As a part of my PoC project, I'm using single 5050 LED made by Adafruit. I wired it like this (LED - RPi):

  • DI (Data Input) - SPI0 MOSI
  • CI (Clock Input) - SPI0 SCLK
  • GND (Ground) - GND
  • VCC (5V) - 5V PWR

SPI is, as far as I'm concerned, is enabled - I've done it using raspi-config and also added required line in /boot/config.txt manually (I'm talking bout param=spi=on)

Output of lsmod | grep spi* command:

spidev                 16384  0
spi_bcm2835            16384  0

And ls -la /dev/spi*:

crw-rw---- 1 root spi 153, 0 Jul 29 19:17 /dev/spidev0.0
crw-rw---- 1 root spi 153, 1 Jul 29 19:17 /dev/spidev0.1

To try out my setup, I've launched python interpreter and wrote:

import spidev
spi = spidev.SpiDev(), 1)
resp = spi.xfer([0x00, 0x00, 0x00, 0x00])
resp = spi.xfer([0xFF, 0xFF, 0xFF, 0xFF])

And nothing happened. What's important, I want to achieve my goal using Python. SpiDev module was installed at the time of the trials. For now, I'm only interested in simple blink, after this is reached, I can go further with modulation or frequency settings.

At best you may "SEE" MOSI signal AKA "chip select" to change state when SPI device is "selected". You are "looking at " default speed of probably 100kHz which is hardly observable by human eye. You MAY be able to slow down the SPI data transfer by programming for minimal clock speed.

  • I've tried changing spi speed by spi.max_speed_hz = 1, but still no luck, I guess that's not the cause. – PotatoBox Aug 8 at 16:04
  • I just realized I told you to monitor wrong SPI signal. Put LED with limiting resistor on SS0 / CS0 chip select pin. Depending on configuration - it will "go low" (default) when you SPI port is selected. For better results put you SPI "transfer" code in a loop. Single flash is easy to miss. – Jan Hus Aug 9 at 13:37

you are opened the wrong port.,0) instead of,1),1) means you are send data to SPI1 not SPI0.

Because you are send the data for wrong pin. That's why nothing happened.

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