MI:power board for the BBC micro:bit

Can you pair a microbit to an ipad when attached to the MI:Power board? I can't seem to get it in pairing mode.

Hi Tom,

Thank you for your message, you can do what you would need to do is press and hold the A and B buttons down and then turn the power switch on and offer and this should put the micro:bit into pairing mode as the power cycle acts like pressing the button on the back.

Best regards

Cullen

Hello, We have both the Mi:Power boards as well as the Kitronik Halo, however when running both (And powering both independently), It doesn't seem to work correctly. A Halo set with 24 red LED's will light up LED's 1-3 with random colours instead. Would it be possible to power both the Micro:bit & the halo both off of the Mi:Power? Or will we have to choose between one or the other. Many Thanks

Hi Henry,

Thank you for your email, this will likely be because the mi:power has it's buzzer connected to pin 0 and the zip LEDs are also run from pin 0 on the halo. So the two are going to be conflicting. Also depending on how you have it all connected you may not have the GNDs twinned so that could cause further bugs and glitches.

The Halo needs more power than the Mi:power can run so you could not run it from the power board. The micro:bit will be fed power by the ZIP halo however so there should not be much need for a Mi:Power at that point.

I assume the reason you want both is for use with the buzzer on the Mi:Power? If this is the case then you can attach a buzzer to one of the breakouts on the Halo. Alternatively as a sneaky heads up in the near future there is a board that will combine LEDs and buzzers that might fill the niche you need.

Best Regards

Cullen

Can the cell replaced with a rechargeable one? If so can it be recharged leaving it in the board? Thank you

Hi Giorgio,

Thank you for your question as long as it's a 3V CR2032 coin cell it should fit. You would not be able to charge the kit while the coin cell is in the kit though to the back charge protection on the board in place for normal coin cells.

Best Regards

Cullen

Hi I am getting this motorbike case but I am also looking to purchase an addon that requires the pins. Will it be able to fit over the screws??

Hi Sidhu,

It depends on the kit but most likely it will not be able to in my experience.

Best Regards

Cullen

We purchased MI:Power to be both a portable power supply and to provide high-volume ("75dB!") sound for music programming in micro:Python, but when we compared to just a micro:bit connected to a speaker, the MI:Power was weak then would click to even weaker every other speech.sing(''.join( )).

This was actually a real hassle, as we had already cut our enclosures.So we almost gave up the project, until someone tried just the micro:bit + speaker alone, and identified the problem is in the MI:Power.

You mention the 'music function'? There are no music projects in your resources, except a pitch tone music tuner. So if I read this right, all you can do is Make Code is various pitch tones using pin 0 and pin GND, whereas the micro:bit can say, pronounce and sing using pin 0 and pin 1, with a battery pack or USB and micro:Python.

Is there any way to code the MI:Power piezo chip to recognize Micro:Python commands for speech/song:
from microbit import *
import speech (creates highly intelligible synthetic speech and song)
import music (just plays pitch tones like your Make Code)

Hi Anton,

Thank you for your question we have been doing a few tests ourside to double check for you.

We ran some tests with a Mi power to test the sound output with an App. We didn't do much calibrating with the app but it was still getting a reading of 68dB from the Mi Power board so it seems that is all okay.

We designed the mi power a couple of years back so we hadn't really done much with the micro python blocks for sound as most weren't written then. We tried run the codes from micro python with a speaker and the mi power. To be honest they were pretty similar when we tried them. The music worked fine through both when we used import music code.

We found the voice and speaking to be hard to understand on both. You could kind of make out what it was saying if you knew what you were going for but not really.

At the moment there are no plans to make alterations to the mi power as it is primarily intended as a small profile power source for the micro:bit to run from but I have passed all this feedback onto our R and D department.

I purchased 2 MI:power board for the BBC micro:bit from Pimoroni. Both were working just fine until I tried changing the code on the micro:bit while the power board was connected, but the switch was off. After that, the micro:bit works just fine, but it can no longer be powered by the board. And yes, I tried a new battery with the same results. I have not seen it specified anywhere that you cannot plug the micro:bit to your computer while connected to the power board. Did I accidentally fry the boards? How can I tell? Is there some troubleshootingI can do to get it working again? If not, is there a warranty on this?

Dear Cecilia,

Thank you for your question. Being plugged in while the mi power board should not cause an issue as the micro:bit contains a diode which will ensure it always draws from the highest voltage current, in this case the USB cable.

I would try swapping the mi power boards over and see if the issue follows the micro:bit or mi power board. The other thing to check is whether the micro:bit still draws power from a JST connected battery pack.

It is more likely to be a faulty micro:bit than mi power from what you have described as it is possible a regulator on the micro:bit has blown when it was connected to 5V. The checks above should help determine which piece of equipment is at fault.

