pixie_spi_test.py

# Pixie driver test abusing SPI bus for clean data transfer at any speed
# If this works, let me know so I can simplify usage!
# Currently it sends a raw byte array below to render images to connected
# Pixies, flashing between a PIX_SMILE icon and a solid color at a visible rate.

# -------------------------------------------------------------------------
# SPI must be enabled using "sudo raspi-config" under "Interfacing Options"
# -------------------------------------------------------------------------

import spidev
import time
spi = spidev.SpiDev()
spi.open(0,0)

# SPI HOOKUP:

#   -----------------+
#                    |
#    PIX_VCC     X   |
#          X     X   |
#          X     PIX_GND
#          X     X   |
#          X     X   |
#          X     X   |
#          X     X   |
#          X     X   |
#          X     X   |
#    PIX_DAT     X   |
#          X     X   |
#    PIX_CLK     X   |
#          X     X   |
#          X     X   |
#          X     X   |
#          X     X   |
#          X     X   |
#          X     X   |
#          X     X   |
#          X     X   |
#                    |

# SPI Settings
spi.max_speed_hz = 10000 # increase or decrease speed if issues occur
spi.mode = 0b01 # clock polarity and phase
spi.no_cs = True # No CS pin needed

while True:
	# Smiles
	bytes = [
		# Left display
		0,255,0, # max brightness
		16,38,32,38,16, # PIX_SMILE icon

		# Right display
		0,255,0, # max brightness
		16,38,32,38,16  # PIX_SMILE icon
	]

	spi.writebytes(bytes)
	time.sleep(0.05)

	# Solid
	bytes = [
		# Left display
		0,255,0, # max brightness
		127,127,127,127,127, # Solid color

		# Right display
		0,255,0, # max brightness
		127,127,127,127,127  # Solid color
	]

	spi.writebytes(bytes)
	time.sleep(0.05)