Since I found out about the low-power PIC18LF2550, development of my FXO project took off. I sat quite a few hours to correct my schematic and then fix a PCB that I had already semi-prepared. Here, then, is the latest schematic:
You can click on the above image to get a more readable view. You cannot miss the big “UNTESTED” seal on the schematic. This is just to give a warning that the circuit has not yet been tested and thus I do not advise anyone to try it out. And here are the top and the bottom PCB views, both with the same warning:
So, my next steps were to export my BOM and to order the materials (I used Mouser, since I could not find any other store selling Silabs chips on retail). In the next few days I will also place an order for the prototype PCBs and when I get back home from holidays (yes, I am typing this post while on holidays), I will start with assembling my first three prototypes.
So, isn’t Open USB FXO a really fast-growing baby? I just hope it’s not too fast, that is, that I have not made any big mistakes in my haste. But what is prototyping for, if not for finding out exactly this? Reality will show anyway. So, I am leaving this post as it is now and getting back into exporting my Eagle files in Gerber format and ordering my PCBs. Updates may follow later on. Good luck!