support controlling WS2812(-like) LEDs / stripes

[orangecms]

• I'm submitting a ...

  • bug report
  • feature request

• What is the current status?

This is not yet implemented afaik. There is a way to generate square waves, but that's about it so far.

• What is the expected behavior?

We'd need to wire this up here in the app. A an API and the UI allowing to add a number of LEDs in a row plus their type would be the the minimum; later on, we can add effects like rainbow etc..

• Other information ( Any research that you may have done which you think is the cause of problem )

The Python lib can already do this, on the SQ1 pin: I.WS2812B([[255,0,0]],'SQR1')

See also the NodeMCU firmware project providing a rich library for the ESP8266: https://github.com/nodemcu/nodemcu-firmware/blob/master/app/modules/ws2812.c

• Would you like to work on it?

[orangecms]

This works:

from PSL import sciencelab
from time import sleep

pslab = sciencelab.connect(port = "/dev/ttyUSB0")

r = [255,0,0] # red
g = [0,255,0] # green
b = [0,0,255] # blue

y = [255,255,0] # yellow
m = [255,0,255] # magenta
c = [0,255,255] # cyan

w = [200,200,200] # white

lights = [r, g, b, y, m, c, w, r,
          g, b, y, m, c, w, r, g,
         ]
#          b, y, m, c, w, r, g, b,
#          y, m, c, w, r, g]

while True:
    pslab.WS2812B(lights,'SQR1')
    lights = lights[1:] + lights [:1]
    sleep(0.5)

The additional LEDs after the first 16 are intentionally commented out. When I tried, I got some errors like the following:

unpack requires a buffer of 1 bytes
unpack requires a buffer of 1 bytes

The green LED indicating MCU activing was blinking somehow. It could be a bug in pslab-firmware.

Addendum: I used a USB charger for power supply and thus a different USB serial adapter to protect my laptop's USB ports while drawing much current. These LEDs can take up to 50mA each, so 30 of them, which I have on a strip, could draw 1.5A, which is quite a lot.