File content as of revision 1:bb881a434906:

/****************************** RC5 Decoder  and Preamp Controller V1.0 *************************/
/*                                  AndrewR written in 2015                                     */
/* This RC5 decoder works by reading in the RC5 stream from one of the serial port lines        */
/* and saving the incoming stream into  an array called stream, after which it is decoded and   */
/* the command executed. A Marantz RC-68PM IR R/C was used to develop this program - it         */
/* should work with any controller complying with the Philips RC5 standard.                     */
/* See the rc5codes.h header for the codes used.                                                */

/* The following audio preamplifier facilities  are catered for:-                               */
/* 1. Manual volume control adjustment via ALPS RK27 motorized potentiometer                    */
/* 2. Input select via rotary encoder                                                           */
/* 3. Output mute via push button actuation                                                     */
/* 4. Record loop via push button actuation                                                     */
/* 5. Power ON output to drive the /standby input of a system power supply                      */
/* Facilities 1,2,3 and 5 are supported by an RC5 compliant remote control for preamplifiers    */
/* The program can be used with either the LPC11U24 or the LPC1114 - just use the appropriate   */
/* Pindfefxxxx.h file                                                                           */

#include "mbed.h"
#include "rc5codes.h"      // Philips RC5 code definitions
#include "Pindef1114.h"    // all microcontroller I/O pin assignments defined here    

#define TRUE 1
#define FALSE 0
#define HIGH 1
#define LOW 0
#define rc5_bitcount 14     // number of RC5 bits
#define tick 444            // quarter bit time in us
#define tock  1778          // one bit time in us
#define VUP_timeout 10      // defines max number of R/C cycles before the vol ctrl mtr drive stops
#define VDWN_timeout 10     // as above but for volume decrease. Needed to ensure the motor is not burnt out

//#define PHONO_IN 1        // these are the input assignments - not used in V1.0 of the
//#define CD_IN 2           // controller since the input select is just stepped
//#define TUN_IN 4          // through from PHONO_IN to REC_IN and back again
//#define AUX1_IN 8
//#define MSERV_IN 16
//define REC_IN 32

int startbit;
int toggle;
int toggle1;
int toggle2;
int standby;
int address;
int command;

int FLAG1;                  // this is used in the remote control input processing
int FLAG2;                  // this is used in the select input processing
int FLAG3;                  // this is for the mute pushbutton
int FLAG4;                  // this is for the standby pushbutton
int FLAG5;                  // this is the recloop flag
int RCFLAG = FALSE;         // used to determine if the select command came via R/C
int standbyflag;            // used to save the standby condition

int relay;
int key_press = 1;          // keeps track of key presses
int toggle_press = 1;       //stores value of toggle for key_press routine

// delcarations below are all for the input select proceses
int select = 0;
int select_save = 1;        // we save the status of select drive here. Initial value is 1
int select_rot = 1;         // rotary encoder pulse counter

// declare function prototypes here
void select_out (void);
void rc5isr(void);
void mute_isr(void);
void recloop_isr(void);
void select_isr(void);
void standby_out(void);

/****************************** volume increase ***********************************/
void vol_up (void)
{
    if ((standbyflag == TRUE) && (key_press < VUP_timeout)) {

        FWD1 = HIGH;
  //      FWD2 = HIGH;
        wait(.1);           //drive the motors for a short while
        FWD1 = LOW;
  //      FWD2 = LOW;
    }
    if (toggle1 != toggle) {
        key_press = 0;      // user released the button, so reset counter
    } else if (toggle1 == toggle) {
        key_press++;        // button remained depressed, so increment counter
    }
    toggle1 = toggle;
    wait_ms(1);
}

/******************************* volume decrease **********************************/
void vol_dwn (void)
{
    if ((standbyflag == TRUE) && (key_press < VDWN_timeout)) {

        REV1 = HIGH;
 //       REV2 = HIGH;
        wait(.1);           //drive the motors for a short while
        REV1 = LOW;
 //       REV2 = LOW;
    }
    if (toggle1 != toggle) {
        key_press = 0;      // user released the button, so reset counter
    } else if (toggle1 == toggle) {
        key_press++;        // button remained depressed, so increment counter
    }
    toggle1 = toggle;
    wait_ms(1);
}
/********************************** stdby_isr *************************************/
void stdby_isr (void)
{
    FLAG4 = TRUE;
}

