Script Editor: Change duty ratio of a clock pattern every cycle

gupta · November 9, 2020

Hello, I am a new user of Analog Discovery 2 device. I would like to output a pattern at DIO1 (for example) wherein the duty ratio is selected from a look-up table. I am trying to use the Script Editor. However, I am unsure what function/variable I should use to increment the index for the look-up table such that at the beginning of every cycle, the clock has the updated duty ratio. Here is a snapshot of my dummy code:

clear()

if(!('Patterns' in this)) throw "Please open a Patterns instrument";

var values = [10, 20, 30, 40, 50, 60, 70, 80, 90, 95];

Patterns.run();

for(var idx = 0; idx < 10; idx++){

	var d = values[idx];

	wait(FOR AN EDGE-TRIGGER OR SOME SIMILAR CLOCK EVENT) // I am unsure if wait is the correct choice. 

	Patterns.Channels.DIO1.Duty.value = d;

	idx = idx+1;

}

// Assuming that DIO1 has a set frequency of 1kHz, the duty should change from 10% to 95% every 1kHz in steps as listed in variable 'values'.

Any insights would be helpful.

JColvin · November 10, 2020

Hi @gupta,

I have moved your question to a more appropriate section of the forum where the engineer most familiar with the WaveForms software will be able to see and respond to your question.

Thanks,
JColvin

attila · November 11, 2020

Hi @gupta

You can create a custom pattern with such duty factors.

With the default configuration of AD2 you have 1ki samples for such custom pattern but with the 4th device configuration up to 16ki.

The pattern can be created in WaveForms Pattern Custom Editor, external spreadsheet editor exported/imported csv, or with the Script tool like this:

var duty = [10, 20, 30, 40, 50, 60, 70, 80, 90, 95];
var data = []
const res = 20
duty.forEach(function(d){ for(var i = 0; i < res; i++) data.push(i>=res*d/100?0:1)})
Patterns.Channels.DIO1.custom = data

if(Patterns.Channels.DIO1.custom.length!=data.length) print("too many samples",data.length)
else print("done", data.length)