The Raspberry Pi Pico Review - $4 ARM Microcontroller

here's the too long didn't watch the raspberry pi pico is a new four us dollar microcontroller board with a custom new dual core 133 megahertz arm cortex m0 plus microprocessor two megabytes of built-in flash memory 26 gpa opens an assortment of spi i2c uart adc pwm and pio channels it also has a few other party tricks like edge castellations that make it easier to solder the pico to other boards and if you have no clue what any of that means don't worry i only know about two percent of the world of microcontrollers myself the pico is powered by this new rp2040 chip that sits right in the middle and it's a brand new raspberry pi built arm processor and the best thing about this processor is the insanely detailed data sheet available on the pico website that steps through every single bit of the chip's architecture if you want to skip ahead to just the pi pico review or any other part of this video use the chapters in the description or the play bar now let's dive right in when i got the pico in the mail i asked redshirt jeff if he had any ideas for a project but i had to nix that idea pretty quickly when he explained his idea for a remote control blowtorch so i got to thinking and i remembered that a few years ago i was concerned about how cold one of my kids bedrooms got in the winter since small children have a higher risk of death from sids if the ambient room temperature is too low or too high i was right to worry the recommended ambient temperature for kids rooms is between 68 and 72 degrees oh and i'm guessing if you're not from the usa you might be wondering why we're cooking our children don't worry we're not that's degrees fahrenheit are crazy murica units in the rest of the world the safe range is 20 to 22.2 degrees celsius anyways back then i built a complicated set of raspberry pi temperature monitoring stations i open sourced my code and i even blogged about it on opensource.com fast forward a few years later and well yet again [Music] we had a baby so i'm going to make sure my new baby girl stays a safe temperature using a raspberry pie pico but before i get into my little project i'll give a quick rundown on the specs and why the pico is a great value for four dollars when i first saw the pico i thought immediately of the teensy lc that's almost identical in size and also has an arm m0 processor but it's three times slower with a single core and a lot less flash storage the going rate for a teen clc is eight dollars twice the pico there's also the esp32 but a full package like the pico offers costs 10 to 20 dollars obviously wireless capabilities on the esp32 aren't present on the pico so you have to discount that in the price but it is a lot less money if you don't need wi-fi or bluetooth finally there's also the pro micro but it offers a different set of trade-offs and a way slower clock speed than the pico and it also costs 10 or more most places online anyways here are the specs of the raspberry pi pico it has an rp2040 microcontroller with two megabytes of flash storage the processor runs up to 133 megahertz and is based around a dual core cortex m0 plus design the processor also has 264 kilobytes of sram the processor has two uart two i squared c 2 spi and up to 16 pwm channels the processor includes a timer with 4 alarms and a real-time counter as well as dual programmable i o peripherals it uses a micro usb port for power and data and for programming the flash 40 pins are both through-hole and casculated for mounting flexibility there are 26 3.3 volt gpio pins 23 of the gpio pins are digital only and 3 are adc capable it has a 3 pin arm serial wire debug port and finally it can be powered via micro usb or a dedicated power supplier battery the easiest way to get started with the pico is to hold down the boot cell button on it while you plug it into a computer it'll be mounted as a mass storage device and it even includes a handy link right on the board to the getting started guide to program the pico with micro python you can use the thony python ide that's already built into raspberry pi os or you can install it on any mac windows or linux pc before you can run micro python code though you need to follow the instructions on the pico getting started guide to download a uf2 file that will install micro python on the pico and reboot it after that the pico will automatically run whatever's stored in main.pi on the picos file system when it boots up there's an entire book called get started with micropython on raspberry pi pico available through the pico website and i highly recommend it now that we know a bit about the pico itself and how to program it i need to explain when i'd use a microcontroller instead of a full computer like a raspberry pi with its gpio pins for me the main reason is usually power consumption i've done a lot of power testing for my raspberry pi projects typically i measure power consumption in amps and watts though there are a few pi models like the model a plus and zero that sip only a few hundred milliamps when running at five volts which translates into 1 or 2 watts well when we talk about microcontrollers like the rp2040 on the pico power efficiency is on a different planet in sleep or dormant mode the pico consumes less than 2 milliamps or 6 milliwatts that's .006 watts and even when it's running full tilt doing graphics rendering it uses less than 100 milliamps or 0.33 watts so if you program it efficiently you can run the pico off a small rechargeable battery like this one for days or even weeks the pico data sheet even has a suggested diagram if you want to wire up your own battery charging circuit you might still be wondering what you can do with a microcontroller well the pico is fast enough that it can actually output video through vga or dvi it can process audio it can control relays for things like irrigation systems and it can even assist in flying spaceships for tv shows that's right the razer crest model from the mandalorian was controlled using a custom controller built with a teensy usb board which