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Firmware - StormLib

What is StormLib?

To make it easier to send and receive the messages defined in the STORM 2027 Serial Specification, we created StormLib. StormLib also includes some abstractions of hardware (motors, encoders, etc.) taken from RobotLib. StormLib is subject to change once the 2027 rules release, and in future version afterwards.

Getting Started

  1. Install the Arduino IDE
  2. Install Earl's Arduino Pico library from Arduino IDE's Library Manager
  3. Install StormLib (TODO)
  4. Copy the firmware template (TODO) and change it to only care about the messages you care about (the ones your board will receive and send)

How to Add / Edit a Message

To add your own custom message, or edit/update an existing message, you will need to make changes in several locations. First, ensure your message is added/updated in the Serial Specification before writing any code. Then follow these steps:

  1. Add/update the message ID in the Message enum
  2. Below that, add/update the typedef struct for the message. Example:
      
    // ID 21
typedef struct DriveVelocityCmd {
    int16_t front_left_velocity;
    int16_t front_right_velocity;
    int16_t back_left_velocity;
    int16_t back_right_velocity;
} DriveVelocityCmd;
    Note: if you message is a command (the computer telling a PCB to do something), then add the "Cmd" suffix to the name. If it's a response (the PCB telling the computer something it asked for), then add the "Rsp" suffix to the name. Otherwise, add the "Msg" suffix to the name.
  3. Below that, in the StormMessage class, make a function that returns the struct you defined in the previous step. Example:
     
    TaskResponseRsp AsTaskResponse() {
    TaskResponseRsp rsp;

    rsp.intake_velocity = byte_to_int16(DATA);
    rsp.arm_position = static_cast<uint8_t>(DATA[2]);
    rsp.climber_position = byte_to_uint16(DATA + 3);
    rsp.charging_wheel_velocity = static_cast<uint8_t>(DATA[5]);
  
    return rsp;
}
    Note: DATA is the char (byte) array that stores the data portion of the message. You will need to cast those bytes into the data type of the variables your struct defines. This can be done using one of the functions already defined (like byte_to_int16) or using static_cast<T>(). Also note the indexing: DATA is stored as a pointer (because that's how C arrays work), so to access subsequent bytes, just add to it, as shown in the example above.

And you're done! Now you can work with the struct you defined to do things.

 // if there is a message addressed to us
    if (bus.HasMessage()) {
        // get the message
        msg = bus.GetMessage();

        // and do something diffrent based on what message it is
        switch (msg.type) {
            case DriveVelocity: {
                auto converted = msg.AsDriveVelocity();

                //TODO
                
                break;
            }
            default:
                // message doesn't concern us, don't do anything
                break;
        }
    }

 

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