Serial

[ManuelLevi]

I edited the code a bit so now it supports serial communication too.

I can't really test how efficient it is as I only have a small 8 LED ring (this is my first time testing the ws2812b chips).

If anyone is interested, I can make a pull request with the Arduino sketch and code modifications.

[deepak-divakar]

I would love to test this. Can u please share the sketch?

[ManuelLevi]

The sketch is a modified version of LedStripColorTester of the PololuLedStrip lib.

rgb_color color;
current_led = Serial.parseInt();
color.red = Serial.parseInt();
color.green = Serial.parseInt();
color.blue = Serial.parseInt();
colors[current_led] = color;
current_led +=1;
current_led = current_led % LED_COUNT;
ledStrip.write(colors, LED_COUNT);

It receives a string with four integers, the number of the LED, and the values for RGB.

I'm confident this is not the most efficient way to implement as we should only need to send 4 bytes. One byte for each int.

I decided not to care too much about this optimization as with 8 LED's it seems to be working with no major problems.

[joeybab3]

Do you have the python part?

[ManuelLevi]

Yes. It's quite simple.
This would be the most important function.

def _update_serial():
    global pixels
    pixels2 = np.clip(pixels, 0, 255).astype(int)
    for i in range(8):
        tmp = pixels2[:,i]
        s = '{},{},{},{}!'.format(i,tmp[0],tmp[1],tmp[0])
        ser.write(bytes(s,"utf-8"))

[tab26715]

Where would that python code be written? In led.py?

[joeybab3]

Do you have the rest of this? I would love to try implementing this a little better.

[ManuelLevi]

Unfortunately, I don't have that code anymore but I don't think you need much more than what I've posted here, have you tried it following the posts?

I don't have much time now, but if you have any problems I'll try to help as much as I can.

Good luck!

[artemanderson]

Hi Manuel, when I injected your snippet into the LedStripColorTester sketch, the
" current_led = Serial.parseInt();" line gives an error -
"error: 'current_led' was not declared in this scope"

I'm very new to working in Arduino, would you be able to explain what is needed to fix this?

[ManuelLevi]

You'll have to define all those variables before using them, like int current_led;.
https://www.arduino.cc/en/Reference/VariableDeclaration