Supported LCD Displays

All displays use segment LCD technology controlled by I2C or 3-wire serial protocol. Select by controller type and application.

‍Development status: Versions 0.0.x are alpha/prerelease builds. API and behavior may change at any time, including breaking changes without semantic-versioning major bumps.

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LCD Build Macros

All LCD model implementations are enabled by default. To build only selected LCD models, define SEGLCD_DISABLE_ALL_LCDS and then enable each required model with its concrete macro:

LCD class	Enable macro
SegLCD_HT1621_4SegDegree	SEGLCD_ENABLE_HT1621_4SEGDEGREE
SegLCD_HT1621_6SegBat	SEGLCD_ENABLE_HT1621_6SEGBAT
SegLCD_HT1621_LCM0844	SEGLCD_ENABLE_HT1621_LCM0844
SegLCD_HT1621_LCM59011	SEGLCD_ENABLE_HT1621_LCM59011
SegLCD_HT1621_LCM88128	SEGLCD_ENABLE_HT1621_LCM88128
SegLCD_HT1621_Raw	SEGLCD_ENABLE_HT1621_RAW
SegLCD_HT1622_10Dig16Seg	SEGLCD_ENABLE_HT1622_10DIG16SEG
SegLCD_HT1622_Raw	SEGLCD_ENABLE_HT1622_RAW
SegLCD_PCF85134_Raw	SEGLCD_ENABLE_PCF85134_RAW
SegLCD_PCF85134_XygaxSegI2C	SEGLCD_ENABLE_PCF85134_XYGAX_SEG_I2C
SegLCD_PCF85176_2Row4DigSigBatPwr	SEGLCD_ENABLE_PCF85176_2ROW4DIGSIGBATPWR
SegLCD_PCF85176_4DR821B	SEGLCD_ENABLE_PCF85176_4DR821B
SegLCD_PCF85176_6DigitSignalBatteryProgress	SEGLCD_ENABLE_PCF85176_6DIGSIGBATTPROGRESS
SegLCD_PCF85176_OneDigit	SEGLCD_ENABLE_PCF85176_ONEDIGIT
SegLCD_PCF85176_Raw	SEGLCD_ENABLE_PCF85176_RAW
SegLCD_PCF85176_T1T2Lcd	SEGLCD_ENABLE_PCF85176_T1T2LCD
SegLCD_PCF85176_TempHumidity	SEGLCD_ENABLE_PCF85176_TEMPHUM
SegLCD_PCF8576_4Seg6SegMaintSegBatUnits	SEGLCD_ENABLE_PCF8576_4SEG6SEGMAINTSEGBATUNITS
SegLCD_VK0192_5DigSigBattProgress	SEGLCD_ENABLE_VK0192_5DIGSIGBATTPROGRESS
SegLCD_VK0192_Raw	SEGLCD_ENABLE_VK0192_RAW

Example:

-DSEGLCD_DISABLE_ALL_LCDS
-DSEGLCD_ENABLE_PCF85134_XYGAX_SEG_I2C

---

PCF85134 (I2C) Displays

Xygax SEG_I2C

Specifications:

• Digits: Up to 6 positions, depending on LCD glass population
• Features: Static segment layout, decimal handling through inline print() notation
• Wiring: I2C (SDA, SCL)
• I2C Address: 0x38 (SA0=0) or 0x39 (SA0=1)
• Controller: PCF85134
• Board Marking: SEG_I2C_V1.01 / SEG_I2C_V1.02
• Image:
• Example: examples/PCF85134/XygaxSegI2C/
• Purchase: https://github.com/xygax

Notes:

• Board version does not currently affect the library mapping.
• Known glass variants include 6-position and 4-position populations. The driver keeps a 6-byte RAM map for the largest known wiring.
• Some 4-position glass sketches show a down-arrow where the last decimal point would normally be. This is not implemented until RAM mapping is verified on hardware.