/*********************************** standby **************************************/
/* this will require supporting hardware functionality to power down the          */
/* analog board, LED's etc. Best option here is to use regulators with a          */
/* shutdown option. for now,  all the LED's are just turned off.                  */

void standby_out(void)      // both p/button and R/C come in here
{
    stdby_int.fall(NULL);   // on first power up cycle NO interuppts are accepted
                    // and neither any while this function is executed in any case
    wait_ms(20);            // a very simple debounce
    do {                    // that waits for the depressed button to be released
        (1);
    } while (stdby !=1);

    if (standbyflag == TRUE) {      // was ON so we will turn it OFF
        // turn off all interrupts except the standby and rc5int
        select_int.fall(NULL);
        mute_int.fall(NULL);
        recloop_int.fall(NULL);
        muteind = LOW;
        muteout = LOW;
        recloop_out = LOW;
        select_save = select_drv;       // save the status of select_drv
        select_drv = 0;                 // turn all input select realys OFF
        //power_ind = LOW;                // this is the regulator shutdown control.  HIGH = ON
        wait(1);
        muteind = HIGH;`
        standbyflag = FALSE;            // set it up for the next power cycle

    } else if (standbyflag == FALSE) {  // was OFF so we will turn it ON
        //printf("i should be here!\n");
        //power_ind = HIGH;
        muteind = LOW;
        rc5int.rise(&rc5isr);           // trigger int on rising edge - go service it at rc5dat
        select_int.fall(&select_isr);   // input from rotary encoder or input select
        mute_int.fall(&mute_isr);
        recloop_int.fall(&recloop_isr);
        wait(2);
        select_drv = select_save;       // recall the input select setting
        wait(2); 
        muteind = HIGH;                       // let things settle a bit
        muteout = HIGH;
        standbyflag = TRUE;

    }
    //printf("STDB ISR\n");
    wait_ms(5);
    stdby_int.fall(&stdby_isr);         // re-enable the standby interrupt
}

/********************************** record loop isr *******************************/

void recloop_isr(void)
{
    FLAG5 = TRUE;
}
/************************** recloop - just a simple toggle ************************/
void recloop()
{
    recloop_int.fall(NULL);             // to prevent re-entrance when coming here from the R/C
    wait_ms(20);                        // simple debounce for when mute is via the f/p p/b switch
    do {
        (1);                            // wait here until the button is released
    } while (recloop_in!=1);
    recloop_out = !recloop_out;
    wait_ms(20);
    recloop_int.fall(&recloop_isr);
}

/************************************ mute_isr ************************************/

void mute_isr(void)
{
    FLAG3 = TRUE;
    toggle2 = !toggle2;                 // so the p/button input is recognized in mute_out()
    if(muteout = HIGH)
        {muteind = LOW;}
}
/*************************** mute - just a simple toggle **************************/
void mute_out()
{
    mute_int.fall(NULL);                // to prevent re-entance when coming here from the R/C
    if ((standbyflag == TRUE) && (toggle != toggle2)) { // only toggle mute if the preamp is ON
        wait_ms(20);                    //simple debounce for when mute is via the f/p p/b switch
        do {
            (1);                        //wait here until the button is released
        } while (mute != 1);
        muteout = !muteout;
        wait_ms(20);

    }
    toggle2 = toggle;
    mute_int.fall(&mute_isr);
}

/************************************ rc5isr **************************************/
/* Interrupt triggered by a rising edge on p21 of the cont  which is R/C data in  */

void rc5isr(void)
{
    FLAG1 = TRUE;
}
/***************** save rc5 bit stream from remote controller *********************/
/* This function reads the input data on pin rc5dat at 1778us ('tock')intervals   */
/* and saves the data into an array stream[i].                                    */
/* This function only looks at the second half of the bit position, since if that */
/* is a 1 then it is assumed the first half of the bit position is a zero. Note   */
/* that in Manchester encoding, you cannot (should not) have both the 0 half-bit  */
/* position and the 1 half-bit position both HIGH  or LOW in the same bit time -  */
/* a simplification exploited in this function.                                   */

void save_stream(void)
{
    bool stream[15];// the array is initialized each time its used and is local only
    int bitloop;    // number of bit positions
    int i = 0;      // counter
    int k = 0;      // temp storage
    startbit = 0;
    address = 0;
    command = 0;
    toggle = 0;
    wait_us(tick);     // locate read point in middle of 1st half bit time of the 1st start bit
    for (bitloop = 0; bitloop <15; bitloop++) {
        stream[bitloop] = rc5dat;  //read the data and save it to array position [i]
        wait_us(tock); //wait here until ready to read the next bit in
        
        // now have 14 bits loaded into stream[i]
    }
    /* now put data in the array into the start, toggle, address and command variables - array counts from stream[0] */

    for (i=0; i<2; i++) {   // first 2 bit positions are start bits = 3; will use this later for basic error checking
        k = stream[i];
        startbit = (startbit << 1);
        startbit = startbit|k;
    }

    toggle = stream[2];             // 3rd bit position is the toggle bit - 1 bit

    for (i = 3; i <8; i++) {        // bit positions 3 to 7 are the address (or 'system') - 5 bit positions in total
        k = stream[i];
        address = (address << 1);
        address = address|k;
    }

    for (i = 8; i <14; i++) {   // bit positions 8 to 13 are the command - 6 bit positions
        k = stream[i];
        command = (command << 1);
        command = command|k;
    }

