sent.
2. Acknowledgement is mandatory.

Remaining modules to update to new protocol:

• I2C
• SPI
• UART
• buffer
• debug
• device
• interval
• light
• rtc
• logicanalyzer
• multimeter
• oscilloscope
• powersource
• sensors
• wavegenerator
• ctmu
• pin_manager
• system
• sdcard
• commands

[sourcery-ai]

Reviewer's Guide by Sourcery

This pull request refactors the communication protocol and command structure of the PSLab firmware. It introduces a new packet handler for managing communication between the PSLab and the host, and updates all instruments and helper functions to use the new protocol. The new protocol includes a header with command code and payload size, mandatory acknowledgements, and a single entry point for communication. The changes also include input validation, status return values, and removal of debug messages.

Sequence diagram for sending a command to the PSLab device

sequenceDiagram
    participant Host
    participant PacketHandler
    participant Instrument

    Host->>PacketHandler: Send command with header (command code, payload size) and payload
    activate PacketHandler
    PacketHandler->>PacketHandler: Validate header and payload size
    alt Validation fails
        PacketHandler-->>Host: Send error acknowledgement
    else Validation succeeds
        PacketHandler->>Instrument: Call instrument function with payload
        activate Instrument
        Instrument-->>PacketHandler: Return status and response data
        deactivate Instrument
        PacketHandler->>PacketHandler: Prepare response packet
        PacketHandler-->>Host: Send acknowledgement with response data
    end
    deactivate PacketHandler

