Published April 7, 2022 © GPL3+

Temperature Reading with RPi Pico & MicroPython

New to embedded programming? Use MicroPython to read and display temperature and humidity on an LCD. No soldering or breadboard is needed.

BeginnerFull instructions provided1 hour2,789

Temperature Reading with RPi Pico & MicroPython

Things used in this project

Hardware components

Raspberry Pi Pico

Seeed Studio Grove Starter Kit for Raspberry Pi Pico

Software apps and online services

Thonny

Story

Is the room uncomfortable because of the temperature or the humidity?

Introduction

This project will show you how to program a microcontroller to get temperature and humidity readings and display those on an LCD.

You will utilize the Raspberry Pi Pico for this. It's a relatively new microcontroller development board that supports programming in Arduino as well as using C/C++. It also had support for MicroPython, which is good for those coming from a software development background.

The Components

You will need the Grove Shield as well as the temperature and humidity sensor, and the LCD from the Grove Starter Kit. You will also need two Grove connectors. Finally, you will need your Pico board and a USB cable.

The components: Grove cables, LCD, Base Shield, Temperature Sensor, and Pico

The Assembly

Follow the steps below to assemble your components.

Insert the Raspberry Pico Pico into the Grove Shield, paying attention so that the USB port aligns with the USB print on the Grove Shield.
Connect a Grove cable into port D18 on the shield, then connect the other end to the temperature and humidity sensor.
Connect another Grove cable to port I2C1 on the Grove shield, and then connect the other end to the LCD.

The assembled components.

MicroPython

Follow the steps below.

Insert one end of the USB cable into your computer.
Hold the Bootsel button on the Pico down with one hand.
With the other hand, insert the other end of the USB cable into the Pico.
Release the Bootsel button.
Go to your computer. A drive will appear there. Open the drive.
Double-click the HTML file in the drive to open it.
Scroll down the page to the Microcontrollers section.
Click on the MicroPython name.
Scroll down the page to the section titled Drag-and-Drop MicroPython.
Click on the highlighted section to download the UF2 file.
Wait for the download to complete.
Drag this file back to the root of the Pico.
The Pico will disconnect from your computer and reboot.

The IDE

You will need the Thonny IDE, which you can download from here. Install the software and start it up, then follow the steps below:

Go to the bottom of the Thonny IDE and change the Python interpreter to MicroPython.
Save the code, which is also available here, into the code editor.
Save the code as main.py on the Pico.
Download a zip containing the required libraries from Seeed Studios here.
Unzip the archive.
From Thonny, go to the File menu and choose Open.
Choose This Computer.
Browse to the unzipped archive and choose the file lcd1602.py
Go to the File menu and choose Save As.
Save it as lcd1602.py on the Pico.
Close the file.
From Thonny, go to the File menu and choose Open.
Choose This Computer.
Browse to the unzipped archive and choose the file dht11.py
Go to the File menu and choose Save As.
Save it as dht11.py on the Pico.
Close the file.
You should now be back on the file named main.py.
From the Thonny toolbar, click on Run.

The script will now run. You should see the output at the bottom of the editor, as well as on the LCD Screen.

1 / 6 • The steps

Watch a Video

A video step-by-step is available on YouTube.

MicroPython Code for Temperature Sensor and LCD Screen

#
# Weather Station. Requires:
# * Grove Shield, 
# * Temperature & Humidity Sensor,  
# * LCD
#

import utime
from lcd1602 import LCD1602
from dht11 import *
from machine import Pin, I2C
from time import sleep
 

dht2 = DHT(18) #temperature and humidity sensor connect to D18 port
i2c = I2C(1, scl=Pin(7), sda=Pin(6), freq=400000) # connect I2C
d = LCD1602(i2c, 2, 16) # connect the LCD
 
while True:  
 
    t,h = dht2.readTempHumid() # temp:  humid:
    
    d.clear() # clear the LCD so old text isn't visible
    d.print('T: {} C'.format(t))
    d.setCursor(0,1) # go to line 2 of the LCD
    d.print('H: {} %'.format(h))
    print('T: {}'.format(t)) # debug
    print('H: {}'.format(h)) # debug
    utime.sleep(5) # wait 5 seconds

Credits

Robert John

3 projects • 10 followers

Data Team lead by day, community and hardware builder at night. Arm Innovator, Edge Impulse Expert, Google Dev Expert.

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Temperature Reading with RPi Pico & MicroPython

Temperature Reading with RPi Pico & MicroPython

Things used in this project

Hardware components

Software apps and online services

Story

Introduction

The Components

The Assembly

MicroPython

The IDE

Watch a Video

Code

MicroPython Code for Temperature Sensor and LCD Screen

Credits

Robert John

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