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Table of Contents
B4: Handling LED brightness using PWM via I2C controller
This is the simple example of setting brightness of LED using PWM controller.
Target group
This hands-on lab guide is intended for the Beginners.
Prerequisites
The user needs to know: Basic knowledge of ESP8266 NodeMCU v.2. ESP8266 Arduino programming, Basic knowledge of I2C Interface. Basic knowledge of I2C programming using Arduino I2C library.
Scenario
All important information including the address of devices is enclosed in the description of the laboratory. In that scenario, the user should write a program in the Arduino platform which turns on and off LEDs for the specified time 15 seconds. The LEDs brightness can be controlled by setting variable “level” from 0 to 4095.
Result
As a result user can control in cameras program execution.
Start
In the beginning, both cameras must show that all LEDs are off. Steps
Step 1
First load an example project, include appropriate libraries and declare variable ledDriver #include <Wire.h> #include <PCA9685.h>
PCA9685 ledDriver;
Step 2
Please scan I2C bus and check if PWM controller is present.
Step 3
Write a programme which:
- Turn LED1 placed on the dark side to warm-white fully on for 15 seconds
- Turn LED1 off
- Turn LED1 to cold-white fully on for 15 seconds
- Turn lED1 off
- Turn LED2 placed on the bright side to warm-white fully on for 15 seconds
- Turn LED2 off
- Turn LED2 to cold-white fully on for 15 seconds
- Turn lED2 off
ledDriver.setLEDDimmed(number,level)
Step 4
Repeat step 3 ten times.
Result validation
The only way for validation is to check display by the camera. Both cameras must show that LEDs are changing brightness in given periods of time.
FAQ
