Microcontrollers Arduino Uno, Raspberry Pi Pico and BBC Micro:bit Compete in Ice Challenge.

The fact that microcontrollers like Arduino UNO, raspberry Pi Pico or BBC Micro:bit can work in range of temperature of -40℃ up to 85℃ are a bit extreme to me because I live in a country which the temperature cannot be less than 19℃ except you turn on the air conditioner. The weather in Malaysia is almost constant through out the year which can be range of 19℃ up to 38℃ .

Fun Fact: these microcontrollers can work in extreme temperature.(Thermal performance) according to datasheet respectively.

Uno: -40℃ until 125℃ link here to the pdf

Pi Pico: -40℃ until 85℃ link here to the pdf

Micro:bit: -40℃ until 105℃ ( https://tech.microbit.org/hardware/#temperature-sensing)

So I went to investigate this fact and making a little experiment to record the temperature of the microcontroller in box of ice and a bit of popsicles.

This experiment does not need extra temperature sensor because each of the microcontroller had one internal temperature sensor. You just need a coding to pull the sensor reading. For arduino UNO you need to buy one microSD card module to keep/store the data because UNO do not have the capability to store the data.

You can simply put inside the cold fridge or freezer(deep) but its hard for me to record it using my laptop's camera.

I just use one plastic box to put all three microcontrollers inside with the ice bags

Microcontrollers:

• 1- Arduino UNO board, jumpers, MicroSD card, MicroSD module, USB Type B - Type A , 9V battery, 9V battery snap - Male Jack 2.1mm
• 2- Raspberry Pi Pico board - 2 x AA batteries, 2xAA battery holder with 1P dupont female connector, USB Type Micro-B - Type A
• 3- BBC Micro:bit board V2 only, 2 x AA batteries, 2xAA battery holder with JST connector, USB Type Micro-B - Type A

Others:

• 4- Plastic sheet(thick) to put the microcontrollers for the protection against the water from the ice.
• 5- Plastic Box (transparent which I can see through if the microcontroller works or not.
• 6- Ice bags and some ice cream/popsicles (for fun!)
• 7- Timer( smartphone or watch)
• 8- Camera(to record the timelapse)
• 9- Laptop/PC for coding

Arduino UNO - open the arduino IDE . According to the datasheet here(link here to the pdf) on page 216, and from the reference of the code www.engineersgallery.com/arduino-internal-temperature-sensor , I make a new code to do the connection to microSD card module. Uno do not have the capability to store the data which we will write the temperature. So we have to use the microSD card to make it works.

Get the code here or you can download below.

Pi Pico - According to the datasheet here on page 565 (link here to the pdf) and you can code it using Thonny IDE. If you are a new to pico , you can check the tutorial here .

BBC Micro:bit - Open the https://makecode.microbit.org . Use the blocks. Click the extension and choose the datalogger. Use the set timestamp for SECONDS at the on start block. For forever block, use input (temperature ℃) and drag into log data block inside the value. For column, write down the temperature. Do the basic block pause(10,000) = 10 seconds delay and paste it below the block.

Or you can view my block here

Pico and Micro:bit can be plug into the external power using the two AA batteries.

Only the Uno we have to wiring to microSD card module.

Put all the ice bags and the popsicle if you have one.

Be careful to put the microcontroller in the plastic bag and seal it.

Then you can place all three of them inside the container box with some ice on top of it.

I set the timer for 15 minutes. And the data will be recorded for 10 second delays.Check the coding. So the total data is about 90 ++ each for the microcontroller .

I extract the data from each:

• Uno - it is easy, just plug in the microSD card into card reader and you can copy from the card.
• Pico - a bit careful not to plug off the battery because the data will erase if you plug in the USB cable if you turn off the battery. Just plug the USB in the pico without detach the battery.
• Micro:bit - it is very easy from the rest of microcontrollers, plug in the micro USB into the computer, and voila, you can get in from the MY_DATA html file.

The next part is simple, you can copy these data from each microcontroller and paste it in Excel software or similar like WPS or libreOffice.

You can make a chart from these data. I choose the X Y scatter type.

So i had extend the experiment using only arduino Uno inside my freezer which i store my popsicles and ice cream :D

I don't do with pi pico and microbit because these two microcontrollers are more expensive to buy and i do not have the luxury to buy if they are broken :D

The experiment turn out to be shock for me, because the temperature inside the freezer reach almost -25℃ !

Maybe next time i will have the luxury to carry out with the pico and the micro:bit.

If you look at the data which I have collected, the arduino Uno can read the temperature of the ice bag almost for 1.4℃.

The pico read about 9.25℃ . And lastly the micro:bit can read only 15℃ for the same ice bag and in the same box(environment).

If we can derive the temperature for the ice/inside the box for about 0℃ (because the ice still in the form of solid) and we can say the arduino UNO win this ice challenge!

But you may disagree with me. And its time for you to try this challenge!

Thank you very much for your reading. Hope you can enjoy this little experiment later.