}
/********************************* process_stream() *******************************/
/* handles commands coming in from the remote controller only                     */

void process_stream (void)
{
    if ((address == PREAMP) && (startbit == 3)) {
// basic error checking - must be preamp + startbit ok to get executed otherwise skip completly
        switch (command) {

            case VUP:
                vol_up();
                break;

            case VDOWN:
                vol_dwn();
                break;

            case MUTE:
                mute_out();
                break;

            case SELECT_R:
                select_out();
                break;

            case STANDBY:
                standby_out();
                break;
        }
    }
}
/*********************************** select_isr ***********************************/

void select_isr(void)
{
    FLAG2 = TRUE;
}

/********************************* select_process *********************************/
/* used for selecting the input source.  This function is used by both the        */
/* rotary encoder and the remote control                                         */

void select_process(void)
{
    if (RCFLAG == FALSE) {  // if used R/C skip to select below
        wait_ms(5); // debounce
        select = 0; // flush select

        select = (select | sela) <<1; // read the two port lines associated with the select rotary encoder
        select = (select | selb);
    }

    switch (select) {           
        case 1:                 // select encoder is being rotated CW
            select_rot <<= 1;
            if (select_rot > 32) {
                select_rot = 1;
            }
            break;

        case 0:
            select_rot >>= 1;   // encoder is being rotated CCW
            if (select_rot < 1) {
                select_rot = 32;
            }
            break;

        case 2:
        {} break;               // indeterminate fall through values - ignore
        case 3:
        {} break;
    }
    
    select_drv = select_rot;    // write the value out to the bus
}


/********************* input select from remote controller only *******************/
void select_out (void)
{
    if (toggle != toggle1) {    // if the R/C button is held down, skip the increment
        RCFLAG = TRUE;          // this indicates command came in through the remote
        select = 1;
        select_process();
        RCFLAG = FALSE;
    }
    toggle1 = toggle;
}
/************************************ main() ***************************************/
int main(void)
{
    disable_irq();                    // just to make sure we can set up correctly without problems
    
    muteind = LOW;
    muteout = LOW;                      // mute the output while we go through  power-up sequence
    recloop_out = LOW;                  // make sure initial recloop condition is delected
    //power_ind = LOW;                    // power control; HIGH = power up
    wait(.2);
    //Serial pc(USBTX, USBRX);            // for debuging only - comment out on production
    FLAG1 = FALSE;
    FLAG2 = FALSE;
    FWD1=0;
  //  FWD2=0;
    REV1=0;
  //  REV2=0;                            //make sure the volume control motor is OFF

                                        // set up the ISR's we will be using
    rc5int.rise(&rc5isr);               // trigger int on rising edge - go service it at rc5dat
    select_int.fall(&select_isr);       // input from rotary encoder or input select
    mute_int.fall(&mute_isr);           // mute push button interrupt
    recloop_int.fall(&recloop_isr);     // record loop push button interrupt
    stdby_int.fall(&stdby_isr);         // the system power/standby switch

    //now disable them, leaving only the stand by p/button and rc5int interrupts active
    select_int.fall(NULL);
    mute_int.fall(NULL);
    recloop_int.fall(NULL);

//printf("diable ISR\n");

    standbyflag = TRUE;                 // preamp will be set-up first time for OFF
    standby_out();                      // go through standby_out for initial set-up
    select_save = 2;                    // CD will be selected when power is first turned on
    muteind = HIGH;                    
    __enable_irq();


    // all ready and in standby from this point forward

LOOP:                                   // this is the main operating loop
//printf("WFI\n");
    __WFI();                            // wait here until interrupt

    if (FLAG1 == TRUE) {                // FLAG1 indicates remote control was used
        __disable_irq();
        save_stream();
        if (startbit == 3) {
            process_stream();
        }
        FLAG1 = FALSE;
        __enable_irq();
    }

    if (FLAG2 == TRUE) {
        __disable_irq();
        select_process();               //select process
        FLAG2 = FALSE;
        __enable_irq();
    }

    if (FLAG3 == TRUE) {
        __disable_irq();
        mute_out();                     //mute
        FLAG3 = FALSE;
        __enable_irq();
    }
//printf("B4stdby\n");
    if (FLAG4 == TRUE) {
        __disable_irq();
        standby_out(); 
                                        // standby
        FLAG4 = FALSE;
// printf("back from isr\n"); 
        __enable_irq();
        //printf("renable isr\n");   
    }
//printf("finished with STBY\n");
    if (FLAG5 == TRUE) {
        __disable_irq();
        recloop();                      //recloop
        FLAG5 = FALSE;
        __enable_irq();
    }

    wait_us(5);
//printf("loop to WFI\n");
    goto LOOP;

}