From dce34b37edd4ae6e823c797308fb83530f18242f Mon Sep 17 00:00:00 2001
From: ViezeVingertjes <michael.overhorst@gmail.com>
Date: Tue, 20 Jan 2026 16:03:04 +0100
Subject: [PATCH 1/2] Add M5Stack C6L variant with PI4IO GPIO expander support

---
 variants/m5stack_c6l/M5StackC6LBoard.cpp | 60 +++++++++++++++++++
 variants/m5stack_c6l/M5StackC6LBoard.h   | 38 ++++++++++++
 variants/m5stack_c6l/platformio.ini      | 76 ++++++++++++++++++++++++
 variants/m5stack_c6l/target.cpp          | 49 +++++++++++++++
 variants/m5stack_c6l/target.h            | 21 +++++++
 5 files changed, 244 insertions(+)
 create mode 100644 variants/m5stack_c6l/M5StackC6LBoard.cpp
 create mode 100644 variants/m5stack_c6l/M5StackC6LBoard.h
 create mode 100644 variants/m5stack_c6l/platformio.ini
 create mode 100644 variants/m5stack_c6l/target.cpp
 create mode 100644 variants/m5stack_c6l/target.h

diff --git a/variants/m5stack_c6l/M5StackC6LBoard.cpp b/variants/m5stack_c6l/M5StackC6LBoard.cpp
new file mode 100644
index 000000000..0bf527476
--- /dev/null
+++ b/variants/m5stack_c6l/M5StackC6LBoard.cpp
@@ -0,0 +1,60 @@
+#include "M5StackC6LBoard.h"
+
+void M5StackC6LBoard::pi4ioWriteByte(uint8_t reg, uint8_t value) {
+  Wire.beginTransmission(PI4IO_ADDR);
+  Wire.write(reg);
+  Wire.write(value);
+  Wire.endTransmission();
+}
+
+uint8_t M5StackC6LBoard::pi4ioReadByte(uint8_t reg) {
+  Wire.beginTransmission(PI4IO_ADDR);
+  Wire.write(reg);
+  Wire.endTransmission();
+  Wire.requestFrom(PI4IO_ADDR, (uint8_t)1);
+  return Wire.read();
+}
+
+void M5StackC6LBoard::initGpioExpander() {
+  pi4ioWriteByte(PI4IO_REG_CHIP_RESET, 0xFF);
+  delay(10);
+
+  pi4ioReadByte(PI4IO_REG_CHIP_RESET);
+  delay(10);
+
+  pi4ioWriteByte(PI4IO_REG_IO_DIR, 0b11000000);
+  delay(10);
+
+  pi4ioWriteByte(PI4IO_REG_OUT_H_IM, 0b00111100);
+  delay(10);
+
+  pi4ioWriteByte(PI4IO_REG_PULL_SEL, 0b11000011);
+  delay(10);
+
+  pi4ioWriteByte(PI4IO_REG_PULL_EN, 0b11000011);
+  delay(10);
+
+  pi4ioWriteByte(PI4IO_REG_IN_DEF_STA, 0b00000011);
+  delay(10);
+
+  pi4ioWriteByte(PI4IO_REG_INT_MASK, 0b11111100);
+  delay(10);
+
+  pi4ioWriteByte(PI4IO_REG_OUT_SET, 0b10000000);
+  delay(10);
+
+  pi4ioReadByte(PI4IO_REG_IRQ_STA);
+
+  uint8_t out_set = pi4ioReadByte(PI4IO_REG_OUT_SET);
+  out_set |= (1 << 6);
+  pi4ioWriteByte(PI4IO_REG_OUT_SET, out_set);
+}
+
+void M5StackC6LBoard::begin() {
+  ESP32Board::begin();
+  initGpioExpander();
+}
+
+const char* M5StackC6LBoard::getManufacturerName() const {
+  return "M5Stack C6L";
+}
diff --git a/variants/m5stack_c6l/M5StackC6LBoard.h b/variants/m5stack_c6l/M5StackC6LBoard.h
new file mode 100644
index 000000000..dc4f0cc40
--- /dev/null
+++ b/variants/m5stack_c6l/M5StackC6LBoard.h
@@ -0,0 +1,38 @@
+#pragma once
+
