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improved debounce by adding hysteresis
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@barry-ha
barry-ha committed Dec 13, 2023
1 parent 2b93de6 commit e66f734
Showing 1 changed file with 51 additions and 38 deletions.
89 changes: 51 additions & 38 deletions examples/Volume_Control/Volume_Control.ino
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Original file line number Diff line number Diff line change
Expand Up @@ -2,7 +2,8 @@
/*
Example Touchscreen UI for volume control buttons
Date: 2019-12-26 created
Date: 2023-12-12 improved debounce by adding hysteresis
2019-12-26 created
2019-12-26 moved pin X+ from D6 to A3 to match John's schematic
2020-05-12 updated TouchScreen code
Expand All @@ -18,13 +19,21 @@
there are 9 steps: 0, 1, 2, 4, 8, 16, 32, 64, 99
(I am not at all sure these are correct for 3 dB changes.)
+------------------------+
| +------+ |
| Volume | Up | |
| +------+ |
| Setting: 5 | Down | |
| +------+ |
+------------------------+
No speaker is needed - this demo does not produce sound.
+---------------------------------------+
| +---------------+ |
| Volume | Up | |
| Current | | |
| Value = 15 | | |
| | | |
| +---------------+ |
| | Down | |
| | | |
| | | |
| | | |
| +---------------+ |
+---------------------------------------+
You can expect calibration is needed for your touchscreen.
(a) measure resistance across X plate with ohmmeter, and
Expand All @@ -42,16 +51,17 @@
*/

#include <Adafruit_ILI9341.h> // TFT color display library
#include "TouchScreen.h" // Touchscreen built in to 3.2" Adafruit TFT display
#include <TouchScreen.h> // Touchscreen built in to 3.2" Adafruit TFT display

// ------- TFT 4-Wire Resistive Touch Screen configuration parameters
#define TOUCHPRESSURE 200 // Minimum pressure threshhold considered an actual "press"
#define XP_XM_OHMS 295 // Resistance in ohms between X+ and X- to calibrate pressure
// measure this with an ohmmeter while Griduino turned off
#define START_TOUCH_PRESSURE 200 // Minimum pressure threshold considered start of "press"
#define END_TOUCH_PRESSURE 50 // Maximum pressure threshold required before end of "press"
#define XP_XM_OHMS 295 // Resistance in ohms between X+ and X- to calibrate pressure
// measure this with an ohmmeter while Griduino turned off

// ------- Identity for splash screen and console --------
#define PROGRAM_TITLE "Volume Control Demo"
#define PROGRAM_VERSION "v1.12"
#define PROGRAM_VERSION "v1.13"
#define PROGRAM_LINE1 "Barry K7BWH"
#define PROGRAM_LINE2 "John KM7O"
#define PROGRAM_COMPILED __DATE__ " " __TIME__
Expand Down Expand Up @@ -83,11 +93,9 @@ TFT No connection:

// TFT display and SD card share the hardware SPI interface, and have
// separate 'select' pins to identify the active device on the bus.
#if defined(ARDUINO_AVR_MEGA2560)
#define TFT_DC 9 // TFT display/command pin
#define TFT_CS 10 // TFT select pin

#elif defined(SAMD_SERIES)
#if defined(SAMD_SERIES)
#warning----- Compiling for Arduino Feather M4 Express -----
// Adafruit Feather M4 Express pin definitions
// To compile for Feather M0/M4, install "additional boards manager"
// https://learn.adafruit.com/adafruit-feather-m4-express-atsamd51/setup
Expand All @@ -98,10 +106,10 @@ TFT No connection:

#else
#warning You need to define pins for your hardware

#error Hardware platform unknown.
#endif

// create an instance of the TFT Display
// ---------- TFT display
Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC);

// ---------- Touch Screen
Expand Down Expand Up @@ -154,9 +162,9 @@ const int gRotation = 1; // This rotates the display coordinate system

const int gNumButtons = 2;
Rectangle gaRect[gNumButtons] = {
// x, y, width, height, label
{160, 0, 160, 120, "Up"},
{160, 120, 160, 120, "Down"},
// x, y, w, ht, label
{160, 4, 156, 115, "Louder"},
{160, 120, 156, 115, "Softer"},
};

