ADKey_Board_10Keys_SKU_DFR0792-DFRobot

Introduction

This ADKey board with 10 keys can be used to drive your DFPlayer Pro, DFPlayer Mini, or Voice Recorder Module without programming or using various resistors. It offers 20 delicate key caps with comfortable hand feel, easy to be integrated in projects. You can also connect your favorite keys to the board through the welding pad on both sides. In addition, this ADkey board can be used as the ADkey input of a main-controller, by which it could expand 10 keys for your main-board via only one analog port.

Application

• Drive DFPlayer PRO
• Drive DFPlayer Mini
• Drive Voice Recorder Module
• Main-controller Button Expansion

Specification

• Power Supply: 3.3~5V
• Key Size: 6×6×7mm
• Product Size: 40×40mm/1.57×1.57”

Board Overview

Schematics

Tutorial

NOTE: When using this board to drive modules like DFPlayer Pro, DFPlayer Mini or Voice Recorder module, please do not connect VCC to the board since these modules have been pulled up 22K internally.

Requirements

• Hardware
  • DFRduino UNO R3 (or similar) x 1
  • ADKey board x1
  • Jumper wires

• Software
  • Arduino IDE

Connection Diagram

Sample Code 1-Read Data

Press down a key, serial print a value.

#define ADPIN A0      //Read Pin

void setup() {
  Serial.begin(115200);
}

void loop() {
  // read the value from the sensor:
  Serial.println(analogRead(ADPIN));
  delay(10);
}

Expected Results

Sample Code 2-Read Key Value

Press a key on the board, serial print the corresponding key value.

#define RESOLUTION 10   //ADC resoltuion
#define MAXVALUE pow(2,RESOLUTION)  //Resolution corresponding value 
#define PRECISION 10   //Admissible error 
#define ADPIN A0      //Read pin 

uint32_t ADKeyVal[10] = {0};   //Corresponding key value 
uint32_t ADCKeyIn = 0;


void setup() {
  Serial.begin(115200);
  ADKeybegin();
}

void loop() {
  ADCKeyIn = analogRead(ADPIN);
  if(ADCKeyIn < (MAXVALUE-PRECISION)){
    Serial.print("K = ");
    Serial.println(getKey());
  }
  delay(10);
}


void ADKeybegin(){
  float RESValue[10] = {0, 3, 6.2, 9.1, 15, 24, 33, 51, 100, 220};  //Resistor resistance 
  for(uint8_t i = 0; i < 10; i++){
    ADKeyVal[i] = RESValue[i]/(RESValue[i]+22)*MAXVALUE;
  }
}

int8_t getKey(){
  for(uint8_t i = 0; i < 10;i++){
    if(ADCKeyIn > ADKeyVal[i]){
      if((ADCKeyIn - ADKeyVal[i]) < PRECISION){
        return i;
      }
    } else{
      if((ADKeyVal[i] - ADCKeyIn) < PRECISION){
        return i;
      }
    }
  }
  return -1;
}

Expected Results

Connection with DFPlayer Pro

Connection with DFPlayer Mini

Left:

Right:

Connection with Voice Recorder Module

FAQ

For any questions, advice or cool ideas to share, please visit the DFRobot Forum.

More Documents

• Schematics Diagram
• Dimension Diagram
• SVG