+#include <Arduino.h>
+#include <Wire.h>
+#include <helpers/ESP32Board.h>
+
+#define PI4IO_ADDR 0x43
+
+#define PI4IO_REG_CHIP_RESET 0x01
+#define PI4IO_REG_IO_DIR 0x03
+#define PI4IO_REG_OUT_SET 0x05
+#define PI4IO_REG_OUT_H_IM 0x07
+#define PI4IO_REG_IN_DEF_STA 0x09
+#define PI4IO_REG_PULL_EN 0x0B
+#define PI4IO_REG_PULL_SEL 0x0D
+#define PI4IO_REG_IN_STA 0x0F
+#define PI4IO_REG_INT_MASK 0x11
+#define PI4IO_REG_IRQ_STA 0x13
+
+class M5StackC6LBoard : public ESP32Board {
+public:
+  void begin();
+  const char* getManufacturerName() const override;
+
+#ifdef P_LORA_TX_NEOPIXEL
+  void onBeforeTransmit() override {
+    neopixelWrite(P_LORA_TX_NEOPIXEL, 64, 64, 64);
+  }
+  void onAfterTransmit() override {
+    neopixelWrite(P_LORA_TX_NEOPIXEL, 0, 0, 0);
+  }
+#endif
+
+private:
+  void pi4ioWriteByte(uint8_t reg, uint8_t value);
+  uint8_t pi4ioReadByte(uint8_t reg);
+  void initGpioExpander();
+};
diff --git a/variants/m5stack_c6l/platformio.ini b/variants/m5stack_c6l/platformio.ini
new file mode 100644
index 000000000..82e7e46ba
--- /dev/null
+++ b/variants/m5stack_c6l/platformio.ini
@@ -0,0 +1,76 @@
+[m5stack_c6l]
+extends = esp32c6_base
+board = esp32-c6-devkitc-1
+board_upload.flash_size = 16MB
+board_build.partitions = default_16MB.csv
+build_flags =
+  ${esp32c6_base.build_flags}
+  -I variants/m5stack_c6l
+  -D ARDUINO_USB_CDC_ON_BOOT=1
+  -D ARDUINO_USB_MODE=1
+  -D P_LORA_TX_NEOPIXEL=2
+  -D P_LORA_SCLK=20
+  -D P_LORA_MISO=22
+  -D P_LORA_MOSI=21
+  -D P_LORA_NSS=23
+  -D P_LORA_DIO_1=7
+  -D P_LORA_BUSY=19
+  -D P_LORA_RESET=RADIOLIB_NC
+  -D PIN_BOARD_SDA=10
+  -D PIN_BOARD_SCL=8
+  -D SX126X_DIO2_AS_RF_SWITCH=true
+  -D SX126X_DIO3_TCXO_VOLTAGE=3.0
+  -D SX126X_CURRENT_LIMIT=140
+  -D SX126X_RX_BOOSTED_GAIN=1
+  -D RADIO_CLASS=CustomSX1262
+  -D WRAPPER_CLASS=CustomSX1262Wrapper
+  -D LORA_TX_POWER=22
+  -D DISABLE_WIFI_OTA=1
+build_src_filter = ${esp32c6_base.build_src_filter}
+  +<../variants/m5stack_c6l>
+
+[env:m5stack_c6l_repeater]
+extends = m5stack_c6l
+build_src_filter = ${m5stack_c6l.build_src_filter}
+  +<../examples/simple_repeater/*.cpp>
+build_flags =
+  ${m5stack_c6l.build_flags}
+  -D ADVERT_NAME='"M5Stack C6L Repeater"'
+  -D ADVERT_LAT=0.0
+  -D ADVERT_LON=0.0
+  -D ADMIN_PASSWORD='"password"'
+  -D MAX_NEIGHBOURS=50
+lib_deps =
+  ${m5stack_c6l.lib_deps}
+
+[env:m5stack_c6l_room_server]
+extends = m5stack_c6l
+build_src_filter = ${m5stack_c6l.build_src_filter}
+  +<../examples/simple_room_server>
+build_flags =
+  ${m5stack_c6l.build_flags}
+  -D ADVERT_NAME='"M5Stack C6L Room"'
+  -D ADVERT_LAT=0.0
+  -D ADVERT_LON=0.0
+  -D ADMIN_PASSWORD='"password"'
+  -D ROOM_PASSWORD='"hello"'
+lib_deps =
+  ${m5stack_c6l.lib_deps}
+
+[env:m5stack_c6l_companion_radio_ble]
