I seem to have got a little fixated on clocks over the last couple of months, but rather than go down a simple route I have tried to use parts I already had ‘in-stock’. For example this picture is of a binary clocking using some phosphor neon’s I had in a draw rather than led’s to indicated the time, but more of that later in the post.
My first lockdown clock build on the face of it is just a simple digital clock but rather than use a display with the driver built in I got the 8266 to do everything. Then to really mess things up I used a 8266 with not quite enough IO so added PIC programmed to act like a 2 to 4 line decoder for the digit selection. Then as the analog input line was still spare I added auto brightness control. The 8266 connects to the internet once a day to correct any time drift. The only cheat is the flashing colon, with no IO to left this it’s driven from a simple 2 transistor flip-flop.
Next back to green phosphor neon’s, I was having a bit of play with them to understand potential driver circuits for a nixie clock I am planning when I had the idea they would make a good indicators for a binary clock … This would also be an opportunity develop the clock elements for the planned nixie clock as the nixie tubes themselves were still on their way from Eastern Europe !
Again looking around for bits I had immediately available I landed on developing a ‘re-usable’ clock source design using an ESP01, building on the s/w I had used for the earlier digital clock. This outputs the ‘time’ once a second via the ESP01’s serial port as a simple text string. A bit of added complexity was to correct for summertime, again it is updated from an a NPT server once a day or manually via a push button. The serial time feed is read into a second micro-controller that sorts out the binary display. For this I used a Piksey Pico Arduino compatible uP that I had got a while before from a Kickstarter. These have the advantage of being smaller than a Nano but still have slightly more accessible IO.
In the process of testing the clock I did mange to destroy an ESP01 – they really do not run for long on 12V and one Piksey ( a lose wire touched the 115Vdc rail !), but you can see the finished results below. I think the indicators are a really pleasing green much more subtle that using these newfangled led things….
The video shows the start up sequence with the uppermost orange neon flashing until the wifi connects then you see the whole display update as the Piksey starts to get updates from the ESP.
The next plan is to put it in some form of display case to avoid accidental electric shocks !