Category Archives: Raspberry Pi Pico

Connecting the Adafruit Ultimate GPS to the Raspberry Pi Pico W

June 9, 2025 admin

In this video lesson we will connect the Adafruit Ultimate GPS to the Raspberry Pi Pico W, and will write a simple program to capture the data being sent by the GPS. In this lesson, we simply want to read and print the NMEA sentences coming off the GPS, and then in future lessons we will begin to parse the data, and turn the data into usable numbers. This is the schematic for connecting the GPS to your Raspberry Pi Pico W.

This schematic shows how to connect the Adafruit Ultimate GPS to the Raspberry Pi Pico W

Then this is the simple code we developed to allow reading the data coming from the GPS.

from machine import Pin,I2C,UART  #***************
import time

GPS = UART(1, baudrate=9600, tx=machine.Pin(8), rx=machine.Pin(9))
try:
    while True:
        if GPS.any():
            #myChar=GPS.read(1)
            myChar=GPS.read(1).decode('utf-8')
            print(myChar, end="") #Supress the line feed, so It continues to print across
except KeyboardInterrupt:
    print("\nStopping program... Cleaning up UART.")
    GPS.deinit()  # Properly release UART before exit
    time.sleep(1)  # Short pause to ensure clean shutdown
    print("Exited cleanly.")

from machine import Pin,I2C,UART #***************

import time

GPS = UART(1, baudrate=9600, tx=machine.Pin(8), rx=machine.Pin(9))

try:

while True:

if GPS.any():

#myChar=GPS.read(1)

myChar=GPS.read(1).decode('utf-8')

print(myChar, end="") #Supress the line feed, so It continues to print across

except KeyboardInterrupt:

print("\nStopping program... Cleaning up UART.")

GPS.deinit() # Properly release UART before exit

time.sleep(1) # Short pause to ensure clean shutdown

print("Exited cleanly.")

Raspberry Pi Pico, Tutorial

Powering Your Raspberry Pi Pico W from Battery for Portable Operation

May 25, 2025 admin

In this video lesson we discuss powering your Raspberry Pi Pico W projects from a battery, allowing portable operation of the project. Most all of our earlier lessons can be powered by battery, allowing the project to operate without being connected to the USB cable. In this lesson I discuss the important issues that must be considered when powering your project from battery, and particularly issues associated with powering your project from battery, but then needing to download the code. I want to explicitly explain how to do this in this lesson, so in future lessons when you see me with the battery connected to the project, you will know what I am doing.

To get started, I will demonstrate with this simple circuit, so go ahead and build this circuit:

Simple circuit to demonstrate a LED toggle

Then, we will be using this simple code:

from machine import Pin
import time
redPin=16
bluePin=17
buttonPin=19
# Initialize LED on GP16
redLED = Pin(redPin, Pin.OUT)
blueLED=Pin(bluePin,Pin.OUT)
# Initialize button on GP19 with internal pull-up resistor
button = Pin(buttonPin, Pin.IN, Pin.PULL_UP)
# Variable to track LED state
buttonState=1  # False = off, True = on
buttonStateOld=1
blueLED.on()

while True:
    # Read current button state
    buttonState = button.value()
    # Check for button press (LOW due to pull-up, button connects to ground)
    if buttonStateOld == 1 and buttonState == 0:
        # Button was pressed (falling edge)
        redLED.toggle()
        time.sleep(.2) #debounce the switch
    # Update last button state
    buttonStateOld=buttonState

from machine import Pin

import time

redPin=16

bluePin=17

buttonPin=19

# Initialize LED on GP16

redLED = Pin(redPin, Pin.OUT)

blueLED=Pin(bluePin,Pin.OUT)

# Initialize button on GP19 with internal pull-up resistor

button = Pin(buttonPin, Pin.IN, Pin.PULL_UP)

# Variable to track LED state

buttonState=1 # False = off, True = on

buttonStateOld=1

blueLED.on()

while True:

# Read current button state

buttonState = button.value()

# Check for button press (LOW due to pull-up, button connects to ground)

if buttonStateOld == 1 and buttonState == 0:

# Button was pressed (falling edge)

redLED.toggle()

time.sleep(.2) #debounce the switch

# Update last button state

buttonStateOld=buttonState

In the video, we will explain the ins and outs of now powering a project like the one above using a battery supply. Note for now though, that the wire from pin 36 to the bottom power rail establishes that rail as a 3.3 volt rail, defined by the Pi Pico.

Now, if we want to power the project remotely, that is, remove the USB cable and power from the battery, we will need to supply a suitable voltage both to the nonblinking LED (The Blue One) and the Pi Pico itself.

