Hardware components

We base our development on Makeblock's mBot Ranger. We will use its chassis, wheels, motors and microcontroller, and remove the sonar, infrared sensor and batteries. A single board computer —Intel's UpBoard— is the core of the mk-ros, while the Arduino microcontroller controls and powers the motors and IMU.

The following is an overview of the components we used. Some might not be available anymore so you will need to find one with the same functionality.

Component	Approx. Price
Matek Double Regulator UBEC DUO	16€
Two DC male connectors like this one
FLOUREON RC Akku 2S 7.4V 5000mAh	15€
SKYRC LiPo Charger	25€
SLAMTEC RPLIDAR A-1	120€
Intel AAEON UpBoard 4GB	220€
Makeblock mBot Ranger	175€
Spare parts from Makeblock https://www.makeblock.es/productos/placa_i1/ https://www.makeblock.es/productos/viga_0824_48/ https://www.makeblock.es/productos/mbot_pack_soportes/ https://www.makeblock.es/productos/pack_vigas_0412/

Caster wheel

We have tried two different hardware configurations for our robot: one using tracked wheels, and one using a caster wheel. The current mBot Ranger comes with some plastic wheel that should work as caster wheel but doesn't, instead you should use the wheel that was being sold with the earlier versions of the robot:

Avoid using the new 'caster wheel'

Try to get the good old caster wheel

Power supply

In the original mBot, a set of AA batteries powers the Arduino microcontroller. In order to power both the microcontroller and the UpBoard we used a LiPo battery connected to a double output regulator. We use the Matek UBEC Duo FPV Dual UBEC 4A 5V - 12V since the UpBoard needs 5V-4A and the Arduino can use the 12V to operate and power the motors.

The battery can be connected directly to the regulator. However you will need to do some manual work to solder the DC connectors to each of the outputs of the regulator. If you have never done any soldering there is plenty of advice online:

RPLidar A1

For assembling the Lidar you will need to get some extra parts from Makeblock (listed as "spare parts in the table above). The assembly will succeed on three of the four legs:

The RPLidar is quite heavy for our robot. Have this in mind and check from time to time whether the wheel axis are properly fixed to the motors.

The IMU on the Makeblock Auriga Board

Makeblock's Auriga board has an integrated MPU, namely the MPU-6050. It seems this chip was stopped being manufactured around 2019 (as discussed in this forum), and since then a clone is being manufactured named MPU-6050A. If you look on the back of the board, as specified in Makeblock's instructions, you can read on the chip which one you have:

Screenshot from the official documentation

We have one of each kind, and found the MPU-6050A to be more imprecise, and having a different axes configuration (though being mounted the same), with the X-axis pointing downwards.