I have a string of WS2801 LEDs (the type most often used with an Arduino or Raspberry Pi over SPI), as well as an evaluation kit/breakout board for USB-to-SPI-master (MCP2210).
However, I am more of a software guy and don't normally deal with hardware and electronics, so I'm having some issues actually getting the LEDs to work at all.
My setup is as follows-
- LED strand connected to a 5v 2A wall power supply
- Data wire connected to MOSI on MCP2210
- Clock wire connected to CLK on MCP2210
- MCP2210 connected to a Windows PC running the driver software
The issue is, with the above setup, the first LED on the strand seems to cycle through all of the colors continuously, without me sending any data. With the ground wire (spliced off the strand) connected to GND on the MCP2210, there is no cycling but the first LED remains lit a solid color (I'm assuming this indicates that no data is being sent to the strand, since it's capable of staying lit without further input).
So, my first question is-- should the ground be connected to both the strand and the MCP2210 module?
If not, what could be the cause of the cycling colors and how can it be prevented? I'm assuming it may also be some sort of issue with the data rate or clock, since it's cycling at a fairly constant rate...