Timezone clocks
| Projects | |
|---|---|
| Participants | Katje |
| Skills | Electronics, PCB design, Programming, Networking, TCP/IP, NTP. |
| Status | Planning |
| Niche | Electronics |
| Purpose | Fun |
Contents
Intro
I thought it would be a fun idea to have some clocks above the entrance way between the main space, and the aux space.
Feature wish list:
- NTP based time, so as to avoid need to change clocks to keep time or for DST.
- LED based displays (Easy to use/see)
- 24 hour clock.
- KISS design that doesn't solely rely on funky code to work.
Basic design thoughts
74HC4543 driver chip, this allows latching of input so all 4 or 6 digits needs just 4 data pins, and 1 pin per digit for latching.
Design questions?
4 digits or 6?
Having 5 clocks with seconds displayed where sink may not be spot on perfect could really jar. Maybe have a 6 digit version for local time, with 4 digit display for the others?
45mm or 56mm ?
Which micro?
Arduino pro mini is cheap, small and should have enough grunt, but could be an interesting challenge getting TCP/IP, NTP, Timezones, DST, and clock functionality all in 2k of ram.
Techwolf12: ESP8266-12 is very cheap (around 6 euro), is programmable by Arduino and has buildin Wifi.
Wired or wifi?
We'll need wires to power it, so ethernet + PoE may be the simplest solution?
Techwolf12: When using the ESP, you will need 3.3v.
Timezones
Which timezones to use?
- Boston
- London
- Amsterdam
- Moscow
- Sydney
Bigmac says: I deal with San Francisco, Johannesburg and Manila, can we have those too please? And New York instead of Boston? And Seoul or Tokyo for completeness?
Design
Have created an initial draft idea for a design. Schematic: File:LEDClock-sch.pdf
It's based on a 74hc137 3 to 8 multiplexer, and a 74hc4511 BCD to 7 segment decoder. Will test proof of concept with 0.56" displays.
Status
2017-03-16
Schematic design complete, parts ordered to produce prototype. Prototype PCB for 4 digit version based on 0.56" displays designed. Courage still needed to hit the order button...
2017-03-02
Crazy idea discussed on the mailing list.
