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Classpad Dev

Serial

Serial communication functions allow for sending and receiving data through the 3Pin serial port (the small jack-like port).

The functions provided here are similar to those on the Casio fx-CG50 calculator and follow the implementations found in the libfxcg library.

Methods

Open Serial

Opens the 3-pin serial port with the specified parameters.

extern "C"
int Serial_Open(unsigned char *mode);
  • Parameters: mode - An array specifying the serial port settings.
    • mode[0]: Always 0.
    • mode[1]: Bit rate (e.g., 5 for 9600 bps).
    • mode[2]: Parity (0=none, 1=odd, 2=even).
    • mode[3]: Data length (0=8bit, 1=7bit).
    • mode[4]: Stop bits (0=1bit, 1=2bit).
    • mode[5]: Always 0.
  • Returns:
    • 0 on success.
    • 3 if already open.

See Prizm’s Serial_Open for more info.

Is Serial Open

Checks if the serial port is open.

extern "C"
int Serial_IsOpen(void);
  • Returns: 1 if the serial port is open, 0 otherwise.

Close Serial

Closes the serial port.

extern "C"
int Serial_Close(int mode);
  • Parameters: mode - The mode to close the serial port.
  • Returns: 0 on success.

Read Serial

Reads a specified number of bytes from the serial port.

extern "C"
int Serial_Read(unsigned char *out, int sz, short *count);
  • Parameters:
    • out - Pointer to the buffer to store the read data.
    • sz - Number of bytes to read.
    • count - Pointer to a variable to store the number of bytes actually read.
  • Returns: 0 on success.

Read Serial Single Byte

Reads a single byte from the serial port.

extern "C"
int Serial_ReadSingle(unsigned char *out);
  • Parameters: out - Pointer to store the read byte.
  • Returns: 0 on success.

Peek Serial

Peeks at a byte in the serial buffer without removing it.

extern "C"
int Serial_Peek(int idx, unsigned char *out);
  • Parameters:
    • idx - The index of the byte to peek at.
    • out - Pointer to store the peeked byte.
  • Returns: 0 on success.

Poll Serial RX

Polls the receive buffer for available data.

extern "C"
int Serial_PollRX(void);
  • Returns: The number of bytes available in the receive buffer.

Clear Serial RX

Clears the receive buffer.

extern "C"
int Serial_ClearRX(void);
  • Returns: 0 on success.

Write Serial

Writes a specified number of bytes to the serial port.

extern "C"
int Serial_Write(const unsigned char *buf, int count);
  • Parameters:
    • buf - Pointer to the buffer containing the data to be sent.
    • count - Number of bytes to send.
  • Returns: 0 on success.

See Prizm’s Serial_Write for more info.

Write Serial Single Byte

Writes a single byte to the serial port.

extern "C"
int Serial_WriteSingle(unsigned char x);
  • Parameters: x - The byte to be sent.
  • Returns: 0 on success.

Write Unbuffered Serial

Writes a single byte to the serial port without buffering.

extern "C"
int Serial_WriteUnbuffered(unsigned char x);
  • Parameters: x - The byte to be sent.
  • Returns: 0 on success.

Poll Serial TX

Polls the transmit buffer for space.

extern "C"
int Serial_PollTX(void);
  • Returns: The number of bytes available in the transmit buffer.

Clear Serial TX

Clears the transmit buffer.

extern "C"
int Serial_ClearTX(void);
  • Returns: 0 on success.

Usage

Opening and Closing the Serial Port

#include <sdk/os/serial.hpp>
#include <sdk/os/debug.hpp>

void example_serial_open_close() {
    unsigned char mode[6] = {0, 5, 0, 0, 0, 0}; // 9600 bps, no parity, 8 data bits, 1 stop bit
    int result = Serial_Open(mode);
    if (result == 0) {
        Debug_Printf(0,0,false,0,"Serial port opened successfully\n");
    } else if (result == 3) {
        Debug_Printf(0,0,false,0,"Serial port already open\n");
    }

    result = Serial_Close(0);
    if (result == 0) {
        Debug_Printf(0,1,false,0,"Serial port closed successfully\n");
    }
}

Sending and Receiving Data

#include <sdk/os/serial.hpp>
#include <sdk/os/debug.hpp>

void example_serial_communication() {
    unsigned char mode[6] = {0, 5, 0, 0, 0, 0}; // 9600 bps, no parity, 8 data bits, 1 stop bit
    Serial_Open(mode);

    unsigned char send_data[] = "Hello, Serial!";
    Serial_Write(send_data, sizeof(send_data));

    unsigned char recv_data[20];
    short count;
    Serial_Read(recv_data, 20, &count);

    Debug_Printf(0,0,false,0,"Received %d bytes: %s\n", count, recv_data);

    Serial_Close(0);
}