Board Designer

WebbotLib Board Designer

This Java application can be downloaded here and will create shortcuts on your desktop.

The board designer allows you to either create a board from scratch, or to use an existing design as a starting point.

To design a new board you need to specify the Processor (chip) and then one of its package formats. Each chip may come in several package formats such as TQFP, PDIP etc - and this packaging can effect what pins are available.

If you select a PDIP format then I generate a default image of the board. If you want to modify the image, say by using a photo of the board, then you can drag and drop the image of the board into the main view area. NB Photographs of the board should be taken looking straight down at the board.

The application now shows a picture of your board.

You can now drag processor pins from the displayed table onto the photograph to represent a new header pin (shown in green). Once you come to adding new devices to your project then the system will only look for processor pins that have an available header pin.v

The next table lists the available power busses available on the battery. By default you should see a 'Battery (5.5V-7.2V)' and 'Gnd'.

These represent 'unregulated power supplies' - ie the connection from your battery that is used to power the board. 

The battery shows 5.5V-72.V as this is a 'reasonable' value for most boards. If your board expects a battery with a difference tolerance then double click on this entry and change the minimum and maximum possible voltages.

Your board probably has header pins where this battery voltage and gnd are available. To indicate thee position of these power header pins then you can drag and drop from the power bus table onto your image.

Unregulated power supplies are fine but your board will also have one, or more, regulators to convert the battery voltage into, say, 5V and this 5V supply may then go to another regulator to produce 3.3V.  These regulated voltages, amongst other things, will be used to power the chip.

To add a new reulated power supply then click on the Add button in the power bus table and then choose 'Regulated'. You will be prompted for the output voltage, the maximum current, and the power source.

So if you are using, say, a 7805 regulator to create 5V from the battery then the values will be: voltage=5(v), maximum current=1(Amp), power source=Battery.

The regulated voltages can be cascaded - ie if you are using a different regulator to convert the 5V supply into 3.3V, at say 75mA, then the values would be: voltage=3.3(V), maximum current=0.075(Amps), power source=5v.

So why do we do this? Well it means that WebbotLib knows what regulated voltages are available and how much current they can supply. So when we come to add devices to the board then we know how much current is being drawn from where and whether or not this is within the allowable limits or whether it will melt the regulator. All of the regulated supplies will originate from an unregulated battery - when creating a project the user willdeclare the actual voltage and actual mAH rating of the battery - and so we can anticipate the expected battery life.

Finally: we can drop and drag devices from the list at the left of the window to show all of the devices built into the board. Most boards have USBs, LEDs, or switches built onto the board (otherwise its just a chip right?). This process is described in more detail for the Project Designer (as projects use different devices: sensors, servos, motors etc). The only difference when using the Board Designer is that the power supplies for these devices is implied (ie they dont need header pins).