// ------------ global scope
Expand Down Expand Up @@ -243,7 +251,7 @@ bool newScreenTap(Point *pPoint) {
} else {
// here, we know the screen was not being touched in the last pass,
// so look for a new touch on this pass
// The built-in "isTouching" function does most of the debounce and threshhold detection needed
// Our replacement "isTouching" function does some of the debounce and threshold detection needed
if (ts.isTouching()) {
gTouching = true;
result = true;
Expand All @@ -270,14 +278,14 @@ bool newScreenTap(Point *pPoint) {
// 2020-05-03 CraigV and barry@k7bwh.com
uint16_t myPressure(void) {
pinMode(PIN_XP, OUTPUT);
digitalWrite(PIN_XP, LOW); // Set X+ to ground
pinMode(PIN_YM, OUTPUT);
digitalWrite(PIN_XP, LOW); // Set X+ to ground
pinMode(PIN_YM, OUTPUT); //
digitalWrite(PIN_YM, HIGH); // Set Y- to VCC

digitalWrite(PIN_XM, LOW);
pinMode(PIN_XM, INPUT); // Hi-Z X-
digitalWrite(PIN_YP, LOW);
pinMode(PIN_YP, INPUT); // Hi-Z Y+
pinMode(PIN_XM, INPUT); // Set X- to Hi-Z
digitalWrite(PIN_YP, LOW); //
pinMode(PIN_YP, INPUT); // Set Y+ to Hi-Z

int z1 = analogRead(PIN_XM);
int z2 = 1023 - analogRead(PIN_YP);
Expand All @@ -292,13 +300,13 @@ bool TouchScreen::isTouching(void) {
static bool button_state = false;
uint16_t pres_val = ::myPressure();

if ((button_state == false) && (pres_val > TOUCHPRESSURE)) {
if ((button_state == false) && (pres_val > START_TOUCH_PRESSURE)) {
Serial.print(". pressed, pressure = ");
Serial.println(pres_val); // debug
button_state = true;
}

if ((button_state == true) && (pres_val < TOUCHPRESSURE)) {
if ((button_state == true) && (pres_val < END_TOUCH_PRESSURE)) {
Serial.print(". released, pressure = ");
Serial.println(pres_val); // debug
button_state = false;
Expand Down Expand Up @@ -365,7 +373,7 @@ void showActivityBar(int row, uint16_t foreground, uint16_t background) {
static int addDotX = 10; // current screen column, 0..319 pixels
static int rmvDotX = 0;
static int count = 0;
const int SCALEF = 2048; // how much to slow it down so it becomes visible
const int SCALEF = 64; // how much to slow it down so it becomes visible

count = (count + 1) % SCALEF;
if (count == 0) {
Expand All @@ -380,11 +388,11 @@ void showActivityBar(int row, uint16_t foreground, uint16_t background) {
void setup() {

// ----- init TFT display
tft.begin(); // initialize TFT display
tft.setRotation(gRotation); // 1=landscape (default is 0=portrait)
clearScreen(); // note that "begin()" does not clear screen
tft.begin(); // initialize TFT display
tft.setRotation(gRotation); // 1=landscape (default is 0=portrait)
tft.fillScreen(cBACKGROUND); // note that "begin()" does not clear screen

// ----- init serial monitor
// ----- init serial monitor (do not "Serial.print" before this, it won't show up in console)
Serial.begin(115200); // init for debugging in the Arduino IDE
waitForSerial(howLongToWait); // wait for developer to connect debugging console

Expand All @@ -399,6 +407,11 @@ void setup() {
tft.setCursor(8, 24);
tft.print("Volume");

tft.setTextSize(1);
tft.setTextColor(cTEXTCOLOR, cBACKGROUND);
tft.setCursor(6, tft.height() - 16);
tft.print(PROGRAM_TITLE " " PROGRAM_VERSION);

showVolumeSetting(gVolume);

drawButtons();
Expand All @@ -424,7 +437,7 @@ void loop() {
break;
}
}
// make a small progress bar crawl along bottom edge
// this gives a sense of how frequently the main loop is executing
// showActivityBar(239, ILI9341_RED, ILI9341_BLACK);
// small activity bar crawls along bottom edge to give
// a sense of how frequently the main loop is executing
showActivityBar(tft.height() - 1, ILI9341_RED, ILI9341_BLACK);
}

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