+extends = m5stack_c6l
+build_flags = ${m5stack_c6l.build_flags}
+  -D MAX_CONTACTS=350
+  -D MAX_GROUP_CHANNELS=40
+  -D BLE_PIN_CODE=123456
+  -D BLE_DEBUG_LOGGING=1
+  -D OFFLINE_QUEUE_SIZE=256
+  -D ENABLE_PRIVATE_KEY_IMPORT=1
+  -D ENABLE_PRIVATE_KEY_EXPORT=1
+build_src_filter = ${m5stack_c6l.build_src_filter}
+  +<helpers/esp32/*.cpp>
+  -<helpers/esp32/ESPNOWRadio.cpp>
+  +<../examples/companion_radio/*.cpp>
+lib_deps =
+  ${m5stack_c6l.lib_deps}
+  densaugeo/base64 @ ~1.4.0
diff --git a/variants/m5stack_c6l/target.cpp b/variants/m5stack_c6l/target.cpp
new file mode 100644
index 000000000..3a2912bd7
--- /dev/null
+++ b/variants/m5stack_c6l/target.cpp
@@ -0,0 +1,49 @@
+#include <Arduino.h>
+#include "target.h"
+
+M5StackC6LBoard board;
+
+#if defined(P_LORA_SCLK)
+  static SPIClass spi(0);
+  RADIO_CLASS radio = new Module(P_LORA_NSS, P_LORA_DIO_1, P_LORA_RESET, P_LORA_BUSY, spi);
+#else
+  RADIO_CLASS radio = new Module(P_LORA_NSS, P_LORA_DIO_1, P_LORA_RESET, P_LORA_BUSY);
+#endif
+
+WRAPPER_CLASS radio_driver(radio, board);
+
+ESP32RTCClock fallback_clock;
+AutoDiscoverRTCClock rtc_clock(fallback_clock);
+SensorManager sensors;
+
+bool radio_init() {
+  fallback_clock.begin();
+  rtc_clock.begin(Wire);
+
+#if defined(P_LORA_SCLK)
+  spi.begin(P_LORA_SCLK, P_LORA_MISO, P_LORA_MOSI);
+  return radio.std_init(&spi);
+#else
+  return radio.std_init();
+#endif
+}
+
+uint32_t radio_get_rng_seed() {
+  return radio.random(0x7FFFFFFF);
+}
+
+void radio_set_params(float freq, float bw, uint8_t sf, uint8_t cr) {
+  radio.setFrequency(freq);
+  radio.setSpreadingFactor(sf);
+  radio.setBandwidth(bw);
+  radio.setCodingRate(cr);
+}
+
+void radio_set_tx_power(uint8_t dbm) {
+  radio.setOutputPower(dbm);
+}
+
+mesh::LocalIdentity radio_new_identity() {
+  RadioNoiseListener rng(radio);
+  return mesh::LocalIdentity(&rng);
+}
diff --git a/variants/m5stack_c6l/target.h b/variants/m5stack_c6l/target.h
new file mode 100644
index 000000000..49baf2b58
--- /dev/null
+++ b/variants/m5stack_c6l/target.h
@@ -0,0 +1,21 @@
+#pragma once
+
+#define RADIOLIB_STATIC_ONLY 1
+#include <RadioLib.h>
+#include <M5StackC6LBoard.h>
+#include <helpers/radiolib/RadioLibWrappers.h>
+#include <helpers/ESP32Board.h>
+#include <helpers/radiolib/CustomSX1262Wrapper.h>
+#include <helpers/AutoDiscoverRTCClock.h>
+#include <helpers/SensorManager.h>
+
+extern M5StackC6LBoard board;
+extern WRAPPER_CLASS radio_driver;
+extern AutoDiscoverRTCClock rtc_clock;
+extern SensorManager sensors;
+
+bool radio_init();
+uint32_t radio_get_rng_seed();
+void radio_set_params(float freq, float bw, uint8_t sf, uint8_t cr);
+void radio_set_tx_power(uint8_t dbm);
+mesh::LocalIdentity radio_new_identity();

From e274ca91ee5c1e89a99241953329ba24aa6dd535 Mon Sep 17 00:00:00 2001
