I’ve been asked by a few people from different places if there is a simple way to use an Arduino to build robots. I explained there are ready made boards like Roboduino, Romeo, Motoruino, etc. that can be used. Or a make custom compatible board. I told them that I used both ways, mostly because Roboduino doesn’t have an H-bridge onboard, so I designed my own customizable board, R-Dev-Ino. Usually people are puzzled with all that information, as they have heard about Arduino, some have used it in art projects or so, but did not hear about the other variants. Seems complicated…
Of course, one can buy a prototyping shield and a breadboard and make their connections on the breadboard. This route usually leaves no room on the breadboard for other experiments, like testing out different sensors or actuators. Also, the user has to have some electronics knowledge to make the connections. Even more complicated…
How about a shield that brings all of the good things together? Ready made 3 pin headers for sensors and servos but also an on board H-bridge that will drive most miniature motors? What if we add a mini breadboard to it? We will have a shield that allows the user to plug and play some parts, experiment and learn more about robotics.
Why a shield and not a stand alone robotic board? Using an Arduino with a shield form factor allows the user to add more functionality to their robot through other shields like the xBee shield, the GPS shield, the WiFy shield, the LCD shield and so on.
So I have designed a first prototype of the Robot Builder’s Shield. Features:
- 6 servo connectors (power from battery, digital pins 8-13),
- 6 sensor connectors (regulated 5V, all analog pins),
- a serial connector (for an external serial LCD for example or anything else),
- a SN754410 H-bridge (1 amp per motor, digital pins 4-7, uses Timer0 for PWM),
- space to attach a mini breadboard,
- connector for separate battery for motors and servos
- pins 2 and 3 (external interrupts) are not used.
I did not add a pin 13 LED as it is on the Arduino. Possible add ons are a tiny reset button and a connection from battery to the Vin pin, perhaps a power switch. Also caps near sensor and servo connectors…
Here is a picture, the blue is the bottom, GND plane, the red is the top, 5V plane. Round pins are male, oval pins are female. The hashed area is for the breadboard.
I’ll have the first batch in a couple of weeks, but I already thought of some improvements for the second revision. I am holding off sending another order until I test the first boards to see how I can fit in some more features and a prototyping holes under the breadboard, just in case the user does not need the breadboard. And I have to double the pins to be able to use the breadboard and more shields. I also want to add jumpers for the H-bridge control pins, just in case the user does not use it or wants to connect it differently.