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51 lines
1.5 KiB
C++
51 lines
1.5 KiB
C++
#include "wiring_private.h"
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#include "pins_arduino.h"
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extern "C" int __analogRead(uint8_t pin);
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extern "C" int analogRead(uint8_t pin) {
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static uint8_t currentAin = 0;
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delay(0);
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if (pin >= ANALOG_INPUT_HARDWARE) {
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return 0;
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}
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uint8_t ain = analog_pin_to_mux_channel[pin];
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if (ain == (uint8_t)NOT_A_PIN) {
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return 0;
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}
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if (currentAin > ain) {
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for (int i = 0; i < (8 - currentAin); ++i)
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{
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digitalWrite(ANALOG_INPUT_SELECTOR_PIN, HIGH);
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digitalWrite(ANALOG_INPUT_SELECTOR_PIN, LOW);
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digitalWrite(ANALOG_INPUT_SELECTOR_PIN, HIGH);
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digitalWrite(ANALOG_INPUT_SELECTOR_PIN, LOW);
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}
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currentAin = 0;
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}
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for (int i = currentAin; i < ain; ++i)
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{
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digitalWrite(ANALOG_INPUT_SELECTOR_PIN, HIGH);
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digitalWrite(ANALOG_INPUT_SELECTOR_PIN, LOW);
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digitalWrite(ANALOG_INPUT_SELECTOR_PIN, HIGH);
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digitalWrite(ANALOG_INPUT_SELECTOR_PIN, LOW);
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}
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currentAin = ain;
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return __analogRead(ANALOG_INPUT_HARDWARE);
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}
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void initVariant() {
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// we need to reset analog mux. When ANALOG_INPUT_SELECTOR_PIN is high
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// on ~0.4 ms, mux channel is becoming 0.
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// Mux channel is swithing on back \_ front. But there is no switching
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// - rc reset is still high when ANALOG_INPUT_SELECTOR_PIN became low
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uint16_t resetDelay = 777;
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pinMode(ANALOG_INPUT_SELECTOR_PIN, OUTPUT);
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digitalWrite(ANALOG_INPUT_SELECTOR_PIN, HIGH);
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delayMicroseconds(resetDelay);
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digitalWrite(ANALOG_INPUT_SELECTOR_PIN, LOW);
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delayMicroseconds(resetDelay);
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}
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