mirror of
https://github.com/HASwitchPlate/openHASP.git
synced 2025-04-24 23:37:21 +00:00
53 lines
2.5 KiB
Markdown
53 lines
2.5 KiB
Markdown
# Adafruit TouchScreen with mod for ESP32 UNO
|
|
|
|
This is the 4-wire resistive touch screen firmware for Arduino. Works with all Arduinos and Teensy
|
|
|
|
|
|
To install, click DOWNLOAD SOURCE in the top right corner, and rename the uncompressed folder "TouchScreen". See our tutorial at http://www.ladyada.net/library/arduino/libraries.html on Arduino Library installation
|
|
|
|
Added modification to allow the 4-wire resistive touchscreen of MCU Friend LCDs with parallel data interfaces to be used with ESP32 UNO style boards whilst WiFi is enabled. Tested on a red board MCU Friend with default touchscreen wiring.
|
|
|
|
|
|
## Reason for Modification
|
|
|
|
ESP32 WiFi removes access to ADC2 channel so pins 4 and 15 attached to the touchscreen no longer have analog input capability. Pin 15 already shares a connection with analog pin 35, so an additional connection is made between pin 4 and analog pin 39. Pins 35 and 39 now provide the analog input. Pins 35 and 39 are input only so always present a high impedance to avoid the risk of two outputs shorting.
|
|
|
|
## Prerequisites
|
|
|
|
An extra wiring mod is needed in addition to those shown in the [TFT_eSPI](https://github.com/Bodmer/TFT_eSPI) instructions, but do not affect the software functionality or configuration.
|
|
|
|
Wiring for ESP UNO type board, with extra wire shown in green:
|
|
|
|
|
|
|
|
|
|
|
|
## Installing
|
|
|
|
Download and install the library using your IDE, eg Arduino.
|
|
The modification uses conditional compilation. To enable the changes, modify TouchScreen.h to uncomment #define ESP32_WIFI_TOUCH
|
|
|
|
```
|
|
// ESP32 specific
|
|
//#define ESP32_WIFI_TOUCH // uncomment to use parallel MCU Friend LCD touchscreen with ESP32 UNO Wifi
|
|
#ifdef ESP32
|
|
#define ADC_MAX 4095 // maximum value for ESP32 ADC (default 11db, 12 bits)
|
|
#define aXM 35 // analog input pin connected to LCD_RS
|
|
#define aYP 39 // analog input pin connected to LCD_WR
|
|
#else
|
|
#define ADC_MAX 1023 // Arduino
|
|
#endif
|
|
#define NOISE_LEVEL 4 // Allow small amount of measurement noise
|
|
```
|
|
|
|
|
|
## Using
|
|
|
|
No changes are required to existing sketches, just recompilation.
|
|
|
|
Compatible with both [TFT_eSPI](https://github.com/Bodmer/TFT_eSPI) and [MCUFRIEND_kbv](https://github.com/prenticedavid/MCUFRIEND_kbv/) libraries
|
|
|
|
Touchscreen needs to be calibrated before use, either manually using included [ESP32testTouch](examples/ESP32testTouch) or eg [TouchScreen_Calibr_native](https://github.com/prenticedavid/MCUFRIEND_kbv/tree/master/examples/TouchScreen_Calibr_native)
|
|
|
|
|