The Moment Of Truth - Nixie Clock ITS1A Manual

ITS1A CLOCK
comfortable with to do this. Make sure the chip is oriented correctly! The notch should be next to the
1x20 socket that the display board plugs in to – it is circled in the next picture.
Insert the ESP-01. Either solder it in place or insert it into the socket you soldered earlier.
Insert the display board into the socket on the main board. Bolt it in place.
Check the resistance between ground and the bottom pin of one of the tubes – this is the anode 2 pin –
it should be around 470k.

The Moment of Truth

Insert the USB lead into the socket on the main board, insert the other end into a USB adapter. If you
see smoke, unplug it!
The red LED on the ESP-01 should come on (if it has one, there are several variations of the ESP-01).
After a few moments, the tubes should display all ones. Then it will start counting up – with each tube
one ahead of the tube to its left. This is intended to test that all of the segments light up and extinguish
properly. In addition, the colon leds should blink on and off.
If not all segments light, or some segments stay lit when they shouldn't don't panic. First of all, leave it
running for a few minutes to see if it fixes itself. In fact, the datasheet recommends that if the tubes
haven't been used for a month or more, you should run them for at least 10 minutes. They have
probably been unused for a lot longer than 1 month!
The -250V line is the key one that affects segment brightness and whether they come on or not. It can
sometimes take a few minutes to stabilize, and it can take the tubes a little while to warm up. Chances
are that any unlit segments will come on after a few minutes, provided the digits are changing – for
example when the date is displayed. If they still don't come on after 10 minutes, check the -250V line –
it needs to be at least -235V.
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