40 Pin AVR Development Board

Dedicated Power Supply Area

This board has a dedicated power supply area with support for many different configurations including:

• Voltage regulators with IGO or GOI pinouts
• Different connector options including barrel connectors, polarised headers and terminal blocks
• Optional diode and PPTC resettable fuse
• Multiple capacitor configurations, button battery and AVCC Filter

Based on a Breadboard Layout

The prototyping area on this board is based on a standard breadboard with a few of our own improvements.

• Power busses are pre routed on the board
• Power busses go from edge to edge and do not have any gaps
• Power busses are available in the gap were DIL components usually sit. This provides more flexibility for component placement and allows for more options for connecting power to components.

Screen Printing on Topside

Screen printing on the board top clearly shows power busses and connection points. Positive power rails are marked in solid white while the ground rails are marked with a white outline.

Connection Strips on Top and Bottom Edges

Most Protostack protoboards have sets of 3 connected pads on the top and bottom edges. These are used to interface each board with the adjoining board above/below or to interface the board with an external system. These strips can also be used as regular breadboard style connection strips.

Standard Protostack Form Factor and Mounting Holes

Protostack large boards have a standard size with 6 mounting holes on the top and bottom edges. This allow the board to be stacked with other small, medium or large boards using hexagonal spacers.

You can read all about board stacking here.

Lead Free HASL Pad Treatment

Hot Air Solder Levelling (HASL) is a process where the board is immersed in a molten tin-copper alloy then levelled with a hot air knife. This prevents the copper pads from oxidising makes it easier to solder.

Thru-Plated Holes

All holes are plated with copper then treated with the lead Free HASL pad treatment. This increases the surface area for the solder and capillary action improves solderability. The end result is a stronger more reliable connection.

Quality FR4 Board Material

We use quality FR4 fibreglass board material unlike the paper based phenolic material that is found in many prototyping boards. Fibreglass reinforced substrates have a much higher strength that paper reinforced boards and are more resistant to cracking or breaking.

Solder Mask/Resist

The FR4 material is usually a light grey/green colour. A red lacquer-like layer is applied using a silk screen but this isn’t just about making the board look good.

For the non-solderable copper tracks the solder resist helps to prevent oxidation. The solder resist also help prevent bridging between 2 adjoining pads.