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MicroPython MY9221

A MicroPython library for 10 segment LED bar graph modules using the MY9221 LED driver.

For example, the Grove - LED Bar module

Examples

Copy the file to your device, using ampy, webrepl or compiling and deploying. eg.

$ ampy put my9221.py

Basic usage

from my9221 import MY9221
from machine import Pin
ledbar = MY9221(di=Pin(4), dcki=Pin(5))

# all LEDS on, full brightness
ledbar.level(10)

# four LEDS on, half brightness
ledbar.level(4, 0x0F)

# first and last LED on
ledbar.bits(0b1000000001)
ledbar.bits(0x201)
ledbar.bits(513)

# alternating LEDs
ledbar.bits(0b0101010101)
ledbar.bits(0b1010101010)

# fade out LEDs
buf = bytearray([0,1,3,7,15,31,63,127,255,255])
ledbar.bytes(buf)

# reverse orientation, first LED is green
ledbar.reverse(True)
ledbar.level(1)

# normal orientation, first LED is red
ledbar.reverse(False)
ledbar.level(1)

For more detailed examples, see my9221_test.py

Methods

Get or set the orientation. The red LED normally position 1, and when reversed is position 10. Once orientation has been set, all other methods respect the order.

reverse(val=None)

Illuminate a number of LEDs at a specific brightness. A value of 5 would light half of the display.

level(val, brightness=255)

Illuminate LEDs, one bit per LED at a specific brightness. Value can be 0-1023.

bits(val, brightness=255)

Use a bytearray, one byte per LED, to specify individual brightness for each LED.

bytes(buf)

Parts

• WeMos D1 Mini $3.50 USD
• Grove LED Bar $3.90 USD
• Grove Male Jumper Cable $2.90 USD

Connections

Links

• WeMos D1 Mini
• micropython.org
• MY9221 datasheet
• My Semi MY9221 product page
• BBC micro:bit version
• Adafruit Ampy
• micropython-my9221 on pypi

License

Licensed under the MIT License.