Micro NumiTron clock

The boards have been sent to fab as of Thursday night, using OSHpark.

I need to source a suitable battery with close to 1"^2 dimensions as I don't want a bulky battery sticking up out of the top of the clock.

Due to size constraints and limited space, I have switched from a DS1307 to a DS1337 the difference is size and the fact that the DS1337 does not have a dedicated battery backup, thus the small super cap and voltage switching circuit on the back of the board.

All parts can be ordered via digi-key minus the numitron tubes. If there is any interest I will make a few clocks for sale once everything is stable in its new form factor.

I'll update again soon.

I was able to get some time in tonight on laying out the schematics and a rough placement of parts on the board. The Numitron tube will site vertical as well as the PCB, have to figure out a way to make a stand for it. The numitron tube is not modeled in the renders, as I do not use 3d software i don't have any models or step files of IV-9 Numitron tubes.

If anyone knows where I may find one please let me know.

A render of the front of the clock board, the numitron will connect to the header on the bottom of the board.

The back of the board, sports the mico usb connection, lipo charger, and lipo connection. The left over space is just big enough for a 110mAh lipo cell. This is going to require learning about the power management of the Atmega line, which I have been meaning to do for quite some time. Also the USB power is Diode OR'ed with the Lipo so if the user is powering via the usb the lipo will charge but the system will use its power form USB.

The board is not fully routed yet thus the yellow air wires, Units are in MM. I am looking to have then sent to OSHpark before the end of the week. I will also update the parts list as some of the parts have changed.

Thus far this board needs to fit on a 1"x1" area, designing a board like this will not be DIY friendly unless you have the required equipment or the patients to place 0402 parts and QFN type parts.

currently this projects main micro will be an Atmel ATMega 168, with 16KB oh program memory. I already have the core of the code finished. I was able to port alot of it over from another clock project I was working on. None of the serial terminal menu was ported over, as just the core takes around 8KB of program space. I may find a way to condense this later.

I have also started the schematics and layout of the board, waiting for my EDA software to update before I can lay down any more parts. (I haven't updated in a while.)

Ill post more later. I should have the boards out to fab by the end of the week.