PchButik.se

Piezo som touchpads till MPR121

Experiment. Koppla och bygg



Piezoelement limmade pÄ en 3 mm akrylpast.
Bilder pÄ knappar Àr limmade pÄ piezo-elementen.
En touch gÄr igenom bÄde papper och skyddsplast, om du vill skydda pappers bilderna.


Video.


Signalerna I2C inteface och IRQ mÄste anpassas med en nivÄ omvandlare.

Den röda kabeln till piezoelementet Àr bort klippt.

Om du inte Àr rÀdd om din sax, kan du klippa ut den form som passar dig.

Litet bibliotek till MPR121


Inte riktigt ett bibliotek, bara definitioner och exempel
https://github.com/benkuper/ArduinoProjects/blob/master/BaseCodes/MPR121/MPR121.h
BĂ„de 'main.cpp' och 'mpr121.h' kan ligga i mappen 'scr'

Definitioner för MPR121. fil: 'mpr121.h'

/*
    MPR121.h
  April 8, 2010
  by: Jim Lindblom
*/

// MPR121 Register Defines
#define MHD_R 0x2B
#define NHD_R 0x2C
#define NCL_R   0x2D
#define FDL_R 0x2E
#define MHD_F 0x2F
#define NHD_F 0x30
#define NCL_F 0x31
#define FDL_F 0x32
#define ELE0_T  0x41
#define ELE0_R  0x42
#define ELE1_T  0x43
#define ELE1_R  0x44
#define ELE2_T  0x45
#define ELE2_R  0x46
#define ELE3_T  0x47
#define ELE3_R  0x48
#define ELE4_T  0x49
#define ELE4_R  0x4A
#define ELE5_T  0x4B
#define ELE5_R  0x4C
#define ELE6_T  0x4D
#define ELE6_R  0x4E
#define ELE7_T  0x4F
#define ELE7_R  0x50
#define ELE8_T  0x51
#define ELE8_R  0x52
#define ELE9_T  0x53
#define ELE9_R  0x54
#define ELE10_T 0x55
#define ELE10_R 0x56
#define ELE11_T 0x57
#define ELE11_R 0x58
#define FIL_CFG 0x5D
#define ELE_CFG 0x5E
#define GPIO_CTRL0  0x73
#define GPIO_CTRL1  0x74
#define GPIO_DATA 0x75
#define GPIO_DIR  0x76
#define GPIO_EN   0x77
#define GPIO_SET  0x78
#define GPIO_CLEAR  0x79
#define GPIO_TOGGLE 0x7A
#define ATO_CFG0  0x7B
#define ATO_CFGU  0x7D
#define ATO_CFGL  0x7E
#define ATO_CFGT  0x7F


// Global Constants
#define TOU_THRESH  0x06
#define REL_THRESH  0x0A


Modifierat exempel

Modifierad kod frÄn exempel för att passa knpparna och lysdioden.
Piezo elementen Àr kopplade till MPR121 pÄ pinnar 5 och 7.
Lysdiod med motstÄnd Àr kopplat till nano pÄ pinne 9 och GND.

Modifierad kod. Alternativ för fil: 'main.cpp'

#include <Arduino.h>
#include <Wire.h>
#include "mpr121.h"
//Modifierad exempel-kod frÄn biblioteket.

void mpr121_setup(void);
void readTouchInputs();
void set_register(int address, unsigned char r, unsigned char v);
boolean checkInterrupt(void);

int irqpin = 2;  // Digital 2
int LEDpin = 9;  // Digital 9
boolean touchStates[12]; //to keep track of the previous touch states

void setup(){
  pinMode(irqpin, INPUT);
  digitalWrite(irqpin, HIGH); //enable pullup resistor
  
  pinMode(LEDpin, OUTPUT);
  digitalWrite(LEDpin, LOW);

  Serial.begin(9600);
  Wire.begin();

  mpr121_setup();
}

void loop(){
  readTouchInputs();
}


void readTouchInputs(){
  if(!checkInterrupt()){
    
    //read the touch state from the MPR121
    Wire.requestFrom(0x5A,2); 
    
    byte LSB = Wire.read();
    byte MSB = Wire.read();
    
    uint16_t touched = ((MSB << 8) | LSB); //16bits that make up the touch states

    for (int i=0; i < 12; i++){  // Check what electrodes were pressed
      if(touched & (1<<i)){
      
        if(touchStates[i] == 0){
          //pin i was just touched
          Serial.print("pin ");
          Serial.print(i);
          Serial.println(" was just touched");

          if (i == 5) {
            digitalWrite(LEDpin, HIGH);
          }
          
          if (i == 7) {
            digitalWrite(LEDpin, LOW);
          }

        }else if(touchStates[i] == 1){
          //pin i is still being touched
        }  
      
        touchStates[i] = 1;      
      }else{
        if(touchStates[i] == 1){
          Serial.print("pin ");
          Serial.print(i);
          Serial.println(" is no longer being touched");
          
