Tag: Project

The Pico has internal pull up /down circuits inside it.

I have made this simple circuit for demonstration.

Button could be connected in two ways.

1. Internal Pull Up/Down
2. External Pull UP/Down

In the schematic i connected a button to GP22 using a external pull up of resistor 10k. I also used a capacitor in parallel with the button to debounce the button externally.

Using a external pull-up resistor can also help to protect the GPIO pin from damage due to excessive current flow. Without a pull-up resistor, a short circuit or other electrical fault in the switch or button could potentially allow a large current to flow through the GPIO pin, damaging it or the microcontroller itself.

Sample Code

import machine

# Set up the button on GPIO22 with external pull-up resistor
button = machine.Pin(22, machine.Pin.IN, machine.Pin.PULL_UP)

# Set up the LED on GPIO4
led = machine.Pin(4, machine.Pin.OUT)

# Loop forever
while True:
    # Read the current button value
    curr_button = button.value()

    # If the button is pressed, turn on the LED
    if curr_button == 0:
        led.value(1)
    # Otherwise, turn off the LED
    else:
        led.value(0)

The internal temperature sensor of RP2040 is read using micropython. The Thonny IDE is used in Windows environment.

The temperature sensor is connected to Channel number 4 of the ADC.

But since this is a rather small implementation using Thonny IDE, it does most of the interfacing related code in the background.

Code

import machine
import time

"""
Function Name: Read internal temperature sensor
Description: This function reads the internal temperature sensor of RP2040 chip.
             The temperature sensor measures the Vbe voltage of a biased bipolar diode,
             connected to the fifth ADC channel (AINSEL=4).
"""
def read_internal_temperature_sensor():
    tsi = machine.ADC(machine.ADC.CORE_TEMP)
    temp = tsi.read_u16() * (3.3 / (65535))
    temp = 27 - (temp - 0.706)/0.001721
    return temp

while True:
    #reads the temprature and prints it
    print("Temperature: ", read_internal_temperature_sensor())
    #Create a dealy of 1 second
    time.sleep(1)

First you have to install micropython on your raspberry pi pico board.
Follow the steps shown in the video.

To blink the onboard LED you can follow these steps:

1. Connect your Raspberry Pi Pico to your Windows computer using a micro USB cable.
2. Open Thonny IDE on your Windows computer.
3. Click on the “File” menu and select “New”.
4. In the new window, enter the following code:

import machine
import time

led_onboard = machine.Pin(25, machine.Pin.OUT)

while True:
    led_onboard.toggle()
    time.sleep(1)

5. Save the file with a meaningful name and the “.py” extension.
6. Click on the “Run” menu and select “Run current script” or press the “F5” key.
7. Thonny IDE will run the code and the onboard LED of Raspberry Pi Pico will start blinking at a frequency of 1 second.

That’s it! You have successfully blinked the onboard LED of Raspberry Pi Pico using Thonny IDE on Windows.