is very similar to the pico though it's a little bit faster check out how that worked in the tested video linked in the card up above in that video ilm engineers explained how they built the custom motion control rig for controlling the spaceship model alright so i have a pipe eco and i'm about 100 times less experienced than those ilm engineers but i have a simple goal make it easy to tell if the room temperature is safe for baby so how do i do it well here's the idea i have going into this project the final form might be a little bit different but what i'm thinking is i'll have the pipe eco a temperature sensor and three leds red green and blue i'll write some python that does the following it measures the temperature every five seconds if the temperature is in the safe range 20 to 22.2 degrees celsius turn off the red and blue leds and turn on the green led if the temperature is too high which is more than 22.2 degrees celsius turn off the blue and green leds and turn on the red led and if the temperature is too low less than 20 degrees celsius turn off the red and green leds and turn on the blue led and you're thinking jeff that sounds like a really simple device why not try something a little harder well let me tell you something about designing hardware things never work the way you think and the simpler the design the fewer the surprises and i only have a few spare hours when our new baby is sleeping and i'm not so simpler equals more likely to actually make it in this video so let's speed up time for a build montage first up i had to make sure i could get my own micro python code working so i used my kids pi 400 and got the little built-in led on gpio pin 25 to turn on and off with code after that i got one led wired up to gpio pin 15 simply because that was the closest pin to where i put the led on my breadboard once i could light up those two leds i wired everything else up including a little ds-18b20 temperature sensor with a pull-up resistor for parasite power then i went to town coding i started the script by flashing all the leds for one second then i wrote a loop that would check the temperature every five seconds and set the correct led corresponding to the current temperature and in the end i found that the early beta version of micro python i was using didn't have one wire support built in so it was a little rough getting the ds18b20 sensor working luckily though the pico has a built-in temperature sensor inside the rp2040 chip now it's not quite as accurate but it seemed to be within plus or minus one degree celsius of my other thermometers so i finished the build tested it and generated this little fritzing breadboard diagram in case you want to replicate my program oh and like everything else i do i open sourced all my work so you can run the same software if you want so anyways here it is the first beta version of jeff gearling's safe baby room temperature monitor no patent spending if i warm up the picot to more than 22.2 degrees celsius the red led comes on and if i cool it down to less than 20 degrees celsius in this case using one of my kids funky little ice packs the blue led comes on it was dead simple to get this working and with a little polish i could install everything on a custom pcb pretty easily and if i ever crack open the box to my new ender 3d printer maybe i could even print a snazzy case for it anyways check out my first pico project on github and maybe use it as inspiration to build something on your own to wrap things up though one of the things i don't like about the picos design is the lack of pin labels on the top of the device they're all labeled nicely on the bottom but only pins 1 2 and 39 are labeled on the top there's no way to see which pin is which when i have it plugged into a breadboard it would be nice if the pie foundation could silk screen labels on top somehow maybe like the teensy does it with little angled labels other than that there's not much wrong with the pico for its price i mean having two cores may be nice for some projects but most of my own work wouldn't benefit from dealing with the complexity of multiple threads and software but that's not really a bad thing all in all i think the pi foundation has a winner with their new four dollar microcontroller and i can't wait to see what other people come out with based on the rp2040 chip i just hope the pi foundation can keep up with demand it would be really sad if they're hard to find months after launch like what's happened with the compute module 4. one other thing i want to see is a full getting started kit with lots of different components like you can find for the arduino i'm sure some companies will be putting these together so i'll keep my eyes open anyways thanks for watching and until next time i'm jeff gearling to getting started oh man i didn't know sram made you burp micro python i oh no i might be a robot is that another gray hair before you can run micro python code no kodo after that the pie and it can even assist this is like take 27 i'm not even joking like you can find for our arduino arduino arduino

Channel: Jeff Geerling

Views: 281,968

Keywords: raspberry pi, pico, rpi, microcontroller, arduino, maker, craft, hobby, electronics, wires, temperature, safety, project, board, electric, leds, led, thonny, python, micropython, os, ide, onewire, ds18b20, circuitpython, review, launch, measure, probe, rp2040, specs, specifications, how to, guide, programming, tutorial, montage, red shirt jeff

Id: dUCgYXF01Do

Length: 11min 18sec (678 seconds)

Published: Wed Jan 20 2021

Reddit Comments

[u/leprasmurf]

I use Jeff's ansible roles all the time. Great work.

[u/patniemeyer]

What I look forward to is using the Pi Pico as a low power controller to wake up and shut down a regular raspi for long term use on battery... I hope this was thought out well when they designed this.

[u/Hrnek_Bezucha]

Last time I noticed, Jeff was banned from posting here for whatever reason. He's one of the greatest RPi voices out there.

[u/UnicornJoe42]

Something ask me that you can't use Python on it =(