BBC micro:bit V2 In-Depth - Major Upgrades!
Joshua Lowe@all_about_code
On October 13th 2020, the Micro:bit Educational Foundation announced the launch of micro:bit V2, a brand new BBC micro:bit which sees the biggest upgrade to the device since launch in 2016. V2 includes a built-in speaker and microphone as well as several other new features, opening up a new world of possibilities for micro:bit which enables users to get creative straight out of the box. The hardware also features several technical upgrades to equip the micro:bit for the future, making it the ideal tool for creative computing projects.
What's new?
The new micro:bit brings a whole host of new onboard features and tech upgrades whilst keeping all the things students, teachers and makers love about the original. This means the new micro:bit will be compatible with existing lessons, code and add-on boards that the original is.
Also, as part of the Micro:bit Educational Foundation's commitment to keeping the device as cost-effective and accessible as possible, the new device is the same price as the original which is impressive given the new features (and shiny new packaging!).
The updated micro:bit has been designed in consultation with teachers and the global community of micro:bit fans to ensure continuity and simplicity in teaching with the latest device. So without further ado, let's take a look at those new features in more detail.
Speaker
One of the big features the community have wanted on the micro: bit is now here, an onboard speaker! Gone are the days of connecting headphones or wiring up a speaker to create music with your micro:bit, the new onboard speaker on the back of the micro:bit V2 provides a great platform for getting started with the music functionality in MakeCode and Python. Making sound and music is one of the first things children and teachers do to get truly creative with technology in the classroom, so the addition of a built-in speaker was a natural next step for the foundation.
Using the speaker within MakeCode and Python is super simple. All you have to do is enable the onboard speaker for all the music commands within your editor of choice and use the music functionality like you would if you had an external speaker attached.
Below is a demo of the onboard speaker, taken from the "out of the box" program that is preloaded on the micro:bit V2. The speaker gives off a decent amount of sound making it perfect for classroom use.
With the built-in speaker, students can take their creativity to new levels with the latest micro:bit - compose music, give projects a voice and personality or build interactive, motion-sensitive instruments. The possibilities are endless.
Microphone
The second major upgrade is the onboard Knowles MEMs microphone sensor. This enables the new micro:bit to respond to sound and execute code accordingly depending on the level of sound. Just like the speaker, the microphone is placed on the back of the board and can be identified by a small gold rectangle. I tested the microphone by creating a simple project that would play some music with the onboard speaker when the microphone detected a clap.
Paired to the microphone is an LED which shines through the board illuminating a microphone icon. Every time the microphone is listening, the LED will turn on which I think is a really nice touch. The Foundation also state that the LED is a great way to teach about the importance of privacy and the impact listening devices have on our lives.
In MakeCode, the microphone is easy to use within your projects with blocks for getting the sound level and executing code on loud or quiet sounds.
A popular project is using the microphone on the micro:bit as a clap sensor, using the microphone in this way opens up a whole new world of projects that you can do with just a micro:bit.
Logo Touch
In addition to the two buttons as input devices on the micro:bit, there's now another type of input in the form of the micro:bit logo! On the original micro:bit, the micro:bit "face" logo was the same colour as the triangles, but now on V2, the micro:bit logo is a copper capacitive touch button that can be used as an input device just like the two buttons.
The logo touch functionality can be used just like the buttons in MakeCode too with on logo pressed and on logo released blocks to execute code on the touch of the logo.
Having another touch input device is really handy and with this addition, the micro:bit now has four unique ways to respond to touch input. A Button, B Button, A+B Buttons and the logo touch.
Sleep Mode + Power Consumption.
Another cool feature of the micro:bit V2 is sleep mode. By holding the reset button on the back for a few seconds you can activate the new sleep mode function. This will stop the running program on the micro:bit until you press the reset button to wake it up. This is really handy for lessons where you're using the speaker and want to stop the noise but don't want the hassle of unplugging and plugging the micro:bit back in every time. You can tell the micro:bit is in sleep mode with the new power LED on the back which is solid red when the micro:bit is powered on and running a program and pulsing when the micro:bit is in sleep mode.
As well as sleep mode, the new micro:bit is capable of lower power consumption, allowing for long-running data logging out and about. I can see this being really helpful for remote monitoring over LoRa and similar technologies.