From: ViezeVingertjes <michael.overhorst@gmail.com>
Date: Tue, 20 Jan 2026 16:19:30 +0100
Subject: [PATCH 2/2] Add SPI SSD1306 display support for M5Stack C6L

---
 src/helpers/ui/SSD1306SpiDisplay.cpp | 71 ++++++++++++++++++++++++++++
 src/helpers/ui/SSD1306SpiDisplay.h   | 43 +++++++++++++++++
 variants/m5stack_c6l/platformio.ini  | 39 +++++++++++++++
 variants/m5stack_c6l/target.cpp      |  4 ++
 variants/m5stack_c6l/target.h        |  7 +++
 5 files changed, 164 insertions(+)
 create mode 100644 src/helpers/ui/SSD1306SpiDisplay.cpp
 create mode 100644 src/helpers/ui/SSD1306SpiDisplay.h

diff --git a/src/helpers/ui/SSD1306SpiDisplay.cpp b/src/helpers/ui/SSD1306SpiDisplay.cpp
new file mode 100644
index 000000000..6613751f4
--- /dev/null
+++ b/src/helpers/ui/SSD1306SpiDisplay.cpp
@@ -0,0 +1,71 @@
+#include "SSD1306SpiDisplay.h"
+
+bool SSD1306SpiDisplay::begin() {
+#ifdef DISPLAY_ROTATION
+  display.setRotation(DISPLAY_ROTATION);
+#endif
+  return display.begin(SSD1306_SWITCHCAPVCC);
+}
+
+void SSD1306SpiDisplay::turnOn() {
+  display.ssd1306_command(SSD1306_DISPLAYON);
+  _isOn = true;
+}
+
+void SSD1306SpiDisplay::turnOff() {
+  display.ssd1306_command(SSD1306_DISPLAYOFF);
+  _isOn = false;
+}
+
+void SSD1306SpiDisplay::clear() {
+  display.clearDisplay();
+  display.display();
+}
+
+void SSD1306SpiDisplay::startFrame(Color bkg) {
+  display.clearDisplay();
+  _color = SSD1306_WHITE;
+  display.setTextColor(_color);
+  display.setTextSize(1);
+  display.cp437(true);
+}
+
+void SSD1306SpiDisplay::setTextSize(int sz) {
+  display.setTextSize(sz);
+}
+
+void SSD1306SpiDisplay::setColor(Color c) {
+  _color = (c != 0) ? SSD1306_WHITE : SSD1306_BLACK;
+  display.setTextColor(_color);
+}
+
+void SSD1306SpiDisplay::setCursor(int x, int y) {
+  display.setCursor(x, y);
+}
+
+void SSD1306SpiDisplay::print(const char* str) {
+  display.print(str);
+}
+
+void SSD1306SpiDisplay::fillRect(int x, int y, int w, int h) {
+  display.fillRect(x, y, w, h, _color);
+}
+
+void SSD1306SpiDisplay::drawRect(int x, int y, int w, int h) {
+  display.drawRect(x, y, w, h, _color);
+}
+
+void SSD1306SpiDisplay::drawXbm(int x, int y, const uint8_t* bits, int w, int h) {
+  display.drawBitmap(x, y, bits, w, h, SSD1306_WHITE);
+}
+
+uint16_t SSD1306SpiDisplay::getTextWidth(const char* str) {
+  int16_t x1, y1;
+  uint16_t w, h;
+  display.getTextBounds(str, 0, 0, &x1, &y1, &w, &h);
+  return w;
+}
+
+void SSD1306SpiDisplay::endFrame() {
+  display.display();
+}
diff --git a/src/helpers/ui/SSD1306SpiDisplay.h b/src/helpers/ui/SSD1306SpiDisplay.h
new file mode 100644
index 000000000..1757a0070
--- /dev/null
+++ b/src/helpers/ui/SSD1306SpiDisplay.h
@@ -0,0 +1,43 @@
+#pragma once
+
+#include "DisplayDriver.h"
