SiRoAT - a Robot for 5 Volt Microcontrollers

SiRoAT stands for Simple Robot Arduino Template. After building SiRo, a simple robot for microbits, I got the idea to make a robot that is able to work with many different microcontrollers. In that way our robotics clubs could make a handfull of robots and then use them to introduce kids to a mix of different microcontrollers. I especially wanted the robot to be able to be run with either an arduino nano, NodeMCU or ESP32 Cam.

I also disliked the caster wheel on SiRo. Not all caster wheels have the same dimension and that makes it hard for people to buy the right caster wheels for the robot. So I removed the caster wheel, but instead I 3d printed a support. It makes the robot simpler to build, but it also take a lot longer to print it. SiRo can be printed in about an hour and a half on my printer, but SiRoAT take 4 hours.

The parts are pretty cheap and the materials should cost less than $20. Depending on where you live and the microcontroller that you use of course.

Materials:

4 x M3 30mm screws

2 x M3 6mm screws

4 x M3 Spacers

8 x M3 nuts

2 x TT130 motor

2 x Wheels for the TT130 motor

L298N Dual H Bridge motor controller

1 x Mini breadboard

1 x 9 volt battery + battery holder

A bit of wire. In two different colours if possible

Male-Female Jump wires

A small piece of double sided tape

Filament for the 3D-printer

Tools:

3d-printer

Soldering Iron

Screwdriver

Wirecutter

First step is to slice the stl files in your favorit slicer and print out the chassis and holder.

Then assemble the two parts. You might need to give it a drop of glue, depending on your printer.

While waiting on the 3d printer you can start by soldering wires on to the motors. Take 4 pieces of wire, each should be 12 cm, strip them and solder them on to the motors. If you can, then I would advice you to use two different colours of wires. It just makes it easier to keep track of them.

For next step we need 4 x 30 mm screws, 4 nuts and the motors.

Install the motors as shown on the picture.

First install the Spacers on the L298N.

Use the screw connector terminal to install the battery holder to the holes to the left and in the middle.

Then connect two wires to the middle and right holes.

Install the L298N on to the chassis.

Then screw the wires from the motors on to the L298N.

Put the wheels on to the motors.

Remove the protecting paper from the mini breadboard and put it on to the holder.

Take your a piece of double sided tape and place it at the rear of the smar car and put the battery on top of it.

Put jumpwires on to the L298N. You should be able to put 4 jump wires on to it, using the female connection on the wire.

Now put the microcontroller you want to use on to the breadboard.

The wiring will depend on the microcontroller you want to use and the pins you want access to.

The two wires connected to the screw connector terminal on the L298N supplies 5 volts.

The jumpwires controls the motors in pairs.

So the two to the left controls the left motor. The two to the right controls the right motor. To drive the motor one jumpwires needs to be high and the other need to be low.

You can see two examples here. One with an arduino nano and the other with an ESP32 Cam.