Code Example:

#include "SegTransportArduino.h"
#include "SegLCD_PCF85134_XygaxSegI2C.h"
#include <Wire.h>
 
SegTransportI2CArduino transport(Wire);
SegLCD_PCF85134_XygaxSegI2C lcd(transport);
 
lcd.init();
lcd.print("123.4");

---

PCF85176 (I2C) Displays

RAW LCD

Purpose: Testing and debugging new LCD implementations

• Type: Test harness
• Wiring: I2C only (2 pins: SDA, SCL)
• Features: Send raw segment data directly to controller
• Use Case: Prototype new displays before creating dedicated driver
• Example: examples/PCF85176/RawLCD/

---

6-Digit Signal/Battery/Progress

Specifications:

• Digits: 6 7-segment digits
• Features: Signal strength (4 bars), Battery level (3 states), Progress indicator
• Wiring: I2C (SDA, SCL)
• I2C Address: 0x38 (SA0=0) or 0x39 (SA0=1)
• Controller: PCF85176
• Image:
• Example: examples/PCF85176/6DigSigBattProgress/
• Purchase: https://www.aliexpress.com/item/1005008425148644.html

Code Example:

#include "SegTransportArduino.h"
#include "SegLCD_PCF85176_6DigSigBattProgress.h"
#include <Wire.h>
 
SegTransportI2CArduino transport(Wire);
SegLCD_PCF85176_6DigitSignalBatteryProgress lcd(transport);
 
lcd.init();
lcd.setCursor(0, 0);
lcd.print(123456);
lcd.setSignalLevel(3);   // 3 of 4 bars
lcd.setBatteryLevel(2);  // Medium battery

---

2-Row 4-Digit Signal/Battery/Power

Specifications:

• Digits: 2 rows × 4 digits
• Features: Signal (1 bit), Battery (4 levels), Power icon
• Wiring: I2C (SDA, SCL)
• I2C Address: 0x38 (SA0=0) or 0x39 (SA0=1)
• Controller: PCF85176
• Image:
• Example: examples/PCF85176/2Row4DigSigBatPwr/

Code Example:

#include "SegTransportArduino.h"
#include "SegLCD_PCF85176_2Row4DigSigBatPwr.h"
#include <Wire.h>
 
SegTransportI2CArduino transport(Wire);
SegLCD_PCF85176_2Row4DigSigBatPwr lcd(transport);
 
lcd.init();
lcd.setCursor(0, 0);
lcd.print(1234);
lcd.setCursor(1, 0);
lcd.print(5678);
lcd.setSignalLevel(1);
lcd.setBatteryLevel(4);
lcd.setPowerSymbol(true);

---

One Digit (Up to 5 Segments)

Specifications:

• Digits: 1 custom segment display
• Features: Customizable segment layout (up to 5 segments)
• Wiring: I2C (SDA, SCL)
• I2C Address: 0x38 (SA0=0) or 0x39 (SA0=1)
• Controller: PCF85176
• Image:
• Example: examples/PCF85176/OneDigit/
• Purchase: https://aliexpress.com/item/1005005410565386.html

---

Temperature/Humidity

Specifications:

• Digits: 6 7-segment digits
• Features: Temperature and humidity symbols
• Wiring: I2C (SDA, SCL)
• I2C Address: 0x38 (SA0=0) or 0x39 (SA0=1)
• Controller: PCF85176
• Image:
• Example: examples/PCF85176/TempHumidity/
• Purchase: https://aliexpress.com/item/1005003044283980.html

Code Example:

#include "SegTransportArduino.h"
#include "SegLCD_PCF85176_TempHum.h"
#include <Wire.h>
 
SegTransportI2CArduino transport(Wire);
SegLCD_PCF85176_TempHumidity lcd(transport);
 
lcd.init();
lcd.setCursor(0, 0);  // Temperature row
lcd.print(23);        // 23°C
lcd.setCursor(1, 0);  // Humidity row
lcd.print(45);        // 45%

---

T1T2 LCD

Specifications:

• Layout: 3-row display (Clock, T1 Label, T2 Label)
• Features: Multi-zone control for temperature sensors
• Wiring: I2C (SDA, SCL)
• I2C Address: 0x38 (SA0=0) or 0x39 (SA0=1)
• Controller: PCF85176
• Image:
• Example: examples/PCF85176/T1T2Lcd/

---

4DR821B / 4DT821B (Tesla)

Specifications:

• Segments: Custom Tesla dashboard display
• Features: Multiple symbol zones
• Wiring: I2C (SDA, SCL)
• I2C Address: 0x38 (SA0=0) or 0x39 (SA0=1)
• Controller: PCF85176
• Image:
• Reference: https://www.teslakatalog.cz/4DR821B.html
• Example: examples/PCF85176/4DR821B/

