PWM Library

Projects Programming
1

Hello. I am planning a project which requires more than six PWM pins. I tried installing the PWM library from Github. but got this message;
The library "Arduino PWM Frequency Library v_05" cannot be used.
Library names must contain only basic letters and numbers.
(ASCII only and no spaces, and it cannot start with a number)
I tried renaming the library with no spaces and got this message;
Arduino: 1.8.13 (Windows 10), Board: "Arduino Nano, ATmega328P"
Specified folder/zip file does not contain a valid library.

Does anyone know where I could find another PWM library or what I'm doing wrong?

2

I don't think the PWM Frequency Library will get you more PWM outputs. It will let you control the frequency on, probably, two of the 6 PWM pins.

How many more than 6 PWM pins do you need? The Arduino MEGA has 15 PWM pins.

You can add an Adafruit PWM shield (Adafruit 16-Channel 12-bit PWM/Servo Shield - I2C interface : ID 1411 : $17.50 : Adafruit Industries, Unique & fun DIY electronics and kits) to get 16 PWM pins with 12-bit (4096-level) PWM rather than the native Arduino UNO 256-level PWM.

3

Thanks, John.
My idea requires 9 or 10 PWM pins. The MEGA would not fit in the space I have. I may try to get the Uno and Uno shield you mentioned to fit but I think I need to change my design.

4

There is the Mega Pro. Smaller than an Uno.

1024×862 225 KB

5

I PWM frequency is not very high it's possible to do a software PWM on each output pin.

6

Polliwog:
Hello. I am planning a project which requires more than six PWM pins. I tried installing the PWM library from Github. but got this message;

Could you provide more details about your setup and requirements for PWM?

7

Thanks for your help and I karma,d you. Pgm not complete but my idea needed 9 PWM LEDs. faded at different times I'll have to come up with another idea

8

alesam:
I PWM frequency is not very high

True: 490 or 977 Hz.

alesam:
it's possible to do a software PWM on each output pin.

But keep in mind that interrupts may cause timing problems!

9

You can use an addressable LEDs like Amazon.com

Only one pin is required to independently drive all of them

10

Erik_Baas:
True: 490 or 977 Hz.

But keep in mind that interrupts may cause timing problems!

  • 490 or 977 Hz. are default values but some application required higher frequency
  • In many cases you can disable all other interrupts
  • For LED brightness control intermittent timing problems are not important.
11

You can try one of these examples to see if OK for your use-case

  1. FakeAnalogWrite
  2. FakeAnalogWrite

They are written to simulate PWM by using TimerInterrupt. You can

  1. modify the ISR frequency to meet your purpose.
  2. re-calibrate and update the mappingTable if need higher accuracy