In order to make the WearWare: G-Force Data Logger as small as possible, home etching or milling was out of the question. I’ve wanted to have my own PCBs made by a fab house for quite a while, and although I have used Spirit Circuits Go-Naked service to make two layer PCBs before, they don’t come with a solder mask or silkscreen.
I’ve looked at services such as Fusion PCB, Gold Phoenix and OSH Park in the past but never took the plunge before. To aid in the development of the WearWare: G-Force data logger it was decided that a ‘development platform’, with just a PIC, support circuitry and some I/O headers was needed!
And so Test1 was born. This simple 2 layer PCB contains the same PIC16(L)F1454 that the integrated data logger will use. The aim was to develop a USB device that could be expanded into different functions by simply changing the plugin module. On the 6th January 2014 I sent of my design, and 17 days later here are the results:
In all of the excitement of getting a design sent of to be made (For a non work purpose might I add!) I have inadvertently sent the wrong design file off! The only difference between this and the correct version is the inclusion of a 10uf capacitor for the vbus3v3 connection. This isn’t a problem if you are just using the PIC as a general purpose processor, but does mean you are unable to use it with USB until you have added the capacitor…
I was really happy with the support that the team at OSH Park have given me so far, I was having difficulties with getting one of my layers to render on their servers and they provided a fix very quickly!
I would highly recommend using them if you have a prototype board or two to make.
Another of the reasons for getting a board fabricated was to allow me to use the hot plate solder paste method, in which you heat the PCB from the underside with solder past and components on the top. The reason for this is the solder mask which stops the solder past flowing where it really shouldn’t.
To round this up the first version of the WearWare: G-Force Data Logger (Version 0.1) has been sent off, and at a whopping 22x22mm in size, will be even smaller than this!