          //pin i is no longer being touched
       }
        
        touchStates[i] = 0;
      }
    
    }
    
  }
}

void mpr121_setup(void){

  set_register(0x5A, ELE_CFG, 0x00); 
  
  // Section A - Controls filtering when data is > baseline.
  set_register(0x5A, MHD_R, 0x01);
  set_register(0x5A, NHD_R, 0x01);
  set_register(0x5A, NCL_R, 0x00);
  set_register(0x5A, FDL_R, 0x00);

  // Section B - Controls filtering when data is < baseline.
  set_register(0x5A, MHD_F, 0x01);
  set_register(0x5A, NHD_F, 0x01);
  set_register(0x5A, NCL_F, 0xFF);
  set_register(0x5A, FDL_F, 0x02);
  
  // Section C - Sets touch and release thresholds for each electrode
  set_register(0x5A, ELE0_T, TOU_THRESH);
  set_register(0x5A, ELE0_R, REL_THRESH);
 
  set_register(0x5A, ELE1_T, TOU_THRESH);
  set_register(0x5A, ELE1_R, REL_THRESH);
  
  set_register(0x5A, ELE2_T, TOU_THRESH);
  set_register(0x5A, ELE2_R, REL_THRESH);
  
  set_register(0x5A, ELE3_T, TOU_THRESH);
  set_register(0x5A, ELE3_R, REL_THRESH);
  
  set_register(0x5A, ELE4_T, TOU_THRESH);
  set_register(0x5A, ELE4_R, REL_THRESH);
  
  set_register(0x5A, ELE5_T, TOU_THRESH);
  set_register(0x5A, ELE5_R, REL_THRESH);
  
  set_register(0x5A, ELE6_T, TOU_THRESH);
  set_register(0x5A, ELE6_R, REL_THRESH);
  
  set_register(0x5A, ELE7_T, TOU_THRESH);
  set_register(0x5A, ELE7_R, REL_THRESH);
  
  set_register(0x5A, ELE8_T, TOU_THRESH);
  set_register(0x5A, ELE8_R, REL_THRESH);
  
  set_register(0x5A, ELE9_T, TOU_THRESH);
  set_register(0x5A, ELE9_R, REL_THRESH);
  
  set_register(0x5A, ELE10_T, TOU_THRESH);
  set_register(0x5A, ELE10_R, REL_THRESH);
  
  set_register(0x5A, ELE11_T, TOU_THRESH);
  set_register(0x5A, ELE11_R, REL_THRESH);
  
  // Section D
  // Set the Filter Configuration
  // Set ESI2
  set_register(0x5A, FIL_CFG, 0x04);
  
  // Section E
  // Electrode Configuration
  // Set ELE_CFG to 0x00 to return to standby mode
  set_register(0x5A, ELE_CFG, 0x0C);  // Enables all 12 Electrodes
  
  
  // Section F
  // Enable Auto Config and auto Reconfig
  /*set_register(0x5A, ATO_CFG0, 0x0B);
  
  // USL = (Vdd-0.7)/vdd*256 = 0xC9 @3.3V   set_register(0x5A, ATO_CFGL, 0x82);  // LSL = 0.65*USL = 0x82 @3.3V
  set_register(0x5A, ATO_CFGU, 0xC9);  
  set_register(0x5A, ATO_CFGT, 0xB5);*/  // Target = 0.9*USL = 0xB5 @3.3V
  
  set_register(0x5A, ELE_CFG, 0x0C);
  
}


boolean checkInterrupt(void){
  return digitalRead(irqpin);
}


void set_register(int address, unsigned char r, unsigned char v){
    Wire.beginTransmission(address);
    Wire.write(r);
    Wire.write(v);
    Wire.endTransmission();
}


Optimerad för att passa knpparna och lysdioden

Bara kod för att fÄ knapparna och lysdioden att funka.
Har ocksÄ tagit bort alla 'serial.print' och sparat minnet.

