SPI plug in :-)

Sven Meier · Tue Jan 28, 2014 9:39 pm

Hello,
I have seen that you have added a spi plugin

That is fantastic

i am currently developing a spi to dmx converter.
The first Prototype on the breadboard works great.

Have you any documentation about the spi protocol that you prefer use?

My prototype uses a serial eeprom like protocol, that allows to refresh a single channel without sending the data of all channels.

Sven Meier · Tue Jan 28, 2014 9:48 pm

In a frew I will have a final pcb.
If you want it , I can send you a sample.

Massimo Callegari · Tue Jan 28, 2014 10:07 pm

Hi Sven, well I can't say I'm a SPI expert.
I implemented the plugin to control LED strips with the WS2801 chip.
Since I'm not sure you can find the SPI interface on a PC, basically it is to be used with the Raspberry Pi for now.

I used just 3 signals: Data, clock and ground. That's it.
The Pi sends a train of bytes (each one is a DMX channel) up to the last LED I have to control.

If you have a PCB that makes possible to use it with a PC it would be fantastic ! (maybe USB ?)
Which use do you have in mind with the SPI protocol ?
I don't think QLC+ will use it as a generic output, but always to send DMX data

Sven Meier · Wed Jan 29, 2014 7:40 pm

USB to spi is very simple.
The most ftdi chips supports spi mode.

My project is to generate a dmx signal with the spi port of a cubieboard 3.

Do you remember my older post about the Qdesk ?

I have already ordered 20 motorised slider, many buttons , small tft displays... all of this would be controlled over a spi port.
In a few days I can post the schematics here

Sven Meier · Thu Jan 30, 2014 7:10 pm

One question

Do you need
a usb to WS2801 spi converter
or
a dmx to WS2801 spi converter
or
a Artnet to WS2801 spi converter

Massimo Callegari · Thu Jan 30, 2014 11:43 pm

Hi Sven, sure I remember your Qdesk project !
Right now I can use the Raspberry SPI to control some home made LED bars.
I would be glad to have a USB-SPI adapter to speed up the tests from my PC.

But would you really build one for me ? That would be too much of a kindness

Kathryn Rennie · Sun Feb 02, 2014 2:48 pm

I have had a lot of success using the SPI plugin OLA on a raspberry pi, then using Arcnet to talk to that. Drives pixel strips brilliantly.

Massimo Callegari · Sun Feb 02, 2014 3:16 pm

I've had success too on the Rpi, but without OLA

With the next version it will possible to use QLC+ even as an ArtNet to SPI converter

Sven Meier · Mon Feb 03, 2014 9:05 am

Hello Massimo, sorry for my late answer.

I am using the "Bus Pirate" to emulate a spi bus on my normal pc.

Link: http://dangerousprototypes.com/docs/Bus_Pirate

Br

Sven Meier

Sven Meier · Wed Feb 05, 2014 8:23 am

Artnet to spi is a great idea.

But I think a raspberry pi is oversized.

A small atxmega32a4 with a wiznet W5200 Ethernet chip is enough.

If some people have interest, I can put this on my todo list.

DJefke · Wed Feb 05, 2014 10:38 am

Something like this? https://github.com/bobo1on1/loc_controller/wiki