Tag Archives: Picoborg

PicoBorg Helps To Build a DoodleBorg

Imagine a small tank driven by a Raspberry Pi or RBPi. This is the DoodleBorg, a two-horsepower goliath and is the most powerful robot controlled by the RBPi. Powered by starter motors originally from a motorcycle, the DoodleBorg uses six PicoBorg motor boards made by PiBorg.

The DoodleBorg uses a tiny, credit card sized single board computer, the RBPi, as its brain. It has six reverse motor controller boards or PicoBorgs controlling its six wheels. Each of the boards is capable of handling 10A on average. Therefore, with two batteries in series, the average power output is 6x10x24=1440Watts or roughly 2HP. Peak power outputs are higher, about 2.1KW or three horsepower. Usually, the RBPi is prominently visible in the robot it is powering. However, in this case, you will hardly recognize it in the massive size of the project. Commands to the DoodleBorg are sent via a PS3 controller.

The PicoBorg reverse motor controller cards were specifically chosen for this project. These are advanced dual motor control boards for use with an RBPi. PicoBorgs can control big or small motors, with forward or reverse speed control. Each board, with its own emergency power off, is sized to mount on your RBPi for PID control and feedback via the GPIO pins. If you need to control more motors, simply plug in more boards and control up to 200 motors.

The dual motor controllers can handle input voltages between 6 and 25VDC and control up to 5A per channel, that is, 10A when combined. The emergency power off switch works in both bidirectional and speed control modes. PicoBorg boards are capable of handling two DC motors or one stepper motor with 4- or 6-wire configuration. For communication, you can use the I2C or SCK/SDA pins on the GPIO together with 3V3/GND pins. Adding the PicKit2 brings additional functionality.

PicoBorg reverse motor controllers are protected against overheat, short circuits on all outputs and under-voltage lockout. Connections are very straightforward. Six screw-terminals on the board allow connecting two motors and a battery. There are two 6-pin terminals, one of which is for connecting to control signals from the GPIO of the RBPi. The other 6-pin terminal can be used for daisy chaining another PicoBorg board.

Another connector on the board allows you to easily add a normally closed switch to act as an emergency switch. In case of any fault, simple open the switch and the motor will be cut off. The software on the PIC micro-controller on board will recognize the emergency switch operation and prevent further operation of the motors until enabled by a software command.

Another feature of the PicoBorg is its ability to run DC motors with taco feedback. The software accepts taco input signals that indicate either the number of rotations or the distance traveled by the wheels. Acceptable feedback signals are – quadrature signal (A or B) from an encoder, taco signal from a computer fan motor, index mark feedback such as one per revolution pulse. The motor connection remains the same as that for a standard DC motor setup.

Do Even More with your Raspberry Pi

When you own a Raspberry Pi, there is so much you can do with it. However, combine the bare Raspberry Pi with some attachments, and you have a gadget that could far exceed your expectations. Presented here are some of the more useful attachments, which will increase your expectations from the Raspberry Pi.

LCD Option from 4D

When you want to exploit the full HD capabilities of the Raspberry Pi, give it the color LCD options from 4D Systems. The company’s EVE (Extensible Virtual Engine) that is featured by the “Picasso Processor” drives the 480×272 pixels on the TFT Screen of the 4.3-inch “uLCD-43-PT-Pi”. This gives you 65,000 true to live colors on a 4.3-inch diagonal screen. The 4.3-inch screen is notable for its resistive touch layer, which can sense both finger as well as stylus interaction.

When you are going portable with your Raspberry Pi, this screen will be absolutely essential. To connect with the Raspberry Pi, this series of LCD screens from 4D has a “4D Serial Pi Adapter” that connects to the GPIO port of the Raspberry Pi board, through a 5-way cable adapter. The best feature of this adapter is it does not hog all the GPIO port, but allows for duplication of the GPIO lines, so that you can stack another board on top.

AlaMode

A team of like-minded students and engineers has made the AlaMode board that has some special features. Working off the Raspberry Pi GPIO port, AlaMode is a stackable board compatible with Arduino. The goal of the Wyolem Team was to provide the Raspberry Pi and its user’s access to the vast library, devices and “Shield” expansion boards available for the Arduino and its community. This allows you the complete freedom to program the Raspberry Pi in any language you prefer and control the Arduino or the AlaMode directly.

The AlaMode takes its power directly from the Raspberry Pi, or you can power it separately from USB, wall-mart or external batteries. For application memory support or for data logging, a micro-SD card slot is added. You also have a real-time clock (DS3234), which reports its time back to the Raspberry Pi, thus removing the necessity to program two clocks.

You can even connect a Fastrax UP501 GPS receiver module on the AlaMode. This opens up the Raspberry Pi to the expanding stackable shields of the Arduino.

LCD & Keypad Kit