Optimerad kod. Alternativ för fil: 'main.cpp'

#include <Arduino.h>
#include <Wire.h>
#include "mpr121.h"
//Optimerad kod.

void mpr121_setup(void);
void readTouchInputs();
void set_register(int address, unsigned char r, unsigned char v);
boolean checkInterrupt(void);

int irqpin = 2;  // Digital 2
int LEDpin = 9;  // Digital 9
boolean touchStates[12]; //to keep track of the previous touch states

void setup(){
  pinMode(irqpin, INPUT);
  digitalWrite(irqpin, HIGH); //enable pullup resistor
  
  pinMode(LEDpin, OUTPUT);
  digitalWrite(LEDpin, LOW);

  Wire.begin();

  mpr121_setup();
}

void loop(){
  readTouchInputs();
}

void readTouchInputs(){
  if(!checkInterrupt()){
    
    //read the touch state from the MPR121
    Wire.requestFrom(0x5A,2); 
    
    byte LSB = Wire.read();
    //Aktivera och anvĂ€nd MSB om du behöver lĂ€sa ingĂ„ngrna 8 till 11
    //byte MSB = Wire.read(); 

    if (LSB & B10000000){ //Kollar pinne 7
      digitalWrite(LEDpin, LOW);
    }
    
    if (LSB & B00100000){ //Kollar pinne 5
      digitalWrite(LEDpin, HIGH);
    }
  }
}

void mpr121_setup(void){

  set_register(0x5A, ELE_CFG, 0x00); 
  
  // Section A - Controls filtering when data is > baseline.
  set_register(0x5A, MHD_R, 0x01);
  set_register(0x5A, NHD_R, 0x01);
  set_register(0x5A, NCL_R, 0x00);
  set_register(0x5A, FDL_R, 0x00);

  // Section B - Controls filtering when data is < baseline.
  set_register(0x5A, MHD_F, 0x01);
  set_register(0x5A, NHD_F, 0x01);
  set_register(0x5A, NCL_F, 0xFF);
  set_register(0x5A, FDL_F, 0x02);
  
  // Section C - Sets touch and release thresholds for each electrode
  set_register(0x5A, ELE0_T, TOU_THRESH);
  set_register(0x5A, ELE0_R, REL_THRESH);
 
  set_register(0x5A, ELE1_T, TOU_THRESH);
  set_register(0x5A, ELE1_R, REL_THRESH);
  
  set_register(0x5A, ELE2_T, TOU_THRESH);
  set_register(0x5A, ELE2_R, REL_THRESH);
  
  set_register(0x5A, ELE3_T, TOU_THRESH);
  set_register(0x5A, ELE3_R, REL_THRESH);
  
  set_register(0x5A, ELE4_T, TOU_THRESH);
  set_register(0x5A, ELE4_R, REL_THRESH);
  
  set_register(0x5A, ELE5_T, TOU_THRESH);
  set_register(0x5A, ELE5_R, REL_THRESH);
  
  set_register(0x5A, ELE6_T, TOU_THRESH);
  set_register(0x5A, ELE6_R, REL_THRESH);
  
  set_register(0x5A, ELE7_T, TOU_THRESH);
  set_register(0x5A, ELE7_R, REL_THRESH);
  
  set_register(0x5A, ELE8_T, TOU_THRESH);
  set_register(0x5A, ELE8_R, REL_THRESH);
  
  set_register(0x5A, ELE9_T, TOU_THRESH);
  set_register(0x5A, ELE9_R, REL_THRESH);
  
  set_register(0x5A, ELE10_T, TOU_THRESH);
  set_register(0x5A, ELE10_R, REL_THRESH);
  
  set_register(0x5A, ELE11_T, TOU_THRESH);
  set_register(0x5A, ELE11_R, REL_THRESH);
  
  // Section D
  // Set the Filter Configuration
  // Set ESI2
  set_register(0x5A, FIL_CFG, 0x04);
  
  // Section E
  // Electrode Configuration
  // Set ELE_CFG to 0x00 to return to standby mode
  set_register(0x5A, ELE_CFG, 0x0C);  // Enables all 12 Electrodes
  
  
  // Section F
  // Enable Auto Config and auto Reconfig
  /*set_register(0x5A, ATO_CFG0, 0x0B);
  
  // USL = (Vdd-0.7)/vdd*256 = 0xC9 @3.3V   set_register(0x5A, ATO_CFGL, 0x82);  // LSL = 0.65*USL = 0x82 @3.3V
  set_register(0x5A, ATO_CFGU, 0xC9);  
  set_register(0x5A, ATO_CFGT, 0xB5);*/  // Target = 0.9*USL = 0xB5 @3.3V
  
  set_register(0x5A, ELE_CFG, 0x0C);
  
}


boolean checkInterrupt(void){
  return digitalRead(irqpin);
}


void set_register(int address, unsigned char r, unsigned char v){
    Wire.beginTransmission(address);
    Wire.write(r);
    Wire.write(v);
    Wire.endTransmission();
}


Kod med IRQ (interrupt request)(AvbrottsförfrÄgan)

Det gÄt inte att anvÀnda I2C i en Arduino IRQ.
Har jag fel?

Tack till alla som handlar pÄ PchButik.se.
Detta har gjort det möjligt att göra denna sida..
20250428 Per-Anders Hult för Pchbutik.se
ï»ż

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