---

4+6 Digit Maint/Bat/Sig/Units

Specifications:

• Digits: 4 digits (main) + 6 digits (status)
• Features: Maintenance, Battery, Signal, Unit symbols
• Wiring: I2C (SDA, SCL)
• Controller: PCF8576 (enhanced variant)
• Image:
• Example: examples/PCF8576/4Seg6SegMaintSegBatUnits/
• Purchase: https://aliexpress.com/item/1005009599538480.html

---

HT1621 (3-Wire Serial) Displays

4-Digit with Degree Symbols

Specifications:

• Digits: 4 7-segment digits
• Features: Degree symbol, Colon for time display
• Wiring: 3 pins (CLK, DATA, CS) + Power + GND
• Protocol: 3-wire serial
• Controller: HT1621 (integrated in module)
• Image:
• Example: examples/HT1621/4DigDeg/
• Purchase: https://aliexpress.com/item/1005009301473702.html

Code Example:

#include "SegTransportArduino.h"
#include "SegLCD_HT1621_4SegDegree.h"
 
const int CLK = 5, DATA = 6, CS = 7;
SegTransport3WireArduino transport(DATA, CLK);
SegLCD_HT1621_4SegDegree lcd(transport, CS);
 
lcd.init();
lcd.setCursor(0, 0);
lcd.print(25);      // Display "25°"

Wiring Example (Arduino Uno):

HT1621 Module  →  Arduino
CLK            →  Pin 5
DATA           →  Pin 6
CS (chip sel)  →  Pin 7
VCC            →  3.3V or 5V
GND            →  GND

---

6-Digit with Battery

Specifications:

• Digits: 6 7-segment digits
• Features: Battery level indicator (3-4 states)
• Wiring: 3 pins (CLK, DATA, CS) + Power + GND
• Protocol: 3-wire serial
• Controller: HT1621 (integrated)
• Image:
• Example: examples/HT1621/6DigBat/
• Purchase: https://www.aliexpress.com/item/1005006419794882.html

Code Example:

#include "SegTransportArduino.h"
#include "SegLCD_HT1621_6SegBat.h"
 
const int CLK = 5, DATA = 6, CS = 7;
SegTransport3WireArduino transport(DATA, CLK);
SegLCD_HT1621_6SegBat lcd(transport, CS);
 
lcd.init();
lcd.print(123456);
lcd.setBatteryLevel(2);  // Medium battery

---

LCM0844

Specifications:

• Digits: 8 7-segment digits
• Features: Left/right units, status labels, battery/load indicators, power-flow symbols
• Wiring: 3 pins (CLK, DATA, CS) + Power + GND
• Protocol: 3-wire serial
• Controller: HT1621 (integrated)
• Image:
• Example: examples/HT1621/LCM0844/
• Purchase: https://www.aliexpress.com/w/wholesale-LCM0844.html

Code Example:

#include "SegTransportArduino.h"
#include "SegLCD_HT1621_LCM0844.h"
 
const int CLK = 5, DATA = 6, CS = 7;
SegTransport3WireArduino transport(DATA, CLK);
SegLCD_HT1621_LCM0844 lcd(transport, CS);
 
lcd.init();
lcd.print("12.34");
lcd.setBatteryLevel(4);
lcd.setLoadLevel(3);

---

LCM88128

Specifications:

• Digits: 8 7-segment digits
• Features: Left/right units, status labels, battery/load/PV indicators, power-flow symbols
• Wiring: 3 pins (CLK, DATA, CS) + Power + GND
• Protocol: 3-wire serial
• Controller: HT1621 (integrated)
• Image:
• Example: examples/HT1621/LCM88128/
• Purchase: (N/A) whzkyd.com

Code Example:

#include "SegTransportArduino.h"
#include "SegLCD_HT1621_LCM88128.h"
 
const int CLK = 5, DATA = 6, CS = 7;
SegTransport3WireArduino transport(DATA, CLK);
SegLCD_HT1621_LCM88128 lcd(transport, CS);
 
lcd.init();
lcd.print("12.34");
lcd.setPVLevel(4);
lcd.setBatteryLevel(3);
lcd.setLoadLevel(2);
lcd.setUnits(SegLCD_HT1621_LCM88128::UNIT_RIGHT_VOLT);
lcd.setSymbols(SegLCD_HT1621_LCM88128::SYMBOL_LINE_WIND_TO_ACDC);

