Code:
/* 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]);
}
}
/* ------------------------------------------------------------------------- */
;