SPD2010-Touch-Arduino

A pure-Arduino driver for the Solomon Systech SPD2010 capacitive touch-panel IC used on the waveshare 1.46@ esp32 dev-board...tested on ESP32-S3 but portable to any MCU with Wire.
No ESP-IDF glue, no heavyweight framework, no drama – drop the two files into your project and go.

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Why this repo exists

The Waveshare "ESP32-S3 1.46inch Round Display Development Board" ships with an ESP-IDF/Arduino wrapper that drags in a whole mass of extra components files that are all limmited/demo drivers and still refuses to compile on stock PlatformIO.
I spent three days reverse-engineering the protocol (and reading MicroPython sources) so you don’t have to.

https://www.waveshare.com/product/arduino/boards-kits/esp32-s3/esp32-s3-touch-lcd-1.46b.htm

Features

✔	Capability
Single-file SPD2010Touch.cpp / .h drop-in
Multi-touch (≤5 points × weight)
Swipe / scroll gesture byte
IRQ-driven, non-blocking polling (no delay() loops)
Optional reset via Adafruit XCA9554 I/O expander
Works at 400 kHz I²C on ESP32-S3, should down-clock happily to 100 kHz
Compile-time SPD_DEBUG switch – zero overhead when off

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Wiring

SPD2010 pin	MCU (ESP32-S3)	Notes
SDA	GPIO 11	Pull-ups already on Waveshare PCB
SCL	GPIO 10	400 kHz OK
INT	GPIO 4	Active-low, attachInterrupt FALLING
RST	optional via XCA9554 pin 0	Tie to expander if free GPIOs are scarce

I²C address is fixed at 0x53.

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Quick start

#include <Wire.h>
#include <Adafruit_XCA9554.h>
#include "SPD2010Touch.h"

constexpr uint8_t INT_PIN   = 4;
constexpr uint8_t RST_EXPin = 0;          // pin-0 on the XCA9554
constexpr uint8_t XCA_ADDR  = 0x20;       // A0..A2 = GND

Adafruit_XCA9554 expander;
SPD2010Touch     touch(Wire, RST_EXPin, INT_PIN, &expander);

void setup()
{
  Serial.begin(115200);
  Wire.begin(11 /*SDA*/, 10 /*SCL*/, 400000);

  expander.begin(XCA_ADDR);               // reset line lives here
  touch.begin();                          // prints FW version

  Serial.println("touch driver ready");
}

void loop()
{
  static uint32_t last;
  if (millis() - last < 10) return;       // 100 Hz poll
  last = millis();

  uint16_t x, y; uint8_t w;
  if (touch.getTouch(x, y, w))
    Serial.printf("x=%3u  y=%3u  weight=%u\n", x, y, w);
}

API

Method Description bool begin() initialise I²C, reset line, read FW bool available() true if an IRQ is pending bool read(TouchData &d) fill full struct (multi-touch) bool getTouch(uint16_t &x, uint16_t &y, uint8_t &w) single-finger helper uint8_t getTouchPoints(TouchPoint *buf, uint8_t max) array helper bool isTouched() any finger on glass uint8_t getGesture() swipe / scroll code void setInterruptCallback(cb) attach your own ISR if desired

See SPD2010Touch.h for the TouchData / TouchPoint layout.

Building

PlatformIO ini Copy Edit [env:esp32-s3] platform = espressif32 board = esp32-s3-devkitm-1 framework = arduino monitor_speed = 115200 build_flags = -DSPD_DEBUG=0 ; set =1 for verbose prints Just copy SPD2010Touch.cpp/.h into /src.

Arduino IDE 2.x Sketch ➜ Add File… ✓

Tools ➜ Core = ESP32 (3.0+ recommended)

Credits

Waveshare example (ESP-IDF) for the original register set

Kevin Schlosser for the MicroPython driver that confirmed the controller state-machine https://github.com/lvgl-micropython/lvgl_micropython/blob/main/api_drivers/common_api_drivers/indev/spd2010t.py

ChatGPT o3 for rubber-ducking through way too many crahses and failed calls.