Table of Contents

Lp3943 LED driver

The LP3943 is an integrated device capable of independently driving 16 LEDs. It uses I2C.

Documentation

Lp3943 eval board example back side Lp3943 eval board example front side

Usage

Important: make sure you properly setup the I2C pins especially for ESP32 before creating the I2cDevice, make sure you install the nanoFramework.Hardware.ESP32 nuget:

//////////////////////////////////////////////////////////////////////
// when connecting to an ESP32 device, need to configure the I2C GPIOs
// used for the bus
Configuration.SetPinFunction(21, DeviceFunction.I2C1_DATA);
Configuration.SetPinFunction(22, DeviceFunction.I2C1_CLOCK);

For other devices like STM32, please make sure you're using the preset pins for the I2C bus you want to use.

I2cConnectionSettings settings = new I2cConnectionSettings(1, Lp3943.DefaultI2cAddress);
I2cDevice device = I2cDevice.Create(settings);

using var ledDriver = new Lp3943(device, resetPin);

// Dim LEDs 0 to 7 at 1 Hz at 25% duty cycle
ledDriver.DimRegister(DimRegister.Dim0, 1, 25);

// Dim LEDs 8 to 15 at 5 Hz at 50% duty cycle
ledDriver.DimRegister(DimRegister.Dim1, 5, 50);

// Set LEDs 12, 13, 14, 15 off
ledDriver.SetLed(
	new[] { 12, 13, 14, 15 },
	LedState.Off
);

// Set LEDs 0, 1, 2, 3, 4, 5 on
ledDriver.SetLed(
	new[] { 0, 1, 2, 3, 4, 5 },
	LedState.On
);

// Set LEDs 6, 7, 8 to be powered by Dim register 0
ledDriver.SetLed(
	new[] { 6, 7, 8 },
	LedState.Dim0
);

// Set LEDs 9, 10, 11 to be powered by Dim register 1
ledDriver.SetLed(9, LedState.Dim1);
ledDriver.SetLed(10, LedState.Dim1);
ledDriver.SetLed(11, LedState.Dim1);