StoneLCDLib

This library is intended to make it easier to use the STONE LCD HMI Displays with Arduino-compatible boards.

For the time being it comes with an equivalent to the RGB LED Strip Example that comes with the LCD screens.

This library currently has the following features:

• Read and write to/from LCD registers
• Read and write to/from User-defined variables.
• Receive events from the LCD.
• Read, Write and Parse the on-board RTC clock data.

Missing Features

The following is a short list of pending work:

• Support for CRC checks
• Functions to use the graph/curve buffer
• [*] High level functions for video playback
• [*] High level functions for reading touchscreen data

With the exception of the first two items, all of the remaining features are controlled by LCD registers, so they can be performed with the already existing functions in this library. I hope, however, to add more methods especifically designed to access those features in a friendlier way.

Compatibility

This library doesn't use any device-specific feature, so it should be compatible with all the devices supported by the base Arduino framework. Having said that, it has only been tested with AVR-based Arduino boards.

Usage

Once installed, add this line to the top of your Arduino sketch:

#include <StoneLCDLib.h>

1. Initialization

Initialize the Library by creating a StoneLCD object, passing the serial port it's connected to:

StoneLCD myLCD(&Serial);

Serial can be a Serial port implementation that complies with Arduino's Stream interface. This means that you can also use a SoftSerial port, if care is taken to constantly check for incoming bytes.

You can also specify the command packet Lo/Hi bytes when you initialize the LCD:

StoneLCD myLCD(&Serial, 0xA5, 0x5A);

2. Reading / Writing LCD Registers

The current functions are used to work with the LCD registers:

• writeRegister (regStartAddr, *buffer, buffLen)
• writeRegisterByte (regStartAddr, b)
• writeRegisterWord (regStartAddr, w)
• readRegister (regStartAddr, *dest_buffer, buffLen)
• readRegisterByte (regStartAddr)
• readRegisterWord (regStartAddr)

These should be sufficient to set or retrieve LCD parameters, and control features like media playback, Touchscreen, RTC clock, etc.

StoneLCDLib.h also contains definitions for the addresses of all registers (e.g: STONE_REG_TP_STATUS, STONE_REG_RUNTIME, STONE_REG_VOL, etc). Check the file for a list of available constants.

3. Reading / Writing Variables

User variables can be accessed through the following methods:

• writeVariable (varStartAddr, *buffer, buffLen)
• writeVariableWord (varStartAddr, w)
• readVariable (varStartAddr, *dest_buffer, buffLen)
• readVariableWord (varStartAddr)

4. Current Page (Picture)

The current Page picture can be queried or set with:

• setCurrentPage (picId)
• getCurrentPage()

4. Audio

The current functions for audio are implemented:

• playSound(soundId, volume)
• stopSound(soundId)
• getSoundPlaybackStatus()

6. RTC

You can access the RTC through the registers directly, but this library provides an abstraction class plus read/write methods so you can handle the RTC Date/Time data easily.

Methods:

• getRTC (*StoneLCDDateTime)
• setRTC (*StoneLCDDateTime)

The StoneLCDDateTime provides the following functionality:

• getYear()
• getMonth()
• getDay()
• getWeek()
• getHour()
• getMinutes()
• getSeconds()
• setYear(y)
• setMonth(m)
• setDay(d)
• setWeek(w)
• setHour(h)
• setMinutes(m)
• setSeconds(s)

7. Receiving events from the screen

Make sure that you are constantly calling checkForIOEvents() somewhere in your main loop. When you call this function you'll need to specify a buffer for the event data, and a pointer to a StoneLCDEvent object that will receive the basic event information, like this:

StoneLCDEvent evt;
uint16_t recvBuffer[8];
boolean recvEvent;

recvEvent = myLCD.checkForIOEvent(&evt, recvBuffer, 8);

For the time being the StoneLCDEvent structure has the following definition:

typedef struct {
  uint8_t cmd;      // Command type. Normally a variable operation.
  uint16_t address; // Variable address or element Id associated to the event
  uint8_t dataLen;  // Length of data received (and written to the provided buffer)
} StoneLCDEvent;