Free Pascal Hardware abstraction library for the Raspberry Pi

https://github.com/rudiratlos/rpi-hal

rpi-hal-master.zip

rpi_hal

Free Pascal Hardware abstraction library for the Raspberry Pi
This Unit, with more than 7500 Lines of Code,
delivers procedures and functions to access the rpi HW

• I2C
• SPI
• GPIO (input, output, SW-PWM, HW-PWM, timer, frequency output)
• Bitbang functions for Powerswitches (ELRO, Intertechno, Sartano, Nexa)
• Morse functions
• Rotational Encoders implemented with Threads (e.g. Keyes KY-040 Rotary Encoder)
• Servo functions
• PID Algorithmus
• functions to access PiFace Board
• Bidirectional serial device access in User space /dev/yourdevice
• USB Reset and Access
• Maintain INI-Files for parameter management
• RPI HAT access
• Thread Management
• Timing functions (e.g. SetTimeOut, TimeElapsed)
• StringManipulation (e.g. Select_Item for handling .csv files)
• call external OS program and receive answer with multiple lines (e.g. directory list)
• extensive Logging functions
• CURL wrapper
• SW Maintenance-/Service-functions:
  Upload Logfiles to FTP-Server
  Download new SW from FTP-Server
  Install new SW on rpi
• many examples, how to use the rpi_hal

!! Since V4.5 new startup strategy, rpi_hal will not bring up HW automatically.
!! pls. start rpi_hal with e.g. RPI_HW_Start for all components in your main program,
!! or use explicit flags: RPI_HW_Start([InitHaltOnError,InitGPIO,InitI2C,InitSPI])

Discussion forum: http://forum.lazarus.freepascal.org/index.php/topic,20991.75.html

Just an excerpt of the available functions and procedures:

GPIO Functions:

• procedure gpio_set_pin (pin:longword;highlevel:boolean); // Set RPi GPIO pin to high or low level
• function gpio_get_PIN (pin:longword):boolean; // Get RPi GPIO pin Level is true when Pin level is '1'; false when '0'
• procedure gpio_set_input (pin:longword); // Set RPi GPIO pin to input direction
• procedure gpio_set_output(pin:longword); // Set RPi GPIO pin to output direction
• procedure gpio_set_alt (pin,altfunc:longword); // Set RPi GPIO pin to alternate function nr. 0..5
• procedure gpio_set_gppud (mask:longword); // set RPi GPIO Pull-up/down Register (GPPUD) with mask

General Functions:

• function rpi_snr:string; // delivers SNR: 0000000012345678
• function rpi_hw:string; // delivers Processor Type: BCM2708, BCM2709 or BCM2835

I2C Functions:

• function i2c_bus_write(baseadr,reg:word; var data:databuf_t; lgt:byte; testnr:integer) : integer;
• function i2c_bus_read (baseadr,reg:word; var data:databuf_t; lgt:byte; testnr:integer) : integer;
• function i2c_string_read(baseadr,reg:word; var data:databuf_t; lgt:byte; testnr:integer) : string;
• function i2c_string_write(baseadr,reg:word; s:string; testnr:integer) : integer;

SPI Functions:

• procedure SPI_Write(devnum:byte; reg,data:word);
• function SPI_Read(devnum:byte; reg:word) : byte;
• procedure SPI_BurstRead2Buffer (devnum,start_reg:byte; xferlen:longword);
• procedure SPI_BurstWriteBuffer (devnum,start_reg:byte; xferlen:longword);