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File-Level Changes

Change	Details	Files
Refactored the wave generator instrument to use a new command structure and data handling.	Replaced individual UART read calls with a single args array for command parameters. Added status return values to all functions. Removed UART write calls and instead return data via the rets array. Added input validation to check the size of the args array. Replaced response_t with enum Status. Added a downsample function to generate short waveform tables from full waveform tables. Changed the sine table definitions to use WAVE_TABLE_FULL_LENGTH and WAVE_TABLE_SHORT_LENGTH.	src/instruments/wavegenerator.c src/instruments/wavegenerator.h
Refactored the I2C bus communication to use a new command structure and data handling.	Replaced individual UART read calls with a single args array for command parameters. Added status return values to all functions. Removed UART write calls and instead return data via the rets array. Added input validation to check the size of the args array. Replaced response_t with enum Status. Removed the I2C_BulkWrite and I2C_BulkRead functions. Added helper functions for I2C communication, such as I2C_StartSignal, I2C_StopSignal, I2C_Transmit, and I2C_Receive.	src/bus/i2c/i2c.c src/bus/i2c/i2c.h
Refactored the UART bus communication to use a new command structure and data handling.	Removed interrupt handlers for UART1 and UART2. Replaced individual UART read calls with a single args array for command parameters. Added status return values to all functions. Removed UART write calls and instead return data via the rets array. Added input validation to check the size of the args array. Replaced response_t with enum Status. Added functions for setting parity, stop bits, and baud rate. Added functions for reading and writing data to the UART bus. Removed passthrough mode functionality.	src/bus/uart/uart.c src/bus/uart/uart.h
Refactored the SD card communication to use a new command structure and data handling.	Replaced individual UART read calls with a single args array for command parameters. Added status return values to all functions. Removed UART write calls and instead return data via the rets array. Added input validation to check the size of the args array. Replaced response_t with enum Status. Added functions for mounting, unmounting, opening, closing, reading, and writing files.	src/sdcard/sdcard.c src/sdcard/sdcard.h
Refactored the oscilloscope instrument to use a new command structure and data handling.	Replaced individual UART read calls with a single args array for command parameters. Added status return values to all functions. Removed UART write calls and instead return data via the rets array. Added input validation to check the size of the args array. Replaced response_t with enum Status.	src/instruments/oscilloscope.c src/instruments/oscilloscope.h
Refactored the logic analyzer instrument to use a new command structure and data handling.	Replaced individual UART read calls with a single args array for command parameters. Added status return values to all functions. Removed UART write calls and instead return data via the rets array. Added input validation to check the size of the args array. Replaced response_t with enum Status.	src/instruments/logicanalyzer.c src/instruments/logicanalyzer.h
Refactored the multimeter instrument to use a new command structure and data handling.	Replaced individual UART read calls with a single args array for command parameters. Added status return values to all functions. Removed UART write calls and instead return data via the rets array. Added input validation to check the size of the args array. Replaced response_t with enum Status.	src/instruments/multimeter.c src/instruments/multimeter.h
Refactored the power source instrument to use a new command structure and data handling.	Replaced individual UART read calls with a single args array for command parameters. Added status return values to all functions. Removed UART write calls and instead return data via the rets array. Added input validation to check the size of the args array. Replaced response_t with enum Status.	src/instruments/powersource.c
Refactored the buffer helper functions to use a new command structure and data handling.	Replaced individual UART read calls with a single args array for command parameters. Added status return values to all functions. Removed UART write calls and instead return data via the rets array. Added input validation to check the size of the args array. Replaced response_t with enum Status.	src/helpers/buffer.c src/helpers/buffer.h
Refactored the RTC helper functions to use a new command structure and data handling.	Replaced individual UART read calls with a single args array for command parameters. Added status return values to all functions. Removed UART write calls and instead return data via the rets array. Added input validation to check the size of the args array. Replaced response_t with enum Status.	src/helpers/rtc.c src/helpers/rtc.h
Refactored the device helper functions to use a new command structure and data handling.	Replaced individual UART read calls with a single args array for command parameters. Added status return values to all functions. Removed UART write calls and instead return data via the rets array. Added input validation to check the size of the args array. Replaced response_t with enum Status.	src/helpers/device.c src/helpers/device.h
Refactored the pin manager helper functions to use a new command structure and data handling.	Replaced individual UART read calls with a single args array for command parameters. Added status return values to all functions. Removed UART write calls and instead return data via the rets array. Added input validation to check the size of the args array. Replaced response_t with enum Status.	src/registers/system/pin_manager.c src/registers/system/pin_manager.h
Refactored the sensors helper functions to use a new command structure and data handling.	Replaced individual UART read calls with a single args array for command parameters. Added status return values to all functions. Removed UART write calls and instead return data via the rets array. Added input validation to check the size of the args array. Replaced response_t with enum Status.	src/instruments/sensors.c
Refactored the CTMU register functions to use a new command structure and data handling.	Replaced individual UART read calls with a single args array for command parameters. Added status return values to all functions. Removed UART write calls and instead return data via the rets array. Added input validation to check the size of the args array. Replaced response_t with enum Status.	src/registers/converters/ctmu.c src/registers/converters/ctmu.h
Refactored the light helper functions to use a new command structure and data handling.	Replaced individual UART read calls with a single args array for command parameters. Added status return values to all functions. Removed UART write calls and instead return data via the rets array. Added input validation to check the size of the args array. Replaced response_t with enum Status.	src/helpers/light.c
Refactored the states to use a new command structure and data handling.	Replaced individual UART read calls with a single args array for command parameters. Added status return values to all functions. Removed UART write calls and instead return data via the rets array. Added input validation to check the size of the args array. Replaced response_t with enum Status.	src/states.c
Implemented a new packet handler for communication between the PSLab and the host.	Created a new packet handler for receiving commands and sending responses. Implemented functions for reading and writing data to the host. Implemented a function for exchanging data between the PSLab and the host. Added a header structure for command and response packets. Added a function for getting a command function from a command code. Added a function for flushing the UART receive buffer.	src/transport/packet_handler.c src/transport/packet_handler.h src/transport/host.c src/transport/host.h src/transport/uart2.c src/transport/uart2.h
Removed debug messages.	Removed debug messages from the SD card driver. Removed debug messages from the common commands. Removed debug files.	src/sdcard/sdcard.c src/commands.c src/helpers/CMakeLists.txt src/helpers/debug.c src/helpers/debug.h

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[sourcery-ai]

Hey @bessman - I've reviewed your changes and they look great!

Here's what I looked at during the review

• 🟡 General issues: 5 issues found
• 🟢 Security: all looks good
• 🟢 Testing: all looks good
• 🟡 Complexity: 5 issues found
• 🟢 Documentation: all looks good

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[bessman]

This is now theoretically finished. It needs to be thoroughly tested, and even when everything works as intended the communication is of course completely incompatible with the current pslab-python & pslab-android. They will need to be updated to use the new protocol, and then new releases need to be synchronized.

[bessman]

This requires further testing, but I need it for tomorrow's workshop so here goes.