+#include <SPI.h>
+#include <Adafruit_GFX.h>
+#define SSD1306_NO_SPLASH
+#include <Adafruit_SSD1306.h>
+
+#ifndef SSD1306_SPI_WIDTH
+  #define SSD1306_SPI_WIDTH 64
+#endif
+
+#ifndef SSD1306_SPI_HEIGHT
+  #define SSD1306_SPI_HEIGHT 48
+#endif
+
+class SSD1306SpiDisplay : public DisplayDriver {
+  Adafruit_SSD1306 display;
+  bool _isOn;
+  uint8_t _color;
+
+public:
+  SSD1306SpiDisplay() : DisplayDriver(SSD1306_SPI_WIDTH, SSD1306_SPI_HEIGHT), 
+    display(SSD1306_SPI_WIDTH, SSD1306_SPI_HEIGHT, &SPI, PIN_SPI_DISPLAY_DC, PIN_SPI_DISPLAY_RST, PIN_SPI_DISPLAY_CS) { 
+    _isOn = false; 
+  }
+
+  bool begin();
+  bool isOn() override { return _isOn; }
+  void turnOn() override;
+  void turnOff() override;
+  void clear() override;
+  void startFrame(Color bkg = DARK) override;
+  void setTextSize(int sz) override;
+  void setColor(Color c) override;
+  void setCursor(int x, int y) override;
+  void print(const char* str) override;
+  void fillRect(int x, int y, int w, int h) override;
+  void drawRect(int x, int y, int w, int h) override;
+  void drawXbm(int x, int y, const uint8_t* bits, int w, int h) override;
+  uint16_t getTextWidth(const char* str) override;
+  void endFrame() override;
+};
diff --git a/variants/m5stack_c6l/platformio.ini b/variants/m5stack_c6l/platformio.ini
index 82e7e46ba..ed951bb72 100644
--- a/variants/m5stack_c6l/platformio.ini
+++ b/variants/m5stack_c6l/platformio.ini
@@ -18,6 +18,12 @@ build_flags =
   -D P_LORA_RESET=RADIOLIB_NC
   -D PIN_BOARD_SDA=10
   -D PIN_BOARD_SCL=8
+  -D PIN_SPI_DISPLAY_CS=6
+  -D PIN_SPI_DISPLAY_DC=18
+  -D PIN_SPI_DISPLAY_RST=15
+  -D SSD1306_SPI_WIDTH=64
+  -D SSD1306_SPI_HEIGHT=48
+  -D PIN_BUZZER=11
   -D SX126X_DIO2_AS_RF_SWITCH=true
   -D SX126X_DIO3_TCXO_VOLTAGE=3.0
   -D SX126X_CURRENT_LIMIT=140
@@ -32,9 +38,11 @@ build_src_filter = ${esp32c6_base.build_src_filter}
 [env:m5stack_c6l_repeater]
 extends = m5stack_c6l
 build_src_filter = ${m5stack_c6l.build_src_filter}
+  +<helpers/ui/SSD1306SpiDisplay.cpp>
   +<../examples/simple_repeater/*.cpp>
 build_flags =
   ${m5stack_c6l.build_flags}
+  -D DISPLAY_CLASS=SSD1306SpiDisplay
   -D ADVERT_NAME='"M5Stack C6L Repeater"'
   -D ADVERT_LAT=0.0
   -D ADVERT_LON=0.0
@@ -42,13 +50,16 @@ build_flags =
   -D MAX_NEIGHBOURS=50
 lib_deps =
   ${m5stack_c6l.lib_deps}
+  adafruit/Adafruit SSD1306 @ ^2.5.13
 
 [env:m5stack_c6l_room_server]
 extends = m5stack_c6l
 build_src_filter = ${m5stack_c6l.build_src_filter}
+  +<helpers/ui/SSD1306SpiDisplay.cpp>
   +<../examples/simple_room_server>
 build_flags =
   ${m5stack_c6l.build_flags}
+  -D DISPLAY_CLASS=SSD1306SpiDisplay
   -D ADVERT_NAME='"M5Stack C6L Room"'
   -D ADVERT_LAT=0.0
   -D ADVERT_LON=0.0
@@ -56,10 +67,32 @@ build_flags =