Spec Upgrades
In addition to new features, the BBC micro:bit V2 has several spec upgrades. The processor has received a big upgrade to the nRF52833 from the nRF51822 which will enable people to run more demanding tasks like AI and Machine Learning. The flash memory has also doubled to 512Kb allowing bigger programs to be uploaded and the RAM has gone from just 16Kb to 128Kb, that's eight times as much!
Alongside this is more current for accessories. Add-on boards can now access over double the current than on the original micro:bit with the upgrade from 90mA to 200mA, this should enable companies to make more advanced and demanding add-on boards with the micro:bit V2.
The last two spec upgrades are the additions of a dedicated I2c bus for peripherals as well as Bluetooth 5.0 instead of Bluetooth 4.0 like on the original micro:bit.
These spec upgrades will open up a new range of possibilities for add-on board makers and will give the micro:bit more power to undertake more complex projects and tasks.
Notched Edge Connector + Capacitive Touch
Another noticeable change on the new micro:bit is the notched edge connector. At the bottom of each of the larger pins is a small cut out which will allow easier connection of croc clips. An issue many teachers had with the original micro:bit was that croc clips would often slip off the pin they're connected to, but now with the notched edge connector, you can connect the croc clip to the hole and the cut out on the pin so that they stay in place.
Another thing to note about the edge connector is the switch from resistive touch to capacitive touch. This means, for one of the large ring pins to detect input, you no longer need to complete a circuit! This is the same technology that is being used for the logo touch feature I talked about earlier.
Compatibility
A concern I'm sure many teachers and users will have with the new micro:bit is compatibility, this is something that the Micro:bit Educational Foundation have worked hard on to ensure that code can run seamlessly on V1 and V2.
Unfortunately, existing HEX files will not work, however, there is a simple fix. You will first need to update the hex files by dragging and dropping them into the code editor in which they were created and re-download the code. This will create a new Universal Hex File, a new type of HEX file that will run on both V1 and V2 micro:bits, so you won't have to worry about compatibility or select your version of micro:bit on download! A clear indication that you are working with this format is that a compiled .hex file will be ~1.8Mb as opposed to ~700Kb in size. The Universal Hex format has been developed to ensure the best experience for users when moving between board variants. If a V1 only .hex is detected on a V2 board it will throw an error, but a Universal Hex file will work seamlessly between both micro:bits. I think this is a really handy and important feature so that the V1 micro:bit doesn't feel left behind.
As for hardware compatibility, the new micro:bit will be compatible with the majority of existing add-on boards and accessories. The pinout on V2 has mostly stayed the same with the exception of the LED column pins being swapped around which not many add-on boards take advantage of.
Comparing V1 and V2
Of course, our article wouldn't be complete without showing you some comparison photos of the V1 compared to the new V2.
Below is the front of the micro:bit, with V2 on the left and V1 on the right. Not that many visual changes here apart from the copper logo and notched edge connector. Hidden on the photo is the exposed PCB for the microphone indicator.
Where you really notice a difference is on the back of the board. As you can tell a lot has changed on V2 (left). The radio/Bluetooth antenna is now at an angle and has a new copper finish to make it easier to identify.
In the middle of the board is the buzzer which is also at an angle (a theme with the components on the back on V2 which I really like!). Just above it in the form of a golden rectangle is the microphone and to the left of that is the upgraded processor.
You'll also notice that there are now three LEDs on the back of the micro:bit V2 compared to the one. These are for the microphone indicator, flash LED and power LED which I covered earlier on in the article.
Staying the same as on the V2 is the JST battery connector, reset button and micro USB port (which I would have liked to see upgraded to USB C but understand the reason behind wanting the v2 to be a drop-in replacement for current V1 users)
As mentioned earlier, there is not much change to the pinout of the V2 to ensure compatibility with resources and add-on boards. Below is a chart, courtesy of the Micro:bit Educational Foundation showing the differences.
Final thoughts on V2
I really like the V2 micro:bit and feel that it's a great board to build on the success of the original. Adding features like the onboard speaker and microphone add a whole new world of project possibilities for those getting a micro:bit for the first time as well as long time users of the micro:bit.
The new micro:bit now adds so much more out of the box without the need for add-on boards, further improving what you can do with just a micro:bit and nothing else. What's more is the fact the Foundation has stuck to the same price point, showing their commitment to ensuring everyone can access the new and improved micro:bit.