T his is a low-cos t expansion board for Micro:bit, w hich is specifically used for r the IO ports of Micro:bit. It ha s t a ken a ll the IO r esourc e s on the Micro:bit, and so has a buzzer on the board. It is connected to the P0 pin through the jumper ca p. The P0 pin can be released using a jumper cap. The small size is very suitable for small project s using Micro:bit.

Features

S m all size, very suitable for DIY

A l l IO ports are extracted

O n -board buzzer- you can directly use the m us ic module in MakeCode to play mu si c . At the same time, the 3.5mm audio connector on the board can be connected to audio equipm e n t ; such as, headphones to have more creative endeavors.

T w o LEGO-compatible pin hole s for easy assembly and in te gr a tion

T h e 3 P IN interfac e is distingu ished by yellow , red, and black. It is created so that plugg i ng it in the wro n g way is difficult, and it is convenient to plug in the sensors.

I t imi t ates the 5PIN gold fingers on the Micro:bit. This is convenient for ma ke rs w h o like t o use the alligator c lips.

C o mpare d with IObit1.0, the biggest differe n ce is t hat it can input and output 5V, support 5V sensor use, and increases the drive capacity (can drive multiple 9g small servos).

I ncludes 1A self-recovery fuse

C u stom-designed silk screen board

Product parameters

L e ngth x width x height: 57mmx44mmx12mm

Technical parameters

P o wer supply mode: Io b itV.2.0 supports USB5V power supply . This power supply m ode requires pr es sing the blue p ower switch .

Wo r king voltage: 3V-5V (5V sensor module is n ot s up ported under 3V power supply)

Ou t put current: 3V and 5V power interface with maximum output 1A

Se r ial port extraction: serial port can map IO port

I2 C port leads: pins 19 and 20 can only be u sed as I 2C function pins. They cannot be read and written as ordinary IO ports, because Micro:bit bottom is dead.

Sp i port leads; 14, 15 (IO port can be read and written).

Pr o gramming:

MakeCode/KittenBlock (ba sed on Scratch3.0) wit h h a rdware: M icro:bit.

Specifics:

It is consi s tent with Micro:bit programming, because IO bi t does not have its own drive chip (except buzzer). The building block that is generally used with IObit is to operate the IO port. Many sensors on the market return a high and low voltage. Flat, or an analog value. For actuators, the microbit needs to output high and low level to control. People who are not familiar with this aspect can s e arch Netease Cloud Classroom: Xiao y an Technology and find the arduino tutorial, which explains h o w to use the commonly used sensors on the market, the principle is the same.

W it h common building blocks -> pin

Be f ore using the building blocks, you must first understand the control method or reading method of the electronic module you are using.

Di g ital reading

Mo s t newbies will fall out of here because they often ignore setup pull-ups or pull-downs during initialization. So the level state will fail after reading it once. The re fore, we must pay a ttenti o n to this. Micro:bit itself does not help to set u p and down by default, you need to set it yourself.

Ana lo g reading

In r esponse to the analog reading, because the analog reading will return a value of 0-1023, it is always inconvenient to display it with a dot matrix screen. So here we take advantage of the unique serial port debugging function of the Make C ode offline version produced by Xiaoyan. First, download the program shown in the figure to open the serial port. In step 2, the console of the device will appear, you can see the data returned in real time.

Dig it al writing

Digi t al read here does not need to set up and down

An a l og write

Simul a ted writing an example of a flashing light

The m os t commonly used IO port operation is one of these four types. After you master it, you should have no problem with the commonly used sensors on the market. Another thing to note is that the sensors on the market are 5v and 3.3V compatible. But some can only work in 5V. For example, the blue ultrasonic wave that Taobao sells can ordinarily only work in 5V. If IObit is connected, the number read back will always be 0, because the module is not working properly!

I ntroduction to IObit hardware:

5V p o w e r

Insert the USB power supply (5V 1A) as shown in Figure 1. Press the blue butt o n at 2, and the red indicator light at 3 will light up. You can use the left 5V interface.

P0 buzz e r

To g gle s witch to tu rn off the buzzer function (see the silk screen on the back of t h e board for status)

3Pin IO por t leads

All the pins in the Micro:bit have been taken out without any reservation (Note: there are no P17 and P18 on the Micro:bit, it's not that the IObit is not taken out)

Yellow c orresponds to the different IO pins

Red cor r esponds to 3.3V/5V (with silkscreen)

Black c o rresponds to GND

5PIN go l d fin g ers

The gol d f in gers o f the Micr o :b i t are used to draw 3v, gnd, P1, P 2, and P3 respectively. This is for users who prefer to use a lli gator clips

40P Mic r o:bit horizontal socket

Compact socket size

Board m o unting holes an df i xing

Th e two o utermost holes a re approximately 4.8 mm in diame ter and a re compatible with Lego friction p ins with a spacing of 48 mm.

3.5mm au d io interface

Y o u can p lug in a 3.5mm jack audio device and play the sound of the P0 pin.

IO b it programming use:

If you h av en't gotten started with Micro:bit, first get started with Micro:bit, this is the operating premise.

Use m us ic bl ocks directly in MakeCode to CQ0056.png

P0 pin is

If you use P 0 , remember to turn the buzzer toggle switch off (because the buzzer is combined with P0)

When using th e Micro:bit power supply, IObit IO port drive capability is very weak, IO port current is less than 200mA, please do not connect high current devices (such as large servo MG995, DC motor), otherwise it will burn out the Micro:bit , you must fully understand before using what the device current conditions needed

When using a 5 V external power supply, you can drive multiple small servos, but please note that the maximum current is 1A!

If you use the high-low read function of the pin, you must set the pull-down on the pin.

If P0 is used as a normal IO port, the buzzer toggle switch must be turned off, otherwise the buzzer will sound or the IO read value will be abnormal.

Use the shared pi n with the Micro:bit dot matrix (such as 3, 4, 5, 6, 7, 8, 9, 10, 11), remember to disable the dot matrix screen on the software, otherwise it will be a bit of a screen burst

Do not use IO19, 20. 19 and 20 cannot be used as an IO port. Although the display on the MakeCode software can be used, it is actually not used! It can only be used for I2C communication

The USB port all ow sa maximum input current of 1A.

Do not place it on a met al surface to avoid short circuit