chacon-rpi/emit/emitlib.c

#include <stdio.h>
#include <unistd.h>
#include <malloc.h>
#include "emitlib.h"


unsigned int timings[4][2] = {
    {250, 250},  //  bit 0
    {250, 1200}, //  bit 1
    {250, 2600}, //  start of frame
    {250, 9900}  //  end of data
};

unsigned char numbering[4] = {0x05, 0x06, 0x09, 0x0A};

/**
 * Create a new buffer
 *
 * @return the created buffer
 */
BUFFER createBuffer()
{
    BUFFER buffer;
    buffer.byteSize = 1;
    buffer.bitSize = 0;
    buffer.data = (char*) malloc(1);
    buffer.data[0] = 0;
    return buffer;
}

/**
 * Release the memory
 *
 * @param buffer the buffer to destroy
 */
void destroyBuffer(BUFFER buffer)
{
    free(buffer.data);
}

/**
 * Print all the bits from a buffer
 *
 * @param buffer the buffer holding the data
 */
void printfBinaryBuffer(BUFFER buffer)
{
    printf("bytes: %d\nbits: %d\n", buffer.byteSize, buffer.bitSize);
    unsigned char byte;
    unsigned char bit;
    unsigned int x;
    int i;
    for(x=0; x<buffer.byteSize; x++) {
        byte = buffer.data[x];
        for(i=0x80; i>0; i>>=1) {
            if ((bit==0) && (byte & i)) {
                fprintf(stdout, "\n");
            }
            bit = ((byte & i) == i);
            fprintf(stdout, "%d", bit);
        }
    }
}

/**
 * Push a bit in a buffer
 *
 * @param buffer the buffer holding the data
 * @param bit the bit to push
 */
void pushBit(BUFFER* buffer, unsigned char bit)
{
    buffer->data[buffer->byteSize-1] |= bit << (7-buffer->bitSize);
    buffer->bitSize++;
    if (buffer->bitSize == 8) {
        buffer->bitSize = 0;
        buffer->byteSize++;
        buffer->data = (char*)realloc(buffer->data, buffer->byteSize);
        buffer->data[buffer->byteSize-1] = 0;
    }
}

/**
 * Append a bit that will be emitted for a specific time
 *
 * @param buffer the buffer holding the data
 * @param bit the bit to push
 * @param usec time in µs
 * @param clock frequency
 */
void appendBit(BUFFER* buffer, unsigned char bit, unsigned int usec, unsigned int freq)
{
    unsigned int i;
    for(i=0; i<(usec * freq) / 1e6; i++) {
        pushBit(buffer, bit);
    }
}

/**
 * Append data according to Chacon protocole
 *
 * @param buffer the buffer holding the data
 * @param type data type (BIT0 | BIT1 | START_OF_FRAME | END_OF_DATA)
 * @param clock frequency
 */
void appendData(BUFFER* buffer, unsigned int type, unsigned int freq)
{
    appendBit(buffer, 1, timings[type][0], freq);
    appendBit(buffer, 0, timings[type][1], freq);
}

/**
 * Append a byte according to Chacon protocole
 *
 * @param buffer the buffer holding the data
 * @param byte the byte to append
 * @param clock frequency
 */
void appendByte(BUFFER* buffer, unsigned char byte, unsigned int freq)
{
    int i;
    for(i=0x80; i>0; i>>=1) {
        appendData(buffer, ((byte & i) == i), freq);
    }
    printf("%02X ", byte);
}


/**
 * Append a complete command according to Chacon protocole
 *
 * @param buffer the buffer holding the data
 * @param id command id (refer to your remote)
 * @param section button section (0:A, 1:B, 2:C, 3:D)
 * @param nb button number(1, 2, 3, 4)
 * @param on boolean for on/off
 * @param global if true G button is selected (nb will be ignore)
 * @param clock frequency
 */
void pushCode(BUFFER* buffer, unsigned char* id, unsigned char section, unsigned char nb, unsigned char on, unsigned char global, unsigned int freq)
{
    unsigned char byte6 = (id[6] & 0xf0) + numbering[on + (global ? 2 : 0)];
    unsigned char byte7 = (numbering[section] << 4) + numbering[nb];
    unsigned int i;
    if (global) {
        byte7 = 0x55;
    }
    appendData(buffer, START_OF_FRAME, freq);
    printf("SOF ");
    for(i=0; i<6; i++) {
            appendByte(buffer, id[i], freq);
    }
    appendByte(buffer, byte6, freq);
    appendByte(buffer, byte7, freq);
    appendData(buffer, END_OF_DATA, freq);
    printf("EOD ");
}