Once you have established that I would recommend emailing the manufacturer for the product. If that was ourselves please email support@kitronik.co.uk and we will do our best to help.

I love your laser cutter downloadable files to make accessories. Can you please add .STL versions so that schools can 3D print these? Many thanks!

Hi Daniel, It's great to hear you love the designs. I can check with R&D to see if this is possible and will get back to you.

The buzzer you use on the power board is better than other buzzers/speakers I've been experimenting with. Do you sell them on their own, or is there a part number where I could source them elsewhere?

Hi Peter,

Unfortunately that part is a buzzer that we surface mount with our in house machinery so is not suitable for general purpose, as you would need a pick and place machine.

Best Regards

Cullen

One should be careful when using the MI:power board NOT to plug the Micro:Bit into a USB port at the computer. Even with the switch set to "off", the KL26Z USB chip on board will start to overheat, and, eventually, overheat, causing permanent damage to the Micro:Bit. I experienced this behaviour with two Micro:Bits, so it is repeatable.

Hi Holger, With regards to the issue you are experiencing I can confirm that having the MI:power board attached won’t be the cause of this. There is a diode both on the MI:power board and on the micro:bit which ensure that power is only drawn from one source at a time. It will draw power from which ever source has the highest voltage. As such the issues you are experiencing are related to the micro:bit units themselves and it is possible you have received a damage unit(s). As such it would be best to contact the supplier you received these from, if it was ourselves please contact support@kitronik.co.uk.

Hi, how can I test that its working? Currently I am just unplugging the USB and just flicking the on switch, but nothing happens. I think the battery may be dead... what steps can I take to solve this? Note: I just got it, so it hasn't been used and I don't know if its faulty.

Hi John, the easiest way to test this is to upload some simple code that turns P0 on and get this to output a frequency between 200Hz to 10kHz, this should then make the buzzer sound. You also need to ensure the battery is correctly inserted and that the screws are making contact with the micro:bit.

Is it likely to break anything/cause overheating if the battery power is not switched off before the micro:bit, powered by this power board, is plugged into a USB lead connected to a computer (so that the micro:bit is connected to two power sources at once: the coin cell and the computer (through the USB lead))?

My gut reaction is that it would be a really bad idea to have two sources of power connected at once but I don't have the requisite knowledge to be able to judge and it could well turn out that I'm wrong.

Hi Graham, it shouldn’t break anything if the power is left turn on with the MI:power board and it is plugged into the USB port, it would be similar to if the battery cage was left plugged in when it was plugged into the PC. However it is recommended that only one device is used to power the micro:bit at any one time.

Is there a way to monitor remaining power level?

Hi Dan, There currently isn’t anyway to monitor the remaining charge in the coin cell battery. The easiest way would be to measure the voltage on the 3V pin on the MI:power board, using a multimeter. You may also notice the LED’s on the BBC micro:bit getting slightly dimmer.

I'm looking at an application that is going to be polling sensors at a high frequency and over a long time period so will likely eat batteries. I'd therefore like to use rechargeable LiR2032, but these seem to be 3.6V. Is the over voltage likely to be an issue, or is there some form of over voltage protection built into the Mi:Power board (or Micro:bit)?

Hi Mark, Unfortunately there isn’t any voltage protection built into the BBC micro:bit or the MI:power board, however there is a diode on the MI:power board which would lower the voltage slightly (0.1-0.2V). We however can’t guarantee that this would protect the BBC micro:bit as the power supply should be 3V’s.

I am currently using this board, however, setting P0 output to High is not creating any sound. Is setting that pin to High (1) and different than using the music functions?

Hi Dan, setting the pin high won’t do anything, as sound is a vibration so you would need to swap the pin from high to low very quickly. Using the music function is the easiest way to do this.

If I am using MI:power board to power the micro:bit will it damage the micro:bit if I plug it into
my USB port if the MI:power board is switched on?
I assume it is safe to power the micro:bit via the USB port if the MI:power inboard is switched off.

Hi Hugh, there shouldn’t be an issue, it would be a similar situation if you were using a battery cage to power the BBC micro:bit and left that plugged in while connecting to a PC. However it would be advisable to always turn the MI:power board off before connecting to the USB port.

Depending on what it's doing, how long could a micro:bit run from a Mi:Power board?? Thanks :-)

If the BBC micro:bit was connected to the power board and was just used to scroll text across the LED mounted on the board it would last between 10-20 hours. Once you connect items to the outputs this would alter.

I see from the end of the video that you put the power board inside a case. Is this the standard MI:pro case?

The case shown at the end is for the MI:power board and the BBC micro:bit, this is a new case that we are currently in the process of introducing and will hopefully be available on the website in the near future.