---

LCM59011

Specifications:

• Digits: 4 7-segment digits
• Features: Colon, wifi signal, battery indicator, MCB label, units, status symbols
• Wiring: 3 pins (CLK, DATA, CS) + Power + GND
• Protocol: 3-wire serial
• Controller: HT1621 (integrated)
• Image:
• Example: examples/HT1621/LCM59011/

Code Example:

#include "SegTransportArduino.h"
#include "SegLCD_HT1621_LCM59011.h"
 
const int CLK = 5, DATA = 6, CS = 7;
SegTransport3WireArduino transport(DATA, CLK);
SegLCD_HT1621_LCM59011 lcd(transport, CS);
 
lcd.init();
lcd.print("12:3");
lcd.setSignalLevel(4);
lcd.setBatteryLevel(5);
lcd.setLabels(SegLCD_HT1621_LCM59011::LABEL_MCB);
lcd.setUnits(SegLCD_HT1621_LCM59011::UNIT_PERCENT);
lcd.setSymbols(SegLCD_HT1621_LCM59011::SYMBOL_ECO | SegLCD_HT1621_LCM59011::SYMBOL_BLUETOOTH);

---

RAW LCD (HT1621)

Purpose: Testing and prototyping with HT1621

• Type: Test harness
• Wiring: 3-wire serial (CLK, DATA, CS)
• Features: Send raw segment data to HT1621
• Example: examples/HT1621/RawLCD/

---

HT1622 (3-Wire Serial, Enhanced)

10-Digit 16-Segment Display

Specifications:

• Digits: 10 digits with 16-segment layout
• Features: Enhanced segment capability (alphanumeric capable)
• Wiring: 3 pins (CLK, DATA, CS) + Power + GND
• Protocol: 3-wire serial (4μs timing)
• Controller: HT1622 (integrated, larger RAM)
• Image:
• Example: examples/HT1622/10Digit16SegmentLCD/
• Purchase: https://aliexpress.com/item/1005003062619251.html

---

RAW LCD (HT1622)

Purpose: Testing and prototyping with HT1622

• Type: Test harness
• Wiring: 3-wire serial (CLK, DATA, CS)
• Features: Send raw segment data to HT1622
• Timing: Requires 4μs pulse width
• Example: examples/HT1622/RawLCD/

---

VK0192 (3-Wire Serial)

5-Digit Signal/Battery/Progress

Specifications:

• Digits: 5 7-segment digits
• Features: Signal bars (4), Battery level (3), Progress indicator
• Wiring: 3 pins (CLK, DATA, CS) + Power + GND
• Protocol: 3-wire serial, same protocol/timing family as HT1621/HT1622
• Controller: VK0192 (24×8 bit RAM). This module's digits map to non-sequential RAM addresses due to its SEG/COM pin layout — a property of this specific display, not the VK0192 controller.
• Image:
• Example: examples/VK0192/5DigSigBattProgress/
• Purchase: https://aliexpress.com/item/1005009000021475.html

Code Example:

#include "SegTransportArduino.h"
#include "SegLCD_VK0192_5DigSigBattProgress.h"
 
const int CLK = 5, DATA = 6, CS = 7;
SegTransport3WireArduino transport(DATA, CLK);
SegLCD_VK0192_5DigSigBattProgress lcd(transport, CS);
 
lcd.init();
lcd.print(12345);
lcd.setSignalLevel(3);    // 3 of 4 bars
lcd.setBatteryLevel(1);   // Low battery

---

Quick Comparison

Controller	Protocol	Pins	I2C Addr	Examples	Complexity
PCF85134	I2C	2	0x38/0x39	2	Simple
PCF85176	I2C	2	0x38/0x39	7	Simple
PCF8576	I2C	2	0x38/0x39	1	Simple
HT1621	3-wire	3	N/A	4	Medium
HT1622	3-wire	3	N/A	2	Medium
VK0192	3-wire	3	N/A	1	Medium

Adding a New Display

Don't see your LCD? Follow the Adding New LCD guide to create support for any segment display.

Resources

• Getting Started: Getting Started Guide
• Architecture: Library Architecture
• Controller Details: Controllers
• Creating Drivers: Adding New LCD
• API Reference: Full API Documentation