Driver for WS2812

[nui_de]

Hi Oliv'

just wanted to ask if you already made any progress

[Oliv']

just wanted to ask if you already made any progress

Hello !
No I didn't because I do not need a lot of leds, for now.
So I did not tried to improve speed, and I think that the most efficient way is to activate DMA.

[danicampora]

DMA will come, but we need the asynchronous API as well. DMA by itself won't save anytime if you still have to wait for the transfer to complete before moving on.

[Oliv']

DMA will come, but we need the asynchronous API as well. DMA by itself won't save anytime if you still have to wait for the transfer to complete before moving on.

Yes asynchronous is mandatory, I thought it was included as for the PyBoard.
By the way it is good to know, thanks

[danicampora]

The pyboard doesn't have an asynchronous API yet...

[Oliv']

The pyboard doesn't have an asynchronous API yet...

My bad !
I have misread this post, sorry !

[nui_de]

Hi Daniel,

I only wanted to report two obvious bugs in your source:
https://github.com/danicampora/wipy/blo ... /ws2812.py

First, please look at the SPI values: (corrected version)

Code: Select all

    # values to put inside the SPI register for each bit of color
    bits = (bytearray((0xE0, 0xE0)), bytearray((0xE0, 0xFC)),
            bytearray((0xFC, 0xE0)), bytearray((0xFC, 0xFC)))

You have to interchange bits[1] and bits[2]

Second thing I found in function 'update' it should be:

Code: Select all

for bit in range (0, 8, 2):

else the two LSB get never set.

Now I have really smooth color fading and brightness control !
This also affects the Library by Oliv' since it uses the same bytearray