aliffers / i2c_rl8xxm Goto Github PK

Small and simple library for I2C-RL812M, I2C-RL812MA, I2C-RL824M, I2C-RL824MA
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The only differences between the various models of I2C relay boards from ereshop.com, is the addressing (M vs. MA)
and voltage (812 = 12V and 824 = 24V).

The functions don't do any checking regarding whether or not the addressing is right, or anything else.  They're
written for speed and minimal code size.

All functions that switch relays on have a built in 10ms delay to allow the mechanics of the relay to flip.  Similarly
for switching off there's a 5ms delay.  For the toggle functions, rather than wasting time looking up whether it is an
on or off action, the delay is simply 10ms.

To use the library, include the library and Wire.h:
#include <Wire.h>
#include <I2C_RL8xxM.h>

You will need to manually activate I2C in your Arduino sketch.  Rather than enabling it in the constructor of this
class, and disabling in the destructor, I left it up the individual user to enable/disable I2C as they see fit.
There's a chance that these relay boards aren't the only I2C devices on the bus.

To create an instance of the class, use the constructor and pass the address of the board as the only parameter:
I2C_RL8xxM rb (0x20);

Example Usage
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rb.Switch (1, true); // Switch relay 1 on (true = on, false = off)
rb.Switch (2, false); // Switch relay 2 off
rb.Toggle (3); // Toggle relay 3, to the opposite of whatever it is now
rb.Toggle (0); // Toggle all relays to the opposite of whatever they are now

Functions
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For all functions specifying a relay number, the values are 1 through to 8.

1. Main functions

bool IsOn (int relay); // Returns true if "relay" is on, otherwise false.
void Switch (int relay, bool on); // Switches "relay" on if "on" is true, otherwise off.
void Toggle (int relay); // Toggles "relay" to the opposite of the current value. If "relay" is zero, all relays are toggled.
void All (bool on); // Switch all relays on if "on" is true, otherwise off.

2. Shortcut functions
void On (int relay); // Switches "relay" on.
void Off (int relay); // Switches "relay" off.
void AllOn (); // All relays on.
void AllOff (); // All relays off.
void AllToggle (); // Toggle all relays.

3. Internal functions

These functions are used internally by the class, but I've made them publicly accessible just for fun.

byte ReadValue (); // Returns the current value of PCF8574, which handles the I2C communications.
void WriteValue (byte value); // Writes "value" to the PCF8574.