Enhanced Spider Robot With Arduino Nano

This spider robot is suitable for kids.

My version will have two operating modes:

Remote control using bluetooth module (HC-06) and an Android phone app. This is the default start-up mode.

Autonomous line-following. This mode is selected through an Android phone app.

Let’s start building.

Step 1: What You Need?

2 x Spider Robot Kit
4 x Ni-MH Battery/ Charger combo and AA Battery Holder
2 x IR Line Tracker Sensor Module
1 x On-Off Switch
1 x Mini Breadboard
1 x Arduino Nano
1 x Motor Driver ( Using TB6612FNG Breakout but L298x Based driver should work just as well)
1 x HC-06 Bluetooth Module
1 x 9V Step-up Booster ( 4 x Ni-MH is only 4.8V). While motors will use 4.8V, I need to boost voltage to 9V to power Nano through Vin)
1 x Mini USB Cable
Male-to-Male Jumper Wires
Approx 4" x 4" Cardboard (Used as platform)
1 x Computer with Arduino IDE

Optional
Soldering Iron & Solder
Battery & Charger
XL6009 DC-DC Adjustable Step-up Voltage Booster Module
USB To Power Jack Cable Female-to-Male Jumper Wires
Female-to-Female Jumper Wires
Cable Cover

Don't have components? Don't worry. Just click the component's name.

Step 2: Chassis

See http://letsmakerobots.com/node/37661 for building the base chassis. While 8 leg linkages are obtained from a single kit, you’ll need to use following parts from another kit to complete the chassis:

Motor and body

Axle

Leg linkage case without gears (This is used for joining two independent leg linkages)

Cross beam

Since the built-in battery housing on the body pieces are not needed in my design, cut off about 3mm from the height and glue the platform cardboard on top. Use leftover plastic pieces to build a truss to support the platform above motors and build mounting beams for IR line tracking sensors between two motors.

As for the on-off switch location, I put that on next to the battery pack. This required cutting the plastic underneath the platform. I think the better location would be between the cardboard and the plastic body underneath the cardboard and use a glue gun to secure it.

Step 3: Build Your Circuit.

Wire all the components according to the diagram. You’ll notice that I use 9v step-up boost converter to power Nano through Vin pin. This eliminates having another 9V battery for the logic. Motors are still powered by 6V or 4.8V if using Ni-MH rechargeable batteries.

Step 4: Android Mobile App

While I could have built my own app using MIT App Inventor, why reinvent the wheel when there are numerous already written apps that fit for this purpose? I downloaded few from Google Play to evaluate them and eventually decided to use Arduino Bluetooth Controller. In Controller Mode, I customized following buttons to send specific characters that are recognized by the code.

Left = “l” (turn left)

Right = “r” (turn right)

Up = “u” (go forward)

Down = “d” (go reverse)

X = “s” (stop)

Select = “t” (toggle between RC and Line Following Mode)

Step 5: Upload The Code.

Comments in the code should explain what’s going on in the code. It was written for Nano but it should work on other Arduino boards with no or little mods.

Step 6: Done!

The kit comes with a motor that is designed for low voltage/high current environment. When using an H bridge driver such as TB6612FNG, it’s better to use high voltage/low current motors. This may explain why, with heavier alkaline batteries, it couldn’t lift the body up to take a step.

CV.JAYABARUMANDIRI

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