   -D ROOM_PASSWORD='"hello"'
 lib_deps =
   ${m5stack_c6l.lib_deps}
+  adafruit/Adafruit SSD1306 @ ^2.5.13
+
+[env:m5stack_c6l_companion_radio_usb]
+extends = m5stack_c6l
+build_flags = ${m5stack_c6l.build_flags}
+  -I examples/companion_radio/ui-new
+  -D DISPLAY_CLASS=SSD1306SpiDisplay
+  -D MAX_CONTACTS=350
+  -D MAX_GROUP_CHANNELS=40
+build_src_filter = ${m5stack_c6l.build_src_filter}
+  +<helpers/ui/SSD1306SpiDisplay.cpp>
+  +<helpers/ui/MomentaryButton.cpp>
+  +<helpers/ui/buzzer.cpp>
+  +<../examples/companion_radio/*.cpp>
+  +<../examples/companion_radio/ui-new/*.cpp>
+lib_deps =
+  ${m5stack_c6l.lib_deps}
+  densaugeo/base64 @ ~1.4.0
+  adafruit/Adafruit SSD1306 @ ^2.5.13
+  end2endzone/NonBlockingRTTTL@^1.3.0
 
 [env:m5stack_c6l_companion_radio_ble]
 extends = m5stack_c6l
 build_flags = ${m5stack_c6l.build_flags}
+  -I examples/companion_radio/ui-new
+  -D DISPLAY_CLASS=SSD1306SpiDisplay
   -D MAX_CONTACTS=350
   -D MAX_GROUP_CHANNELS=40
   -D BLE_PIN_CODE=123456
@@ -68,9 +101,15 @@ build_flags = ${m5stack_c6l.build_flags}
   -D ENABLE_PRIVATE_KEY_IMPORT=1
   -D ENABLE_PRIVATE_KEY_EXPORT=1
 build_src_filter = ${m5stack_c6l.build_src_filter}
+  +<helpers/ui/SSD1306SpiDisplay.cpp>
+  +<helpers/ui/MomentaryButton.cpp>
+  +<helpers/ui/buzzer.cpp>
   +<helpers/esp32/*.cpp>
   -<helpers/esp32/ESPNOWRadio.cpp>
   +<../examples/companion_radio/*.cpp>
+  +<../examples/companion_radio/ui-new/*.cpp>
 lib_deps =
   ${m5stack_c6l.lib_deps}
   densaugeo/base64 @ ~1.4.0
+  adafruit/Adafruit SSD1306 @ ^2.5.13
+  end2endzone/NonBlockingRTTTL@^1.3.0
diff --git a/variants/m5stack_c6l/target.cpp b/variants/m5stack_c6l/target.cpp
index 3a2912bd7..64c07bcbd 100644
--- a/variants/m5stack_c6l/target.cpp
+++ b/variants/m5stack_c6l/target.cpp
@@ -16,6 +16,10 @@ ESP32RTCClock fallback_clock;
 AutoDiscoverRTCClock rtc_clock(fallback_clock);
 SensorManager sensors;
 
+#ifdef DISPLAY_CLASS
+  DISPLAY_CLASS display;
+#endif
+
 bool radio_init() {
   fallback_clock.begin();
   rtc_clock.begin(Wire);
diff --git a/variants/m5stack_c6l/target.h b/variants/m5stack_c6l/target.h
index 49baf2b58..39c8cf55c 100644
--- a/variants/m5stack_c6l/target.h
+++ b/variants/m5stack_c6l/target.h
@@ -8,12 +8,19 @@
 #include <helpers/radiolib/CustomSX1262Wrapper.h>
 #include <helpers/AutoDiscoverRTCClock.h>
 #include <helpers/SensorManager.h>
+#ifdef DISPLAY_CLASS
+  #include <helpers/ui/SSD1306SpiDisplay.h>
+#endif
 
 extern M5StackC6LBoard board;
 extern WRAPPER_CLASS radio_driver;
 extern AutoDiscoverRTCClock rtc_clock;
 extern SensorManager sensors;
 
+#ifdef DISPLAY_CLASS
+  extern DISPLAY_CLASS display;
+#endif
+
 bool radio_init();
 uint32_t radio_get_rng_seed();
 void radio_set_params(float freq, float bw, uint8_t sf, uint8_t cr);