Robit is a motherboard for a micro:bit based smart car.
It is compatible with MBOT. With most of the features of MBOT, with the addition of 4 DC motor connectors, 2 stepper motor connectors and 8 PWM signal output. You can use it to drive PWM signal devices like servos. It has 8x G-5V-S digital signal connectors. Robit can gives you all the basic functions of MBOT. Additionally, you can extend its features with more sensors, motors, servos, stepping motors, etc.
Pins & Connectors
Introduction of Major Components
Robit has 4 RJ25 connectors. Each RJ25 connector has 6 touch points. These points respond to power, 2 IO ports and I2C ports separately. It is compatible with some sensors on mBOT.
|RJ25 Connector||Pin mapping to micro:bit|
|J3||SCL(P19)/SDA(P20)/GND/5V/P1/P2 (support 5V analog input sensor)|
|J4||SCL(P19)/SDA(P20)/GND/5V/P3/P4 (support 5V analog input sensor)|
GVS Standard Electric Brick Connector
In addition to the RJ25 connector, the I/O port on the micro:bit also interfaces with 5V components. P1/P2/P3/P4 supports 5V analog input sensors.
GVS Standard Servo Connector: S0~S7
You can connect 8 servos in total. This connector leads out from the chip PCA9685 and extends from the I2C connector on micro:bit instead of normal I/O ports.
DC Motor Connector: M1~M4
It allows you to connect 4 DC motors (max) at the same time. This connector leads out from the chip PCA9685 and extends from the I2C connector on micro:bit instead of normal I/O ports.
Stepping Motor Connector: STEP1 & STEP2
It enables you to connect (max) 2 stepping motors (28BYJ-48-5V).
The buzzer is connected to the P0 port on micro:bit.
The light sensor onboard is connected to the P10 port on micro:bit.
Infrared Emitting Diode
This infrared emitting diode is connected to the P6 port on micro:bit.
Infrared Receiving Diode
This infrared receiving diode is connected to the P8 port on micro:bit.
Two rainbow LED beads are connected to the P12 port on micro:bit.
DC Power Connector
DC power connector supports 3.7V~4.2V DC power. It is usually connected to a battery holder with 4 AAA batteries.
Li-battery connector supports 3.7V~4.2V li-battery.
This indicator tells you battery power information with status blinks. Blink once means 1 grid of power. And the full power has 4 grids. That means it will blink 4 times when the battery power is full.
This connector is only used to charge li-battery. It doesn't support data transmit and its charging current is 500mA.
Fix robit onto mbot car.
Connect left motor to M1 port, and right motor to M2 port.
Once completed, it looks like the following picture showed.
Click to open makecode, search the key word "robit" and add robit package.
Write your code to make the car in the forever block
to move forth and back for 3 seconds. Here's the code:
You can see the whole program from the link here:https://makecode.microbit.org/_aXVAyx3dm585
Also, you can download the code directly from the page below:
We can see our robit car moves forward for 3 seconds, and then backward 3 seconds. This round trip movement is repeated forever.
|DC Power Input Voltage||DC 3.7-6V|
|Li-battery Input Voltage||DC 3.7-4.2V|
|USB Recharging Current||500mA|
|Extendable Analog IO Ports||4|
|Extendable Digital IO Ports||10|
|Max Stepping Motor Driven Quantity||8|
|DC Motor||4 Channels|
|Stepping Motor||2 Channels|
|Programmable LED Beads||2|
|Dimension||90mm X 74mm|
1 x Robit