Moin,
Hat schon mal jemand den TSL201 (64 X 1 LINEAR SENSOR ARRAY) mit einem
AtMega angesteuert?
Ich habe einen AtMega88 der mit dem internen Taktgenerator arbeitet
(ohne /8 Prescaler).
Den Takt des TSL201 erzeuge ich mit dem TIMER2 im Phase-Correct PWM und
den SI Impuls direkt:
1 | TCCR2A = (0 << COM2A0) | (3 << COM2B0) | ((wgm & 0x03) << WGM20);
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2 | TCCR2B = (((wgm >> 2) & 0x01) << WGM22) | (2 << CS20);
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3 | TCNT2 = 0;
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4 | OCR2A = 64;
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5 | OCR2B = 32;
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6 | TIMSK2 = 0; /* Disable all interrupts or (1 << OCIE2B)?? */
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7 | DDRD |= (1 << 3) | (1 << 2);
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8 |
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9 | /* Clear TOV1 */
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10 | TIFR2 |= (1 << TOV2);
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11 | /* Wait for TOV1 */
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12 | while ((TIFR2 & (1 << TOV2)) == 0)
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13 | ;
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14 | /* set PD2 */
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15 | PORTD |= (1 << 2);
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16 | /* Wait for TCNT2 to decrease */
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17 | do {
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18 | tcnt2 = TCNT2;
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19 | } while (TCNT2 >= tcnt2);
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20 | /* clear PD2 */
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21 | PORTD &= ~(1 << 2);
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Den ADC habe ich so initialisiert:
1 | ADMUX = (0 << REFS0) | (1 << ADLAR) | (0 << MUX0);
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2 | USART_send_hex(ADMUX); USART_Transmit('\n');
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3 | ADCSRA = (1 << ADEN) | (0 << ADSC) | (0 << ADATE) | (1 << ADIF) | (0 << ADIE) | (6 << ADPS0);
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4 | USART_send_hex(ADCSRA); USART_Transmit('\n');
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5 | DIDR0 = (1 << ADC0D);
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Dann starte ich den ADC:
1 | for (i = 0; i < 64; i++)
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2 | {
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3 | /* Clear OCF2B */
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4 | TIFR2 |= (1 << OCF2B);
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5 | /* Wait for OCF2B */
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6 | while ((TIFR2 & (1 << OCF2B)) == 0)
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7 | ;
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8 | /* start conversion */
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9 | ADCSRA |= (1 << ADSC) | (1 << ADIF);
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10 | PORTD |= (1 << 4);
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11 | /* wait for conversion to finish */
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12 | while ((ADCSRA & (1 << ADIF)) == 0)
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13 | ;
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14 | PORTD &= ~(1 << 4);
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15 | /* read converted value into array */
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16 | array[i] = ADCH;
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17 | }
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Seltsamerweise sehe ich keinen Unterschied in den Daten, egal ob der
Sensor angestrahlt oder im Dunkeln ist!
