New kit in store: simple clock with HDSP-2534 display

Update July 31, 2020: See the latest revision here.

The centerpiece of this clock kit is the vintage-style 8-character display HDSP-2534 originally from HP, currently manufactured by Avago. The assembled clock looks like in the photo below. The dock, not included in the kit, is a miniB USB phone charger; it can be easily sourced from ebay, if you don't already have one. (You can even get a fancy one, e.g. custom-made exotic wood, on etsy.com.)

The kit includes the following components:

• PCB;
• ATmega328P, with bootloader and fuses for 8MHz internal clock, and the sketch preloaded (also downloadable from here);
• HDSP-2534 display;
• 595 shift register;
• DS1307 real time clock;
• 32kHz crystal
• CR1220 battery;
• battery holder;
• push buttons (x2);
• capacitor 100nF (x3);
• 10k resistor (x3);
• 28-pin socket;
• 16-pin socket;
• 8-pin socket;
• 6-pin machined female header (x4).

   $40, free shipping to North America

Note: The kit is currently out of stock. Please send me an email (my address is in the top right corner of the page) if you want one. I will put together only a small number of kits at this price, since the display itself is sold by digikey for about $40.

Schematic and board layout are shown below. Preliminary Eagle files can be found here.

The kit is super easy to assemble. It is really impossible to misplace components on the board.

Still, here is some advice:

• pay attention to the orientation of each of the three integrated circuits, when you insert them in their respective sockets;
• before soldering the battery holder, put some solder on the big center pad;
• avoid solder bridges between the USB miniB connector's terminals by wetting their pads (on the bottom side) with a flux pen;
• it is recommended, for aesthetic purpose, not to solder the FTDI connector to the board; if you need to upgrade the existing software (download from here), you can just hold the 6-pin make header tightly in place while uploading the sketch;