README

UnoLib

UnoLib is a Pascal library designed for the Arduino Uno platform and AVRPascal or other editor using FPC 3.3.1 for AVR microcontrollers (e.g. FreePascal IDE, Lazarus). It is a translation of a subset of the standard Arduino libraries, adapted as needed for a Pascal environment. Moreover, support for fixed-point and floating-point numbers has been added.

Written by @ackarwow in collaboration with @Dzandaa (from 2024). Licensed under the MIT License. See LICENSE.txt for details.

Library modules included:

• analog.pas - support for analog pins
• defs.pas - definitions of constants, bit manipulations, port support
• dht.pas - support for DHT11/22 sensors
• digital.pas - support for digital pins
• ds1302rtc.pas - support for DS1302 real time clock
• fix16.pas - support for fixed point numbers
• float32.pas - support for floating point numbers, basic arithmetic and trigonometric operations (in collaboration with @Dzandaa)
• hardwareserial.pas - support for serial communication
• i2c.pas - support for I2C communication bus (by @Dzandaa, many thanks to @ccrause)
• liquidcrystal.pas - support for LCD
• pulse.pas - routines for reading a pulse on a pin (additional function written by @Dzandaa returns length of the pulse in milliseconds)
• spi.pas - support for SPI
• stringutils.pas - string conversion routines (by @Dzandaa)
• timer.pas - time-related routines
• tone.pas - square wave tone routines

The library modules are located in the "lib" directory.

Documentation is placed in "docs" directory:

• ArduinoISP.pdf - documentation for ArduinoISP.pas example
• analog.pdf - documentation for analog.pas unit
• defs.pdf - documentation for defs.pas unit
• dht.pdf - documentation for dht.pas unit
• digital.pdf - documentation for digital.pas unit
• ds1302rtc.pdf - documentation for ds1302rtc.pas unit
• fix16.pdf - documentation for fix16.pas unit
• float32.pdf - documentation for float32.pas unit
• hardwareserial.pdf - documentation for hardwareserial.pas unit
• liquidcrystal.pdf - documentation for liquidcrystal.pas unit
• pulse.pdf - documentation for pulse.pas unit
• spi.pdf - documentation for spi.pas unit
• stringutils.pdf - documentation for stringutils.pas unit
• timer.pdf - documentation for timer.pas unit
• tone.pdf - documentation for tone.pas unit
• UnoLib_HowToStart.pdf - guide for beginners

The "examples" directory contains simple sample programs using UnoLib modules:

• ArduinoISP.pas - simple ISP programmer
• DS137ZN_RTC_Test.pas - Real Time Clock test using I2C (by @Dzandaa)
• HMC5883L_Magnetometer_Test.pas - HMC5883L Magnetometer test using I2C (by @Dzandaa)
• I2CScan.pas - I2C bus scan (by @Dzandaa)
• pcf8591t_ACDC_Read.pas - AC/DC read test (by @Dzandaa)
• pcf8591t_ACDC_Write.pas - AC/DC write test (by @Dzandaa)
• TestBlink.pas - turns on and off the built-in LED
• TestBlinkWithoutDelay.pas - turns on and off the built-in LED using Millis
• TestDHT11.pas - displays temperature and humidity from a DHT11 sensor on an LCD display
• TestDigital.pas - turns on and off the built-in LED based on the button state
• TestHC-SR04.pas - example of using HC-SR04 ultrasonic sensor
• TestILI9163.pas - example of using SPI with an ILI9163 TFT display
• TestLCAutoscroll.pas - scrolls text on the LCD display
• TestLCBlink.pas - displays the text "hello, world!" on the LCD display
• TestLCChars.pas - displays non-standard characters on the LCD display
• TestLCCursor.pas - turns the cursor on and off on the LCD display
• TestLCDisplay.pas - displays and turns off the text "hello, world!"
• TestLCSerialDisplay.pas - displays characters taken from the serial port on the LCD

display

• TestLCTextDirection.pas - changes the direction of text display on the LCD display
• TestLM35.pas - displays the temperature value from the LM35 sensor on the LCD

display

• TestSerial.pas - sends and receives data via the serial port
• TestTone.pas - plays a melody using _tone routine

Some extra code is placed in "extras" directory:

• ccrause_blink_leonardo.pas - blink example for Arduino Leonardo based on code written by @ccrause
• ccrause_delay.pas - delay module based on code written by @ccrause
• ccrause_test_leonardo.pas - serial communication example for Arduino Leonardo based on code written by @ccrause
• cdc.pas - CDC support for Arduino Leonardo
• debug_leonardo.pas - simple LED-based debug code
• usb.pas - USB support for Arduino Leonardo
• wdt.pas - watchdog timer routines

Lazarus test projects are placed in "tests" directory:

• conversion - routines for numeric and string conversion and data preparation for CORDIC algorithm (by @Dzandaa with collaboration of @ackarwow)
• float32 - test programs for testing TFloat32 type both on Lazarus and on Arduino side (based on serial port communication program by @Dzandaa)
• serial - serial port communication test (by @Dzandaa)

Before compiling a given program, make sure that the library modules listed in the uses section have already been compiled.

Notice: UnoLib is distributed for educational and experimental use with microcontrollers. It is not intended for safety-critical or life-support systems.

Changes

version 1.3 - 23/06/2026 (AVRPascal 3.8)

• added ArduinoISP.pas simple programmer example (thanks to Christof Biner for the suggestion)
• added SPI support (spi.pas) and TestILI9163.pas example
• updated stringutils.pas and defs.pas
• made minor changes in fix16.pas

version 1.2 - 11/11/2025 (AVRPascal 3.4)

• added the ability to use standard operators (+, -, *, /) directly with the TFloat32 type (by @Dzandaa)
• added new string conversion routines for TFloat32 (by @Dzandaa and @ackarwow)
• added new "docs" directory containing documentation (PDF files) for most library modules and the How to start guide for beginners

version 1.1 - 16/08/2025 (AVRPascal 3.3)

• fixes in support for Arduino Leonardo

Many thanks to @ccrause for his suggestions and help

version 1.0 - 28/07/2025

• added square wave tone routines and example (ToneNoInt by @Myel)
• added pulsein routines and example (pulseInMilli by @Dzandaa)
• added i2c module and examples of its use (by @Dzandaa)
• added sine table generation for conv2hexa (by @Dzandaa)

version 0.9 - 21/01/2025 (AVRPascal 3.1)

• added float32.pas module supporting 32-bit floating point numbers (in collaboration with @Dzandaa)
• added test programs for serial communication, TFloat32, and conversions, placed in "tests" folder (written by @Dzandaa, some of them modified by @ackarwow)

@Dzandaa started collaborating on the development of UnoLib.

version 0.8 - 09/12/2024 (AVRPascal 3.0)

• added extra code for Arduino Leonardo ("extras" directory)
• modified $IFDEF conditionals for compatibility with FPC 3.3.1 defines
• inlined routines in defs.pas and timer.pas
• added default result of functions in defs.pas
• added THardwareSerial.ReadByte in hardwareserial.pas
• added Fix16Sqrt routine in fix16.pas

Thanks to @Dzandaa for suggestions and implementation of THardwareSerial.ReadByte

version 0.7 - 18/11/2024 (AVRPascal 2.9)

Changes in hardwareserial.pas:

• added THardwareSerial.WriteBuff for writing buffer of bytes
• added THardwareSerial.ReadBuff for reading buffer of bytes
• THardwareSerial._begin renamed to THardwareSerial.Start, THardwareSerial._end renamed to THardwareSerial.Stop
• added THardwareSerial.Read for Arduino compatibility

Many thanks to @Dzandaa, @ccrause, and @VisualLab for suggestions and discussion

version 0.6 - 19/10/2024 (AVRPascal 2.6)

• changed conditional directive, added arduinonano
• fixed problem with millisecond counter in lib\timer.pas
• added examples\TestBlinkWithoutDelay.pas

Thanks to Henk Heemstra for source code of TestBlinkWithoutDelay.pas

version 0.5 - 18/07/2024 (AVRPascal 2.0)

• changed conditional directive, atmega328p or arduinouno required

version 0.4 - 31/10/2023 (AVRPascal 1.2)

• added conditional compilation directive {ifndef} for atmega328p; requires AVRPascal installed

version 0.3 - 28/09/2023 (AVRPascal 1.0)

• minor technical changes

version 0.2 - 18/04/2022

• added hardwareserial.pas module

version 0.1 - 06/01/2022

• primary version