Objective Development Forums

Code: Select all

/* Name: main.c
 * Project: custom-class, a basic USB example
 * Author: Christian Starkjohann
 * Creation Date: 2008-04-09
 * Tabsize: 4
 * Copyright: (c) 2008 by OBJECTIVE DEVELOPMENT Software GmbH
 * License: GNU GPL v2 (see License.txt), GNU GPL v3 or proprietary (CommercialLicense.txt)
 * This Revision: $Id: main.c 790 2010-05-30 21:00:26Z cs $
 */

/*
This example should run on most AVRs with only little changes. No special
hardware resources except INT0 are used. You may have to change usbconfig.h for
different I/O pins for USB. Please note that USB D+ must be the INT0 pin, or
at least be connected to INT0 as well.
We assume that an LED is connected to port B bit 0. If you connect it to a
different port or bit, change the macros below:
*/

#include <avr/eeprom.h>
#include <avr/io.h>
#include <avr/wdt.h>
#include <avr/interrupt.h>  /* for sei() */
#include <util/delay.h>     /* for _delay_ms() */

#include <avr/pgmspace.h>   /* required by usbdrv.h */
#include "usbdrv.h"
#include "oddebug.h"        /* This is also an example for using debug macros */
#include "requests.h"       /* The custom request numbers we use */

#include "lcd.h"

#ifndef EEMEM
// alle Textstellen EEMEM im Quellcode durch __attribute__ ... ersetzen
#define EEMEM  __attribute__ ((section (".eeprom")))
#endif
 
/* bitmask of detected lcd controllers */
uchar controller = 0;

/* ------------------------------------------------------------------------- */
/* PWM units are used for contrast and backlight brightness */

/* contrast and brightness are stored in eeprom */
uchar eeprom_valid EEMEM;
uchar eeprom_contrast EEMEM;
uchar eeprom_brightness EEMEM;

static uchar buffer[512];
static uchar currentPosition, bytesRemaining;

struct {
  uchar report_id;
  unsigned short offset;
  uchar len;
} cmd_state;


void pwm_init(void) {

  /* check if eeprom is valid and set default values if not */
  /* initial values: full contrast and full brightness */
  if(eeprom_read_byte(&eeprom_valid) != 0x42) {

    /* write magic "eeprom is valid" marker 0x42 and default values */
    eeprom_write_byte(&eeprom_valid, 0x42);
    eeprom_write_byte(&eeprom_contrast, 0xff);
    eeprom_write_byte(&eeprom_brightness, 0xff);
  }

  /* PortB: set DDB1 and DDB2 => PORTB1 and PORTB2 are output */
  DDRB |= _BV(1) | _BV(2);
 
  /* Set Timer1:
    - Fast PWM,8bit => Mode 5 (WGM13=0,WGM12=1,WGM11=0,WGM10=1)
    - Output-Mode: lower voltage is higher contrast
      => Set OC1A on Compare Match, clear OC1A at BOTTOM, (inverting mode)
    COM1A1=1,COM1A0=1
    higher voltage is higher brightness
      => Clear OC1B on Compare Match, set OC1B at BOTTOM, (non-inverting mode)
    COM1B1=1,COM1B0=0
    - Timer runs at inernal clock with no prescaling => CS12=0,CS11=0,CS10=1
  */
  TCCR1A = _BV(COM1A1) | _BV(COM1A0) | _BV(COM1B1) | _BV(WGM10);
  TCCR1B = _BV(WGM12) | _BV(CS10);

  TIMSK &=( (~_BV(2)) & (~_BV(3)) & (~_BV(4)) & (~_BV(5)));

  OCR1A = eeprom_read_byte(&eeprom_contrast);
  OCR1B = eeprom_read_byte(&eeprom_brightness);
}

void set_contrast(uchar value) {
  /* store value in eeprom if it actually changed */
  if(value != eeprom_read_byte(&eeprom_contrast))
    eeprom_write_byte(&eeprom_contrast, value);

  OCR1A = value;  // lower voltage is higher contrast
}

void set_brightness(uchar value) {
  /* store value in eeprom if it actually changed */
  if(value != eeprom_read_byte(&eeprom_brightness))
    eeprom_write_byte(&eeprom_brightness, value);

  OCR1B = value;  // higher voltage is higher brightness
}



/* ------------------------------------------------------------------------- */
/* ----------------------------- USB interface ----------------------------- */
/* ------------------------------------------------------------------------- */

usbMsgLen_t usbFunctionSetup(uchar data[8])
{
usbRequest_t    *rq = (void *)data;
static uchar    dataBuffer[4];  /* buffer must stay valid when usbFunctionSetup returns */


    if(rq->bRequest == CUSTOM_RQ_ECHO){ /* echo -- used for reliability tests */
        dataBuffer[0] = rq->wValue.bytes[0];
        dataBuffer[1] = rq->wValue.bytes[1];
        dataBuffer[2] = rq->wIndex.bytes[0];
        dataBuffer[3] = rq->wIndex.bytes[1];
        usbMsgPtr = dataBuffer;         /* tell the driver which data to return */
        return 4;
    }

   if(rq->bRequest == 1){
      currentPosition = 0;                // initialize position index
          lcd_clrscr(LCD_CTRL_0);
        lcd_puts(LCD_CTRL_0, "start ");


      bytesRemaining = rq->wLength.word;  // store the amount of data requested
        if(bytesRemaining > sizeof(buffer)) // limit to buffer size
            bytesRemaining = sizeof(buffer);
        return USB_NO_MSG;        // tell driver to use usbFunctionWrite()   
      }

   if(rq->bRequest == 2){
      lcd_clrscr (LCD_CTRL_0);
        return 0;        // tell driver to use usbFunctionWrite()   
      }

    return 0x00;   /* default for not implemented requests: return no data back to host */
}


uchar usbFunctionWrite(uchar *data, uchar len)
{
    uchar i;
 
   if(len > bytesRemaining)            // if this is the last incomplete chunk
       len = bytesRemaining;               // limit to the amount we can store


   lcd_puts(LCD_CTRL_0, ".");   

    bytesRemaining -= len;
    for(i = 0; i < len; i++)
        buffer[currentPosition++] = data[i];

   if (bytesRemaining ==0)
   lcd_puts(LCD_CTRL_0, " stop");   

   return bytesRemaining == 0;             // return 1 if we have all data


      

}






/* ------------------------------------------------------------------------- */

int __attribute__((noreturn)) main(void)
{
uchar   i;

    wdt_enable(WDTO_1S);
    /* Even if you don't use the watchdog, turn it off here. On newer devices,
     * the status of the watchdog (on/off, period) is PRESERVED OVER RESET!
     */
    /* RESET status: all port bits are inputs without pull-up.
     * That's the way we need D+ and D-. Therefore we don't need any
     * additional hardware initialization.
     */
    odDebugInit();
    DBG1(0x00, 0, 0);       /* debug output: main starts */
    lcd_init(LCD_CTRL_0);
   usbInit();


   pwm_init();

    lcd_puts(LCD_CTRL_0, "LCD2USB v1.2");


    usbDeviceDisconnect();  /* enforce re-enumeration, do this while interrupts are disabled! */
    i = 0;
    while(--i){             /* fake USB disconnect for > 250 ms */
        wdt_reset();
        _delay_ms(1);
    }
    usbDeviceConnect();
   
    sei();
    DBG1(0x01, 0, 0);       /* debug output: main loop starts */
    for(;;){                /* main event loop */
        wdt_reset();
        usbPoll();
      set_brightness(buffer[63]);
    }
}

/* ------------------------------------------------------------------------- */