112 lines
3.1 KiB
C++
112 lines
3.1 KiB
C++
#include "Arduino.h"
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#define INPUTS 8
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byte touchOut=0; //binary encoded sensors
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uint16_t rawIn[INPUTS];
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uint16_t countedLow[INPUTS]; //count the times input was below threshold (touched)
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#define TOUCHTHRESHOLD 1000 //below which value input counts as touched. 0<x<1024
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#define COUNTEDLOWTHRESHOLD 10 //how many times input has to be sampled as low in a row to count as real touch.
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#define COUNTEDLOWTHRESHOLD_OFF 0
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// Inputdelay is given by: COUNTEDLOWTHRESHOLD*ADCREADINTERVAL
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unsigned long last_adcmicros=0;
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#define ADCREADINTERVAL 2000 //in microseconds. interval to read all adc values
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boolean last_output[INPUTS];
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unsigned long last_send=0;
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#define MINIMUMSENDDELAY 10 //in milliseconds. minimum delay between serial sends
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void setup() {
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pinMode(LED_BUILTIN, OUTPUT);
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digitalWrite(LED_BUILTIN, LOW);
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pinMode(A0, INPUT_PULLUP);
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pinMode(A1, INPUT_PULLUP);
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pinMode(A2, INPUT_PULLUP);
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pinMode(A3, INPUT_PULLUP);
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pinMode(A4, INPUT_PULLUP);
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pinMode(A5, INPUT_PULLUP);
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pinMode(A6, INPUT_PULLUP);
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pinMode(A7, INPUT_PULLUP);
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Serial.begin(115200);
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}
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void loop() {
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unsigned long loopmillis=millis();
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// ## Sampling and Touch Filtering ##
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if (micros()-last_adcmicros>=ADCREADINTERVAL)
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{
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last_adcmicros=micros();
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//Sample all analog Inputs
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rawIn[0]=analogRead(A0);
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rawIn[1]=analogRead(A1);
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rawIn[2]=analogRead(A2);
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rawIn[3]=analogRead(A3);
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rawIn[4]=analogRead(A4);
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rawIn[5]=analogRead(A5);
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rawIn[6]=analogRead(A6);
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rawIn[7]=analogRead(A7);
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//Serial.print(analogRead(A1));
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//Serial.print(": ");
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//Serial.println(micros()-mic);
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/*
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Serial.print(rawIn[0]);
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Serial.print(", ");
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Serial.print(rawIn[1]);
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Serial.println();*/
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for (uint8_t i=0;i<INPUTS;i++){ //for all inputs
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if (rawIn[i]<=TOUCHTHRESHOLD) { //touch detected (input low at this sample)
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countedLow[i]++; //increase counter
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if (countedLow[i]>=COUNTEDLOWTHRESHOLD) { //upper limit
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countedLow[i]=COUNTEDLOWTHRESHOLD; //upper limit. prevent overflow
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}
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}else{ //released or not pressed hard enough
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if (countedLow[i]>0) {
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countedLow[i]--; //decrease counter
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}
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}
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}
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//Serial.print("A0="); Serial.println(rawIn[0]);
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}
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for (uint8_t i=0;i<INPUTS;i++){ //for all keys
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if (countedLow[i]>=COUNTEDLOWTHRESHOLD) { //key pressed/touched
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last_output[i]=true;
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}else if (countedLow[i]<=COUNTEDLOWTHRESHOLD_OFF) { //key pressed/touched
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last_output[i]=false;
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}
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}
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// ## Calculate Byte ##
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byte newTouch=0;
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for (uint8_t i=0;i<INPUTS;i++){ //for all keys
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if (last_output[i]) { //key pressed/touched
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newTouch^=1<<i;
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}
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}
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digitalWrite(LED_BUILTIN, newTouch!=0); //Show touch on led
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// ## Send to Raspberry ##
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if (loopmillis-last_send>MINIMUMSENDDELAY) //delay between last send long enough
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{
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if (newTouch!=touchOut) { //touched keys have changed
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touchOut=newTouch; //update
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last_send=loopmillis;
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//Serial.println(touchOut, BIN); //Debug output
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Serial.write(touchOut); //Send byte
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}
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}
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}
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