PICO Display Pack and 18B20 temp sensor

Support
1

I have a Pimoroni Display Pack that works just fine with my PICO.
I also have a 18B210 temp sensor that works just great with my PICO and displays to a 4x20 LCD.
But when I try to use the Display Pack, 18B20, and PICO together I get either a black screen or a
garbled mess on the screen.
My 18B20 data is coming in on pin 21(GP16) of the PICO. I have tried moving it to other pins on the PICO without success.

Any hints on this ?
Thanks.

2

Posting the code your using may help? If you put three ` before and after it will wrap it in code tags and maintain the indents etc. The pins used by the display are listed at the bottom of its product page.

600×552 113 KB

3

This works on my Pico Display using Thonny and Micropython.

# DS1820B with data on GP21
# Tony Goodew 10th April 2021
import picodisplay as display
import utime
width = display.get_width()
height = display.get_height()
display_buffer = bytearray(width * height * 2)
display.init(display_buffer)

# Ds18x20 Temperature sensor
# Data/Signal on GP0 + on 3v3 and GND to GND
import machine, onewire, ds18x20
 
ds_pin = machine.Pin(21)
ds_sensor = ds18x20.DS18X20(onewire.OneWire(ds_pin))
 
roms = ds_sensor.scan()
print('Found a ds18x20 device')
# Set the backlight to 50%
display.set_backlight(0.5)

def blk():
    display.set_pen(20,10,10)
    display.clear()
    display.update()
    
def title2(msg,r,g,b):
    display.set_pen(20,10,10)
    display.clear()
    display.update()
    display.set_pen(r,g,b)
    display.text(msg, 25, 25, 200, 4)
    display.update()
    utime.sleep(0.2)

display.set_pen(20,10,10)
display.clear()
display.update()
title2('Test DS18x20',0,0,255)
 
while True:
  ds_sensor.convert_temp()
  utime.sleep_ms(750)
  for rom in roms:
    print(ds_sensor.read_temp(rom))
    title2(str(ds_sensor.read_temp(rom)),0,0,255)
  utime.sleep(1)

I hope it works on yours. I put the data from the temperature sensor on GP21.

Let me know how you get on.

4

Thank you very much Tonygo2.
I had tried GP14, GP16, and GP22 with no success, but once I switched to GP21 it started working as it should.