Timezone clocks
| Projects | |
|---|---|
| Participants | Katje |
| Skills | Electronics, PCB design, Programming, Networking, TCP/IP, NTP. |
| Status | Active |
| Niche | Electronics |
| Purpose | Fun |
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/New York - EST (UTC-5:00) / EDT (UTC-4:00)
- London - UTC / BST (UTC+1:00)
- Amsterdam - CET (UTC+1:00) / CEST (UTC+2:00)
- Baikonur - (UTC+6:00)
- Sydney - AEST (UTC+10:00) / EDST (UTC+11:00)
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?
Which timezones could be a long debate, if we're not careful we could end up with 24+ clocks on the wall. Increasing to 7 clocks would allow inclusion of SF and Seoul. Downside is each clock is going to cost about €20, plus prototyping costs.
Alternative timezones:
- Vandenberg - PST (UTC-8:00 / PDT (UTC-7:00)
- Cape Canaveral - EST (UTC-5:00) / EDT (UTC-4:00)
- STATION/GMT
- Amsterdam - CET (UTC+1:00) / CEST (UTC+2:00)
- Baikanur - (UTC+6:00)
- Tanegashima - JST (UTC+9:00)
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.
Prototype Parts
- 0.56" 7 Segment Displays - ORDERED, DESPATCHED, DELIVERED (Aliexpress)
- 74HC137 - To order (EOO)
- 74HC4511 BCD-7 Segment Driver - ORDERED, Awaiting Dispatch (Aliexpress)
- Resisters - Stock item in the space
- Breadboards - Stock item
- ESP8266 - ORDERED, DESPATCHED, DELIVERED (Ebay)
- DS3231 RTC Module - ORDERED, DESPATCHED, DELIVERED(Aliexpress)
Final Design parts
- 57mm Common Cathode 7 Segment LED Display (6-4 per clock)
Sponsor a Clock
An idea has been suggested that members of the space may want to sponsor a clock (speed of project is going to be dictated by availability of funds). The cost of a single finished clock will be about €20 per clock, depending on exchange rate and whether it works first time...
Sponsors so far:
- Bigmacfoobar
- Katje
- Redlizard
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.