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Using an OLED displays

Because the Huzzah32 is in the Adafruit Feather form factor, you can plug in a Feather OLED display and use it with MicroPython (or Arduino). In this example, we see the Adafruit FeatherWing OLED 128x32 display. You can also use the 128x64 pixel version with these examples (adjusting the dimensions in the setup step).

I2C Connection

The display connects to the Huzzah32 by I2C pins: scl Pin(22), sda Pin(23)

SSD1306 OLED library

These examples depend on a MicroPyhon module (ssd1306.py) for the display which can be found here:

https://github.com/micropython/micropython/tree/master/drivers/display

You must put the ssd1306.py file on the Huzzah32 for the following code to work

OLED code Example 1 - Display text and line

oled_simple.py

import time
import machine
import ssd1306 # https://github.com/micropython/micropython/tree/master/drivers/display

# set up I2C
i2c = machine.I2C(scl=machine.Pin(22), sda=machine.Pin(23))

# the ssd1306 module uses framebuf from MicroPyhon
# https://docs.micropython.org/en/latest/library/framebuf.html?highlight=framebuf
# for setting the "color" of elements in the display:
# 0 = black, 1 = white
# create the oled object with the 128x32 dimesions of the display at I2C address 0x3c
oled = ssd1306.SSD1306_I2C(128, 32, i2c, 0x3c)

oled.fill(0) # wipe the display with black
oled.text('Hello World!', 0, 0) # put some text on the screen at position 0,0, default to white
oled.hline(0, 10, 128, 1) # create a horizontal line of width 128, starting at position 0,10, with color white
oled.show() # show what's been written to the display

OLED Code Example 2 - Show ip address

oled_showip.py

import time
import machine
import network
import ssd1306 # https://github.com/micropython/micropython/tree/master/drivers/display

# set up I2C
i2c = machine.I2C(scl=machine.Pin(22), sda=machine.Pin(23))

# the ssd1306 module uses framebuf from MicroPyhon
# https://docs.micropython.org/en/latest/library/framebuf.html?highlight=framebuf
# for setting the "color" of elements in the display:
# 0 = black, 1 = white
# create the oled object with the 128x32 dimesions of the display at I2C address 0x3c
oled = ssd1306.SSD1306_I2C(128, 32, i2c, 0x3c)

sta_if = network.WLAN(network.STA_IF)
ipaddress = sta_if.ifconfig()[0] # assumes device is already connected to WiFi

oled.fill(1) # wipe the display with white
oled.text('IP='+ipaddress, 0, 0,0) # put ip address on the screen at position 0,0, white
oled.show() # show what's been written to the display

OLED Code Example 3 - Show ADC value graphically

oled_analog_read.py

import time
import machine
import network
import ssd1306 # https://github.com/micropython/micropython/tree/master/drivers/display

# set up I2C
i2c = machine.I2C(scl=machine.Pin(22), sda=machine.Pin(23))

# the ssd1306 module uses framebuf from MicroPyhon
# https://docs.micropython.org/en/latest/library/framebuf.html?highlight=framebuf
# for setting the "color" of elements in the display:
# 0 = black, 1 = white
# create the oled object with the 128x32 dimesions of the display at I2C address 0x3c
oled = ssd1306.SSD1306_I2C(128, 32, i2c, 0x3c)

# analog to digital input
# https://docs.micropython.org/en/latest/esp32/quickref.html#adc-analog-to-digital-conversion
adc = machine.ADC(machine.Pin(34)) # A2
adc.atten(machine.ADC.ATTN_11DB) # set up range for max input voltage of 3.6V
adc.width(machine.ADC.WIDTH_12BIT) # values from 0-4095

while True:
  value = adc.read()
  oled.fill(0)
  oled.text('value = ' + str(value), 0, 0)
  value = int(value * 128/4096) # scale to the width of the display
  oled.hline(0,10, value, 1) # draw a line with a width of the ADC read
  oled.show()
  time.sleep_ms(200)