The Toadstool

A second batch of PCBs arrived from China a couple of weeks ago, and I've had a chance to assemble and test them. Apart from a few minor cosmetics on the silkscreen, I'm happy with the outcome - the gallery has been updated with latest images.

What changed:

• Toadstool CAP headers changed to provide better stability
• Broke out the Reset pin into the Toadstool CAP header
  
• Low-profile SMD reset button, so it can be pressed with a Toadstool Cap mounted
• Aluminium caps now replace the tantalum ones
• Silkscreen and layout tweaks

Where to from here?

I'm testing the range of Toadstool CAPs that arrived in the same shipment:

• an EEPROM module based on the Microchip 24LC128
• a RTC using in the Microchip MCP79400
• a USB-Serial converter using the Microchip MCP2200 (having a bit of trouble with this one!)

The ATmega328P prototype of the Toadstool arrived a month ago and has been through some solid testing. Here it is assembled:

I found a couple of usability issues with the physical layout which I've corrected:

• The 2x6 header for the "Toadstool Caps" (breakout boards) has been split into two 1x6 headers to add stability to the Cap
• The reset switch has been switched (!) for an SMD low profile version to prevent the Toadstool Cap from obscuring it.
• The Tantalum caps have been replaced by Aluminium ones to make the board more reflow friendly (listen to this great podcast on capacitors)
• A number of changes to silkscreen to make it more readable