From 2517b1d7690e5c406d9e647cd5d565624efede8a Mon Sep 17 00:00:00 2001
From: Todd Herbert <herbert.todd@gmail.com>
Date: Mon, 24 Mar 2025 22:24:23 +1300
Subject: [PATCH] feat: driver for display HINK_E042A87 As of Feb. 2025, these
 panels are used for "WeActStudio 4.2in B&W" display modules.

---
 .../niche/Drivers/EInk/HINK_E042A87.cpp       | 58 +++++++++++++++++++
 .../niche/Drivers/EInk/HINK_E042A87.h         | 43 ++++++++++++++
 2 files changed, 101 insertions(+)
 create mode 100644 src/graphics/niche/Drivers/EInk/HINK_E042A87.cpp
 create mode 100644 src/graphics/niche/Drivers/EInk/HINK_E042A87.h

diff --git a/src/graphics/niche/Drivers/EInk/HINK_E042A87.cpp b/src/graphics/niche/Drivers/EInk/HINK_E042A87.cpp
new file mode 100644
index 000000000..1b72bc4a9
--- /dev/null
+++ b/src/graphics/niche/Drivers/EInk/HINK_E042A87.cpp
@@ -0,0 +1,58 @@
+#include "./HINK_E042A87.h"
+
+#ifdef MESHTASTIC_INCLUDE_NICHE_GRAPHICS
+
+using namespace NicheGraphics::Drivers;
+
+// Load settings about how the pixels are moved from old state to new state during a refresh
+// - manually specified,
+// - or with stored values from displays OTP memory
+void HINK_E042A87::configWaveform()
+{
+    sendCommand(0x3C); // Border waveform:
+    sendData(0x01);    // Follow LUT for VSH1
+
+    sendCommand(0x18); // Temperature sensor:
+    sendData(0x80);    // Use internal temperature sensor to select an appropriate refresh waveform
+}
+
+// Describes the sequence of events performed by the displays controller IC during a refresh
+// Includes "power up", "load settings from memory", "update the pixels", etc
+void HINK_E042A87::configUpdateSequence()
+{
+    switch (updateType) {
+    case FAST:
+        sendCommand(0x21); // Use both "old" and "new" image memory (differential)
+        sendData(0x00);
+        sendData(0x00);
+
+        sendCommand(0x22); // Set "update sequence"
+        sendData(0xFF);    // Differential, load waveform from OTP
+        break;
+
+    case FULL:
+    default:
+        sendCommand(0x21); // Bypass "old" image memory (non-differential)
+        sendData(0x40);
+        sendData(0x00);
+
+        sendCommand(0x22); // Set "update sequence":
+        sendData(0xF7);    // Non-differential, load waveform from OTP
+        break;
+    }
+}
+
+// Once the refresh operation has been started,
+// begin periodically polling the display to check for completion, using the normal Meshtastic threading code
+// Only used when refresh is "async"
+void HINK_E042A87::detachFromUpdate()
+{
+    switch (updateType) {
+    case FAST:
+        return beginPolling(50, 1000); // At least 1 second, then check every 50ms
+    case FULL:
+    default:
+        return beginPolling(100, 3500); // At least 3.5 seconds, then check every 100ms
+    }
+}
+#endif // MESHTASTIC_INCLUDE_NICHE_GRAPHICS
\ No newline at end of file
diff --git a/src/graphics/niche/Drivers/EInk/HINK_E042A87.h b/src/graphics/niche/Drivers/EInk/HINK_E042A87.h
new file mode 100644
index 000000000..ac03b65ef
--- /dev/null
+++ b/src/graphics/niche/Drivers/EInk/HINK_E042A87.h
@@ -0,0 +1,43 @@
+/*
+
+E-Ink display driver
+    - HINK-E042A87
+    - Manufacturer: Holitech
+    - Size: 4.2 inch
+    - Resolution: 400px x 300px
+    - Flex connector marking: HINK-E042A07-FPC-A1
+    - Silver sticker with QR code, marked: HE042A87
+
+    Note: as of Feb. 2025, these panels are used for "WeActStudio 4.2in B&W" display modules
+
+*/
+
+#pragma once
+
+#ifdef MESHTASTIC_INCLUDE_NICHE_GRAPHICS
+
+#include "configuration.h"
+
+#include "./SSD16XX.h"
+
+namespace NicheGraphics::Drivers
+{
+class HINK_E042A87 : public SSD16XX
+{
+    // Display properties
+  private:
+    static constexpr uint32_t width = 400;
+    static constexpr uint32_t height = 300;
+    static constexpr UpdateTypes supported = (UpdateTypes)(FULL | FAST);
+
+  public:
+    HINK_E042A87() : SSD16XX(width, height, supported) {}
+
+  protected:
+    void configWaveform() override;
+    void configUpdateSequence() override;
+    void detachFromUpdate() override;
+};
+
+} // namespace NicheGraphics::Drivers
+#endif // MESHTASTIC_INCLUDE_NICHE_GRAPHICS
\ No newline at end of file