GxEPD2-esphome/tools/gxepd2_harness/run_harness.h

#pragma once

// Drives one vendor GxEPD2 driver through the same low-level calls the
// GxEPD2_BW/GxEPD2_3C wrapper templates make for a single non-paged full
// update (writeImage() then refresh()) - bypassing the wrapper templates
// themselves (and their Adafruit_GFX dependency) since we only need the
// driver-level trace, not drawing helpers. After the full update it also
// runs the window-encoder sweep (window_sweep.h) - adopted as the standard
// capture step for every panel, to derive and cross-check the coordinate ->
// window-byte math by observation rather than by hand.

#include <cstdio>
#include <cstring>

#include "spy/Arduino.h"
#include "spy/SPI.h"
#include "trace.h"
#include "window_sweep.h"

// Exposes GxEPD2_EPD's protected busy_level/reset_duration without needing
// to parse anything - a subclass can read its own base class's protected
// members directly.
template<typename Driver> struct Peek : Driver {
  using Driver::Driver;
  int busy_level() const { return this->_busy_level; }
  uint16_t reset_duration() const { return this->_reset_duration; }
};

// planes=1 for monochrome drivers (color buffer still passed - harmless,
// see e.g. GxEPD2_290_T94::writeImage(black,color,...) which just ignores
// a non-null color pointer's absence).
template<typename Driver> void run_harness(const char *name) {
  printf("=== %s: WIDTH=%u HEIGHT=%u ===\n", name, (unsigned) Driver::WIDTH, (unsigned) Driver::HEIGHT);

  constexpr int16_t CS = 10, DC = 11, RST = 12, BUSY = 13;
  Trace::set_dc_pin(DC);

  Peek<Driver> driver(CS, DC, RST, BUSY);
  printf("busy_level=%d reset_duration=%u\n", driver.busy_level(), driver.reset_duration());
  // digitalRead(BUSY) should report "released" immediately - opposite of
  // busy_level - so _waitWhileBusy()'s loop exits after one check.
  Trace::last_busy_release_value = driver.busy_level() == HIGH ? LOW : HIGH;

  driver.selectSPI(SPI, SPISettings());

  printf("--- init(0) ---\n");
  driver.init(0);

  const uint32_t plane_bytes = (static_cast<uint32_t>(Driver::WIDTH) * Driver::HEIGHT) / 8;
  auto *black = new uint8_t[plane_bytes];
  auto *color = new uint8_t[plane_bytes];
  // Distinctive, non-0x00/0xFF pattern - lets a plane's invert flag be
  // read directly off the trace (does the wire byte equal 0xA5 or 0x5A).
  memset(black, 0xA5, plane_bytes);
  memset(color, 0xA5, plane_bytes);

  printf("--- writeImage(black, color, 0, 0, WIDTH, HEIGHT) ---\n");
  driver.writeImage(black, color, 0, 0, Driver::WIDTH, Driver::HEIGHT);

  printf("--- refresh(false) ---\n");
  driver.refresh(false);

  // Standard window-encoder sweep for every panel (runs after the initial
  // full refresh above, which satisfies run_window_sweep's precondition).
  run_window_sweep(driver, Driver::WIDTH, Driver::HEIGHT);

  delete[] black;
  delete[] color;
}