Arduino Nano 33 - Minimal Dimmer Implementation

This minimal hardware timer implementation works out of the box for all Arduino Nano 33 boards:

• Arduino Nano 33 IoT
• Arduino Nano 33 BLE
• Arduino Nano 33 BLE Sense

Setup

Connect the Arduino to a suitable AC dimmer module, e.g. the RobotDyn® 4-channel AC dimmer:

Arduino	Dimmer
GND	GND	R
3.3V	VCC	R
D2	Z-C	R
D3	D1	O
D4	D2	O
D5	D3	O
D6	D4	O

R indicates a required and O an optional connection.

Usage

Comment out #define NETWORK_FREQUENCY_50HZ if your network frequency is 60Hz or leave it as is for 50Hz. Enable the desired lights using the ENABLED_LIGHTS_MASK bitmask, e.g.:

#define ENABLED_LIGHTS_MASK (LIGHT_D3 | LIGHT_D4 | LIGHT_D5)

Set a light's brightness by calling:

set_brightness(&light_D4, 150);

This implementation relies on TIMER3_IRQn or TC3_IRQn respectively so please make sure these timers are free.

Do not add any Serial.print() calls to the interrupt service routines zc_isr() and IRQ_HANDLER() since this will most likely result in a stalled CPU.