You can power the Pi Pico by applying a voltage to the VSYS pin, which is physical pin 39. The voltage should be between 1.8 and 5.5 volts. So, we can power the LED and the Pi Pico by connecting a suitable power supply. For our examples, I use the Sunfounder Breadvolt (AVAILABLE HERE).

However, when we connect the breadvolt to the breadboard, and we we intend to power the project by the Breadvolt, we need to adjust the wiring where instead of pin 36, we should connect pin 39 to the power rail. This is because in using the breadvolt as the power supply, it will define the voltage of the power rail, not the Pi Pico. The Pi Pico will be a USER of the rail, not the one who supplies voltage to it. So, to power the Pico, we need to connect pin 39 to the power rail instead of 36. So, in using the Breadvolt to power the project, we should use this circuit:

Notice that we now are connecting pin 39 to the Pi Pico

Now with this schematic, we can disconnect the USB, turn the breadvolt on, and power the project (Pi Pico and the Blue LED) from the breadvolt.

Now the question arises, how would we now download code to the project? The bottom line is, it is never a good idea to have two different voltages supplies connected to the rail, or for that matter connected together. So, the simple solution is, turn the breadvolt OFF, before reconnecting the USB cable. Then download the code. Then disconnect the USB cable, and then turn the breadvolt back on.

What you will see, when the breadvolt is turned off, and the USB cable is reconnected to the project, VSYS will act as an output pin, powering the blue LED. Vsys pin is connected to the USB supply by a diode. There is a small voltage drop across the diode, so the voltage at the VSYS will be around 4.8 volts.

Please watch the video as we will be giving more specific examples of how to make this work.

Raspberry Pi Pico

Getting Geared Up for the Ultimate GPS Tracker with Raspberry Pi Pico W

May 22, 2025 admin

Gearing Up for the Ultimate GPS Challenge

Guys in this class we will be building the Ultimate GPS Tracker. This will build on all you learned in our most excellent Raspberry Pi Pico W class, and now we will begin working on a real project. Hopefully most of the gear you will already have from the various kits you already have, but I give amazon links to the gear we will be using in the project. You Will Need:

Raspberry Pi Pico W: ORDER HERE
Adafruit Ultimate GPS: ORDER HERE
External Antenna (OPTIONAL): ORDER HERE
Button Battery For Quicker Fix: ORDER HERE
Soldering Iron: ORDER HERE
Solder Practice Components: ORDER HERE
Extra Solder: ORDER HERE
Safety Glasses: ORDER HERE
Breadvolt Power Supply (OPTIONAL): ORDER HERE
Charging Cable (If You Don’t Have): ORDER HERE
OLED SSD1306: (ORDER HERE)
Breadboard and Wires (If You Don’t Have): ORDER HERE

MicroPython, Raspberry Pi Pico

RFID Project to Lock and Unlock Control of Servo

May 20, 2025 admin

In this video lesson we explore a project where control access to a servo is activated by an RDID tag. In order to position the servo with the pushbuttons, the system must be unlocked by a RDID tag. When the system is locked, the LED is red, when the system is unlocked, the LED is green. When using the breadvolt, or any battery power supply on a breadboard project, do not turn the power supply on while the Raspberry Pi Pico is connected to USB, as you could generate voltage conflicts. It is an either or. If the USB is connected, the power supply should be OFF. Or if you are going to connect the USB, first turn off the power supply.

This schematic allows servo control to be granted via RFID tag

For your convenience, this is the code we developed below.

from mfrc522 import SimpleMFRC522
import time
import ujson
from machine import Pin, PWM
unlockTime = 5
decPin = 20
incPin = 21
servoPin=0
decBut=Pin(decPin,Pin.IN,Pin.PULL_UP)
incBut=Pin(incPin,Pin.IN,Pin.PULL_UP)

redPin=15
greenPin=14
bluePin=13
redLED=Pin(redPin,Pin.OUT)
greenLED=Pin(greenPin,Pin.OUT)
blueLED=Pin(bluePin,Pin.OUT)
redLED.on()
greenLED.off()
blueLED.off()

incButState=1
incButStateOld=1

decButState=1
decButStateOld=1

myServo=PWM(Pin(servoPin))
myServo.freq(50)
servoAngle=0

reader=SimpleMFRC522(spi_id=0,sck=18,miso=16,mosi=19,cs=17,rst=9)

