Migration Guide

This guide documents user-visible changes required when upgrading between SegLCDLib versions.

v0.0.1 to v0.0.2

Migration checklist:

• Transport layer
• PCx85 raw class split
• Labels renamed to units
• Direct driver includes
• Custom LCD implementations
• Backlight initialization

Transport layer

LCD constructors no longer take Arduino Wire or GPIO pins directly. Create a transport object and pass it to the LCD class.

Old:

#include "SegLCD_PCF85176_OneDigit.h"
#include <Wire.h>
 
SegLCD_PCF85176_OneDigit lcd(Wire);

New:

#include "SegTransportArduino.h"
#include "SegLCD_PCF85176_OneDigit.h"
#include <Wire.h>
 
SegTransportI2CArduino transport(Wire);
SegLCD_PCF85176_OneDigit lcd(transport);

For 3-wire controllers:

#include "SegTransportArduino.h"
#include "SegLCD_HT1621_4SegDegree.h"
 
SegTransport3WireArduino transport(6, 5);  // DATA, WR
SegLCD_HT1621_4SegDegree lcd(transport, 7);  // CS

This affects all existing v0.0.1 LCD constructors:

• PCx85 I2C LCDs changed from TwoWire& to SegTransportI2C&
• HT1621/HT1622/VK0192 LCDs changed from direct GPIO pins to SegTransport3Wire& plus chip-select

PCx85 raw class split

The generic SegLCD_PCx85_Raw class was replaced by controller-specific raw classes.

Old:

#include "SegLCD_PCx85_Raw.h"
 
SegLCD_PCx85_Raw lcd(Wire);

New for PCF85176/PCF8576:

#include "SegTransportArduino.h"
#include "SegLCD_PCF85176_Raw.h"
 
SegTransportI2CArduino transport(Wire);
SegLCD_PCF85176_Raw lcd(transport);

Use SegLCD_PCF85134_Raw for PCF85134 displays.

Labels renamed to units

Physical measurement indicators were renamed from labels to units.

v0.0.1	v0.0.2
LabelFlags	UnitFlags
setLabels(...)	setUnits(...)
clearLabels(...)	clearUnits(...)
LABEL_* unit constants	UNIT_* constants

Affected LCD classes:

• SegLCD_PCF85176_TempHumidity
• SegLCD_PCF85176_6DigitSignalBatteryProgress
• SegLCD_PCF85176_T1T2Lcd
• SegLCD_PCF8576_4Seg6SegMaintSegBatUnits
• SegLCD_VK0192_5DigSigBattProgress for unit indicators only

Example:

// Old
lcd.setLabels(SegLCD_PCF85176_TempHumidity::LABEL_DEGREE_C |
              SegLCD_PCF85176_TempHumidity::LABEL_PROC);
 
// New
lcd.setUnits(SegLCD_PCF85176_TempHumidity::UNIT_DEGREE_C |
             SegLCD_PCF85176_TempHumidity::UNIT_PERCENT);

Display text labels remain labels. For example, SegLCD_PCF85176_T1T2Lcd::setT1T2Labels(...) and HT1621 LCM label APIs are unchanged.

Direct driver includes

SegDriver_PCF85176 and SegDriver_PCF8576 moved out of SegDriver_PCx85.h into their own headers.

If user code includes controller drivers directly, update includes:

#include "SegDriver_PCF85176.h"
#include "SegDriver_PCF8576.h"

Regular LCD model headers already include the correct controller header.

Custom LCD implementations

Custom LCD classes derived from library drivers must be updated for the transport layer.

• I2C custom drivers should inherit from the specific controller driver, such as SegDriver_PCF85176.
• 3-wire custom drivers should inherit from the specific controller driver, such as SegDriver_HT1621, SegDriver_HT1622, or SegDriver_VK0192.
• Old global controller macros such as MAX_ADDRESS / MAX_HW_ADDRESS were replaced by class-scoped constants.

Backlight initialization

initBacklight() no longer takes a raw GPIO pin number. Create a SegBacklight implementation and pass it in instead. The active-high flag moved to the backlight implementation's constructor.

Old:

lcd.initBacklight(7, SegLCDLib::BACKLIGHT_DIGITAL, true);

New:

#include "SegBacklightArduino.h"
 
SegBacklightArduino backlight(7);  // activeHigh defaults to true
lcd.initBacklight(&backlight, SegLCDLib::BACKLIGHT_DIGITAL);

If initBacklight() was called conditionally based on a "no backlight" sentinel pin value, keep the SegBacklightArduino instance around only when a real pin is configured (see examples/HT1622/10Digit16SegmentLCD for a static-pin example, or examples/MenuControl/MenuControl.cpp for a dynamically-configured pin using new/delete).