Lichtsensoren Auswerten

**radbruch** · 21.06.2012, 17:29

Hallo

Mal aus der Hüfte geschossen: adcLSL wird durch das Tasksystem mit dem Helligkeitswert geladen:

Code:

/**
 * This functions checks all ADC channels sequentially in the Background!
 * It can save a lot of time, if the ADC channels are checked like this, because
 * each A/D conversion takes some time. With this function you don't need to
 * wait until the A/D conversion is finished and you can do other things in the 
 * meanwhile.
 * If you use this function (this is also the case if you use task_RP6System 
 * because it calls this function), you can NOT use readADC anymore!
 *
 * Instead you can use the seven global variables you see above to
 * get the ADC values!
 */
void task_ADC(void)
{
	static uint8_t current_adc_channel = 0;
	if(!(ADCSRA & (1<<ADSC))) {
	//	ADCSRA |= (1<<ADIF);
		switch(current_adc_channel) {
			case 0: adcBat = ADC; startADC(ADC_MCURRENT_L); break;
			case 1: adcMotorCurrentLeft = ADC; startADC(ADC_MCURRENT_R); break;
			case 2: adcMotorCurrentRight = ADC; startADC(ADC_LS_L); break;
			case 3: adcLSL = ADC; startADC(ADC_LS_R); break;
			case 4: adcLSR = ADC; startADC(ADC_ADC0); break;
			case 5: adc0 = ADC; startADC(ADC_ADC1); break;
			case 6: adc1 = ADC; startADC(ADC_BAT); break;
		}
		if(current_adc_channel == 6)
			current_adc_channel = 0;
		else
			current_adc_channel++;
	}
}

Wenn du das Tasksystem vorerst nicht verwenden möchtest, dann kannst du die Werte auch mit readADC() ermitteln:

Code:

/*****************************************************************************/
// ADC:

/**
 * Read ADC channel (10 bit -> result is an integer from 0 to 1023).
 * The channels (ADC_BAT etc.) are defined in the RP6RobotBase.h file!
 *
 * This is a blocking function, which means it waits until the conversion
 * is complete. There is a more complicated alternative that frequently 
 * checks all channels (s. below).
 *
 * This function returns 0 if the ADC is buisy! This has been done to
 * prevents problems when the automatical function is used.
 * You should usually NOT use this function if you use the automatic one!
 *
 * Example:
 *
 *			uint16_t uBat = readADC(ADC_BAT);
 *			if(uBat < 600)
 *				writeString("WARNING: BAT IS LOW!\n");
 *
 */
uint16_t readADC(uint8_t channel)
{
	if((ADCSRA & (1<<ADSC))) return 0; // check if ADC is buisy...
	ADMUX = (1<<REFS0) | (0<<REFS1) | (channel<<MUX0);
	ADCSRA = (0<<ADIE) | (1<<ADSC) | (1<<ADEN) | (1<<ADPS2) | (1<<ADPS1) | (1<<ADIF);
	while ((ADCSRA & (1<<ADSC))); 
	ADCSRA |= (1<<ADIF);
	return ADC;
}

(Beide Funktionen sind aus RP6RobotBaseLib.c)

Die Kanäle werden in RP6RobotBase.h definiert:

Code:

#define ADC_BAT 			7
#define ADC_MCURRENT_L 		6
#define ADC_MCURRENT_R 		5
#define ADC_LS_L 			3
#define ADC_LS_R 			2
#define ADC_ADC1 			1
#define ADC_ADC0 			0

Gruß

mic

**petzi--** · 21.06.2012, 20:35

Danke für die vielen Antworten

,
Ich hab das Problem jetzt so gelöst:

#include "RP6RobotBaseLib.h"

int main(void)
{
initRobotBase();
powerON();

while(true)
{
task_RP6System();

if(adcLSL>=520)
{
setLEDs(0b000000);
}

else
{
setLEDs(0b000100);
}
}

return 0;
}

Gruß,
petzi--