The blind's man clock

RE: The blind's man clock

jc2048 — Fri, 20 Apr 2018 21:28:52 GMT

A further solution to setting the time that you might add to your list is reception of a radio time signal.

Here's some information on the one that covers the UK (it used to be called 'Rugby time' until they moved the transmitter site):

http://www.npl.co.uk/science-technology/time-frequency/products-and-services/time/msf-radio-time-signal

It's very accurate as it comes from an atomic clock that is synchronised to the national time standard. It has the advantage that your clock could set itself and you then don't need a manual way to do that. It also automatically handles the changes from summer time to GMT.

Other countries have similar transmissions. There's a higher powered station in Germany that covers most of Europe. I don't know about the US - they certainly used to have one. Note that the carrier frequencies and the form of modulation and coding of the data are different, so you need a receiver board that's specific to the one you want to receive.

If you took this approach, you'd also need a RTC as a backup as they take the transmitter off air a couple of times a year for maintenance.

RE: The blind's man clock

jw0752 — Thu, 19 Apr 2018 19:30:42 GMT

Hi Idan,

This will be a great project and it will solve a real world problem. I really like some of the suggestions made in the comments and I bet you can incorporate one or two of them.

John

RE: The blind's man clock

balearicdynamics — Tue, 17 Apr 2018 19:43:45 GMT

Sounds very good. As you can see correct colors, why not a version based - instead of an RGB LED - with Nexopixel? A small 8 LEDs array is cheap, light is more readable and better quality and it can be drawn easily and efficiently with Arduino.

Enrico

RE: The blind's man clock

jc2048 — Tue, 17 Apr 2018 17:21:34 GMT

That's a nice idea. I think, for night-time use, you might want to diffuse the light a bit - you don't want to be looking at an intense point (and it's much easier to determine subtle variations in colour if the light is spread). Maybe project the light onto a white surface or through something translucent.

I wondered what I'd choose for the colours (if it were mine) and decided I'd have two patches of colour and use the resistor colour code - the black would be a bit of a nuisance, though; we still seem to be waiting for someone to invent the LED that emits black light.

RE: The blind's man clock

mcb1 — Tue, 17 Apr 2018 15:09:04 GMT

A unique solution.

Knowing me, I'd forget what colour was what ... but I like the sunset/sunrise thing.

You'll want to add an RTC for longer term accuracy.

I seem to recall they did a coloured arrangement on a large skyscaper in Hong Kong?? years ago.

They used some form of lighting that allowed easy identification of the time down to 1/4 hour.

I can't find any info about it, and I'm sure my mind isn't playing tricks.

Mark

RE: The blind's man clock

genebren — Tue, 17 Apr 2018 14:19:07 GMT

Nice solution to the problem of not being able to see the digits on a clock. I have used LED colors to show data on small projects, but sometimes it is difficult do distinguish yellow from orange and other close color combinations. Some times it is easier to simply flash alternating pairs of colors, like red-yellow as opposed to the mixed color (orange).

Gene