The new prototype PCBs just arrived from OSHPark – great quality as usual.
I noticed that there are only few things that I may change before call it official: slightly move some components around so they fit better and become easier to solder; add one jumper for switch on/off the optional button cell battery on the bottom of the board; make some pads and holes larger; … and few other things.
I have finally managed to finish the first version of the schematics and PCB‘s and to order the first 3 pieces. This work is based on some previous experiments and designs.
The schematics is nothing special – it is the well known minimal configuration for the ATtiny plus just few addition components – some of them optional.
The required components are the 2 capacitors between Vcc/GND and the 10K resistor on the RESET wire.
There is RESET push-button connected to the micro-controller.
The micro-controller connects to the outside world through 2 headers – H1 an H2. They are in two different sizes for number of rasons: first – to have more connections available for wires, and second – to make sure we won’t mistake H1 and H2.
Next to the headers there is 1×2 connector for external power source.
There is an optional battery for application where built-in power source is needed.
The PCB is a fork of my previous work on a simple header board.
There are 4 holes in the corners in case the board should be fixed to another object.
On each side of the IC there are 2-row headers – on 2×4 and the other 2×5.
External power source connector is put along with the H2 header.
The ISP connector is at the top of the board. Between it and the rest of the board there is 1×6 header-like probe – this could be used for testing as well as for easier cutting off the ISP part of the board in case is not (or no longer) needed.
The pads for the optional battery are on the bottom.