CODEWITHSUNDEEP
androidarduinobaud-rate
ilkengin
ilkengin

Reputation: 301

Changing USB Baud Rate from 9600 to 115200 on Android

I have an Arduino which sends data serially in 115200 baud rate.

There is an application that receives data from Arduino in 9600 baud rate. The code is 

    // Arduino USB serial converter setup
    // Set control line state
    mUsbConnection.controlTransfer(0x21, 0x22, 0, 0, null, 0, 0);
    // Set line encoding.
    mUsbConnection.controlTransfer(0x21, 0x20, 0, 0, getLineEncoding(9600), 7, 0);
    //mUsbConnection.controlTransfer(0x21, 0x20, 0x001A, 0, getLineEncoding(9600), 7, 0);

Then in the getLineEncoding() function 

private byte[] getLineEncoding(int baudRate) {
    final byte[] lineEncodingRequest = { (byte) 0x80, 0x25, 0x00, 0x00, 0x00, 0x00, 0x08 };
    switch (baudRate) {
    case 14400:
        lineEncodingRequest[0] = 0x40;
        lineEncodingRequest[1] = 0x38;
        break;

    case 19200:
        lineEncodingRequest[0] = 0x00;
        lineEncodingRequest[1] = 0x4B;
        break;
    }

    return lineEncodingRequest;
}

There is a switch case stracture for setting the baud rate as 9600, 14400 or 19200. But I want it to be 115200 Can anyone tell me how I can do that?

Upvotes: 2

Views: 15796

Answers (3)

mobo
mobo

Reputation: 455

A good overview of a what you can do with controlTransfer() and FTDI-Chips can be found here ftdi_sio.h.

typedef enum {
  ftdi_8U232AM_48MHz_b300 = 0x2710,
  ftdi_8U232AM_48MHz_b600 = 0x1388,
  ftdi_8U232AM_48MHz_b1200 = 0x09c4,
  ftdi_8U232AM_48MHz_b2400 = 0x04e2,
  ftdi_8U232AM_48MHz_b4800 = 0x0271,
  ftdi_8U232AM_48MHz_b9600 = 0x4138,
  ftdi_8U232AM_48MHz_b19200 = 0x809c,
  ftdi_8U232AM_48MHz_b38400 = 0xc04e,
  ftdi_8U232AM_48MHz_b57600 = 0x0034,
  ftdi_8U232AM_48MHz_b115200 = 0x001a,
  ftdi_8U232AM_48MHz_b230400 = 0x000d,
  ftdi_8U232AM_48MHz_b460800 = 0x4006,
  ftdi_8U232AM_48MHz_b921600 = 0x8003,
} FTDI_8U232AM_48MHz_baudrate_t;

Upvotes: 5

dEePU
dEePU

Reputation: 195

You can also try these.These are found from this link

conn.controlTransfer(0x40, 0, 0, 0, null, 0, 0);// reset
                    conn.controlTransfer(0x40, 0, 1, 0, null, 0, 0);// clear Rx
                    conn.controlTransfer(0x40, 0, 2, 0, null, 0, 0);// clear Tx
                    conn.controlTransfer(0x40, 0x03, 0x001A, 0, null, 0, 0);//Baud rate 115200

Baudrates:

* 0x2710 ----------------- 300
* 0x1388 ----------------- 600
* 0x09C4 ----------------- 1200
* 0x04E2 ----------------- 2400
* 0x0271 ----------------- 4800
* 0x4138 ----------------- 9600
* 0x809C ----------------- 19200
* 0xC04E ----------------- 38400
* 0x0034 ----------------- 57600
* 0x001A ----------------- 115200
* 0x000D ----------------- 230400
* 0x4006 ----------------- 460800
* 0x8003 ----------------- 921600

Upvotes: 6

epichorns
epichorns

Reputation: 1278

Here is a modified function that generalizes your function above for other baud rates:

private byte[] getLineEncoding(int baudRate) {
    final byte[] lineEncodingRequest = { (byte) 0x80, 0x25, 0x00, 0x00, 0x00, 0x00, 0x08 };
    //Get the least significant byte of baudRate, 
    //and put it in first byte of the array being sent
    lineEncodingRequest[0] = (byte)(baudRate & 0xFF);

    //Get the 2nd byte of baudRate,
    //and put it in second byte of the array being sent
    lineEncodingRequest[1] = (byte)((baudRate >> 8) & 0xFF);

    //ibid, for 3rd byte (my guess, because you need at least 3 bytes
    //to encode your 115200+ settings)
    lineEncodingRequest[2] = (byte)((baudRate >> 16) & 0xFF);

    return lineEncodingRequest;

}

Upvotes: 7

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