try:
    f=open("/dict.json","r")
    servoDict=ujson.load(f)
    f.close()
except:
    myDict={}
    f=open('dict.json','w')
    ujson.dump(myDict,f)
    f.close()
def readRFID():
    global cardID,servoAngle
    print()
    print("System LOCKED")
    print("Reading . . . Please Place the Card")
    cardID,readText = reader.read()
    print()
    print("ID: ",cardID)
    try:
        f=open('/dict.json','r')
        servoDict = ujson.load(f)
        f.close()
        servoAngle=servoDict[cardID]
        print(servoAngle)
        moveServo()
    except:
        f=open('/dict.json','r')
        myDict=ujson.load(f)
        f.close()
        myDict[cardID]=servoAngle
        f = open('/dict.json','w')
        ujson.dump(myDict,f)
        f.close()
        moveServo()

def moveServo():
    writeVal = 6553/180*servoAngle + 1638
    myServo.duty_u16(int(writeVal))
    f=open('/dict.json','r')
    myDict =ujson.load(f)
    f.close()
    myDict[cardID]=servoAngle
    f=open('/dict.json','w')
    ujson.dump(myDict, f)
    f.close()
while True:
    redLED.on()
    greenLED.off()
    blueLED.off()
    readRFID()
    print("System Unlocked by Card: ",cardID)
    unlockStart= time.time()
    while time.time()-unlockStart<unlockTime:
        redLED.off()
        greenLED.on()
        incButState=incBut.value()
        decButState=decBut.value()
        if incButState==0 and incButStateOld==1:
            servoAngle=servoAngle + 10
            if servoAngle>180:
                servoAngle=180
            if servoAngle<0:
                servoAngle=0
            moveServo()
            unlockStart=time.time()
            time.sleep(.2)
        if decButState==0 and decButStateOld==1:
            servoAngle=servoAngle - 10
            if servoAngle>180:
                servoAngle=180
            if servoAngle<0:
                servoAngle=0
            moveServo()
            unlockStart=time.time()
            time.sleep(.2)
        incButStateOld=incButState
        decButStateOld=decButState

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from mfrc522 import SimpleMFRC522

import time

import ujson

from machine import Pin, PWM

unlockTime = 5

decPin = 20

incPin = 21

servoPin=0

decBut=Pin(decPin,Pin.IN,Pin.PULL_UP)

incBut=Pin(incPin,Pin.IN,Pin.PULL_UP)

redPin=15

greenPin=14

bluePin=13

redLED=Pin(redPin,Pin.OUT)

greenLED=Pin(greenPin,Pin.OUT)

blueLED=Pin(bluePin,Pin.OUT)

redLED.on()

greenLED.off()

blueLED.off()

incButState=1

incButStateOld=1

decButState=1

decButStateOld=1

myServo=PWM(Pin(servoPin))

myServo.freq(50)

servoAngle=0

reader=SimpleMFRC522(spi_id=0,sck=18,miso=16,mosi=19,cs=17,rst=9)

try:

f=open("/dict.json","r")

servoDict=ujson.load(f)

f.close()

except:

myDict={}

f=open('dict.json','w')

ujson.dump(myDict,f)

f.close()

def readRFID():

global cardID,servoAngle

print()

print("System LOCKED")

print("Reading . . . Please Place the Card")

cardID,readText = reader.read()

print()

print("ID: ",cardID)

try:

f=open('/dict.json','r')

servoDict = ujson.load(f)

f.close()

servoAngle=servoDict[cardID]

print(servoAngle)

moveServo()

except:

f=open('/dict.json','r')

myDict=ujson.load(f)

f.close()

myDict[cardID]=servoAngle

f = open('/dict.json','w')

ujson.dump(myDict,f)

f.close()

moveServo()

def moveServo():

writeVal = 6553/180*servoAngle + 1638

myServo.duty_u16(int(writeVal))

f=open('/dict.json','r')

myDict =ujson.load(f)

f.close()

myDict[cardID]=servoAngle

f=open('/dict.json','w')

ujson.dump(myDict, f)

f.close()

while True:

redLED.on()

greenLED.off()

blueLED.off()

readRFID()

print("System Unlocked by Card: ",cardID)

unlockStart= time.time()

while time.time()-unlockStart<unlockTime:

redLED.off()

greenLED.on()

incButState=incBut.value()

decButState=decBut.value()

if incButState==0 and incButStateOld==1:

servoAngle=servoAngle + 10

if servoAngle>180:

servoAngle=180

if servoAngle<0:

servoAngle=0

moveServo()

unlockStart=time.time()

time.sleep(.2)

if decButState==0 and decButStateOld==1:

servoAngle=servoAngle - 10

if servoAngle>180:

servoAngle=180

if servoAngle<0:

servoAngle=0

moveServo()

unlockStart=time.time()

time.sleep(.2)

incButStateOld=incButState

decButStateOld=decButState

MicroPython, Raspberry Pi Pico

RFID Lock and Unlock Demonstration Project Raspberry Pi Pico W

May 13, 2025 admin

In this video lesson we explore using an RFID-RC522 and an RFID tag to lock and unlock our raspberry pi project. This demonstration will include an RGB LED which remains red while the system is locked, and then turns green when the system is unlocked by the RFID tag. Absence of user input, the system will lock again after 5 seconds. The following is the circuit diagram for the project:

