Spyglass Control Panel UI Board Driver (spyglass.c)
[Drivers (for external hardware)]

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Detailed Description

        #include "lcd.h"
        #include "i2c.h"
        #include "spyglass.h"

Overview

This library supports the 'Spyglass' I2C-controlled User Interface board. The Spyglass board has a standard 4x20 character LCD and a convenient array of pushbuttons for a user interface. The board also has a user-controllable piezo beeper. All of these functions are accessible via I2C bus, making it possible to have a complete user interface with just 4 wires (2 I/O and 2 power wires). The Spyglass board runs on 5V power.

Connections:

• Connect power to the +5V and ground pins.
• Connect the SCL/SDA pins to the corresponding SCL/SDA pins of your processor's I2C bus.
• If you wish to use the beeper, also connect +5V to pin 8.

     SPYGLASS PINOUT for 10-pin I/O header:
   
                ----
        +5V - 1 |++| 2 - +5V
        SCL - 3 |++| 4 - GND
        SDA - 5 |++| 6 - GND
              7 |++| 8 - BEEPER PWR (+5V)
              9 |++| 10
                ----

Defines
#define	PCF8574_I2C_BASE_ADDR   0x40
#define	MAX517_I2C_BASE_ADDR   0x58
#define	PCF_NODE_BUTTONS   0x00
#define	PCF_NODE_LCD_DATA   0x01
#define	PCF_NODE_CONTROL   0x02
#define	SPYGLASS_LED0   0x01
#define	SPYGLASS_LED1   0x02
#define	SPYGLASS_BEEPER   0x04
#define	SPYGLASS_LCD_RS   0x20
#define	SPYGLASS_LCD_RW   0x40
#define	SPYGLASS_LCD_E   0x80
#define	lcdInit   spyglassLcdInit
#define	lcdHome   spyglassLcdHome
#define	lcdClear   spyglassLcdClear
#define	lcdGotoXY   spyglassLcdGotoXY
#define	lcdDataWrite   spyglassLcdWriteChar
Functions
void	spyglassInit (void)
	initialize the I2C bus for communication with the spyglass UI.
u08	spyglassGetPushbuttons (void)
void	spyglassSetLeds (u08 leds)
void	spyglassSetBeeper (u08 state)
u08	spyglassSetLcdContrast (u08 contrast)
void	spyglassLcdInit (void)
	Initialize LCD for operation.
void	spyglassLcdHome (void)
	Set write/cursor position to upper left.
void	spyglassLcdClear (void)
	Clear LCD display.
void	spyglassLcdGotoXY (u08 x, u08 y)
	Set write/cursor posision on LCD display (x=col, y=line).
void	spyglassLcdWrite (u08 rs, u08 data)
	Write control or display data to LCD.
void	spyglassLcdWriteChar (u08 c)
	Write character to LCD.
u08	pcf8574Write (u08 nodeAddr, u08 data)
	Write I/O Data to PCF8574 I2C<->Digital I/O chip.
u08	pcf8574Read (u08 nodeAddr)
	Read I/O Data from PCF8574 I2C<->Digital I/O chip.

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Function Documentation

u08 spyglassGetPushbuttons (  void   )

Read the state of pushbuttons on the spyglass UI. Returns an 8-bit number representing the state of buttons S1-S7 in bits 0-6 respectively. '0' bit value = button not pressed '1' bit value = button is pressed Definition at line 51 of file spyglass.c.

void spyglassSetBeeper (  u08  state  )

Sets the state of the beeper on the spyglass UI. '0' state => beeper off '1' state => beeper on Definition at line 62 of file spyglass.c.

u08 spyglassSetLcdContrast (  u08  contrast  )

Sets the contrast voltage of the spyglass LCD. Lower numbers are darker contrast, higher numbers are lighter contrast. Definition at line 71 of file spyglass.c.

void spyglassSetLeds (  u08  leds  )

Sets the state of LEDs on the spyglass UI. Argument is a 2-bit number representing the desired state of LEDs D2 & D3 respectively. '0' bit value = LED off '1' bit value = LED on Definition at line 56 of file spyglass.c.

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