Schematic for Raspberry Pi Pico W and RFID module, with LED and Push Buttons

When using the breadvolt, or any battery power supply on a breadboard project, do not turn the power supply on while the Raspberry Pi Pico is connected to USB, as you could generate voltage conflicts. It is an either or. If the USB is connected, the power supply should be OFF. Or if you are going to connect the USB, first turn off the power supply.

For your convenience, the code for the project is included below:

from mfrc522 import SimpleMFRC522
import time
from machine import Pin, PWM
unlockTime = 5
decPin = 20
incPin = 21
decBut=Pin(decPin,Pin.IN,Pin.PULL_UP)
incBut=Pin(incPin,Pin.IN,Pin.PULL_UP)

redPin=15
greenPin=14
bluePin=13
redLED=Pin(redPin,Pin.OUT)
greenLED=Pin(greenPin,Pin.OUT)
blueLED=Pin(bluePin,Pin.OUT)
redLED.on()
greenLED.off()
blueLED.off()

incButState=1
incButStateOld=1

decButState=1
decButStateOld=1

butCount = 0

reader=SimpleMFRC522(spi_id=0,sck=18,miso=16,mosi=19,cs=17,rst=9)

def readRFID():
    global cardID
    print()
    print("System LOCKED")
    print("Reading . . . Please Place the Card")
    cardID,readText = reader.read()
    print()
    print("ID: ",cardID)
while True:
    redLED.on()
    greenLED.off()
    blueLED.off()
    readRFID()
    print("System Unlocked by Card: ",cardID)
    unlockStart= time.time()
    while time.time()-unlockStart<unlockTime:
        redLED.off()
        greenLED.on()
        incButState=incBut.value()
        decButState=decBut.value()
        if incButState==0 and incButStateOld==1:
            butCount=butCount+1
            print("Button Count: ",butCount)
            unlockStart=time.time()
            time.sleep(.2)
        if decButState==0 and decButStateOld==1:
            butCount=butCount-1
            print("Button Count: ",butCount)
            unlockStart=time.time()
            time.sleep(.2)
        incButStateOld=incButState
        decButStateOld=decButState

from mfrc522 import SimpleMFRC522

import time

from machine import Pin, PWM

unlockTime = 5

decPin = 20

incPin = 21

decBut=Pin(decPin,Pin.IN,Pin.PULL_UP)

incBut=Pin(incPin,Pin.IN,Pin.PULL_UP)

redPin=15

greenPin=14

bluePin=13

redLED=Pin(redPin,Pin.OUT)

greenLED=Pin(greenPin,Pin.OUT)

blueLED=Pin(bluePin,Pin.OUT)

redLED.on()

greenLED.off()

blueLED.off()

incButState=1

incButStateOld=1

decButState=1

decButStateOld=1

butCount = 0

reader=SimpleMFRC522(spi_id=0,sck=18,miso=16,mosi=19,cs=17,rst=9)

def readRFID():

global cardID

print()

print("System LOCKED")

print("Reading . . . Please Place the Card")

cardID,readText = reader.read()

print()

print("ID: ",cardID)

while True:

redLED.on()

greenLED.off()

blueLED.off()

readRFID()

print("System Unlocked by Card: ",cardID)

unlockStart= time.time()

while time.time()-unlockStart<unlockTime:

redLED.off()

greenLED.on()

incButState=incBut.value()

decButState=decBut.value()

if incButState==0 and incButStateOld==1:

butCount=butCount+1

print("Button Count: ",butCount)

unlockStart=time.time()

time.sleep(.2)

if decButState==0 and decButStateOld==1:

butCount=butCount-1

print("Button Count: ",butCount)

unlockStart=time.time()

time.sleep(.2)

incButStateOld=incButState

decButStateOld=decButState

Technology Tutorials

Category Archives: Raspberry Pi Pico

Connecting the Adafruit Ultimate GPS to the Raspberry Pi Pico W

Powering Your Raspberry Pi Pico W from Battery for Portable Operation

Getting Geared Up for the Ultimate GPS Tracker with Raspberry Pi Pico W

RFID Project to Lock and Unlock Control of Servo

RFID Lock and Unlock Demonstration Project Raspberry Pi Pico W

Making The World a Better Place One High Tech Project at a Time. Enjoy!