PROJECT BRIEF - Countdown Timer

Thread Starter

capturefilms

Joined Nov 19, 2019
13
Hello,

I am looking for someone to build a countdown timer. It is to be used as a prop in a film.

I don't need the housing, just the electronic components, I have no experience with this kind of thing, so I am looking to commission someone to make it.

I need three components, that are programmable , hours (3 digits), mins (2 digits), seconds (2 digits), (see attached still). I do not need the wording of Hours, mins, Secs to be made, these will be part of the housing.

I have seen single, double and treble digit LED units (see attached still) and was hoping they could be made from something like this.

It will be placed in a custom housing, approximately 2.5 inches x 6 inches. any wires/components/power supplies can be easily hidden.

If anyone would like the challenge of building it or can point in me in the direction of someone than can that would be very much appropriated.

Many thanks in advance
 

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JohnInTX

Joined Jun 26, 2012
3,825
Be aware that if the display is multiplexed you can have have strobing in the image when you film it unless the refresh rate is considerably higher than the frame rate.
 

Yaakov

Joined Jan 27, 2019
1,604
Well, it's not a particularly difficult project so perhaps someone will want to take it on. It will still be costly if you want to done right as a one off.
 

JohnInTX

Joined Jun 26, 2012
3,825
A good choice for a display would be something like LTM-8522. These are old but still available. They use a simple serial input to drive the segments directly, no multiplexing. You could daisy chain 3 x 3 digit units and just mask off the two unused ones.
 

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Thread Starter

capturefilms

Joined Nov 19, 2019
13
A good choice for a display would be something like LTM-8522. These are old but still available. They use a simple serial input to drive the segments directly, no multiplexing. You could daisy chain 3 x 3 digit units and just mask off the two unused ones.
Thanks john, but this is a foreign language to me, I wouldn't know where to start. I'm hoping to find someone that I can work with to build it for me from scratch
 

dl324

Joined Mar 30, 2015
9,154
If anyone would like the challenge of building it or can point in me in the direction of someone than can that would be very much appropriated.
What are your constraints on solution space? Personally, I'd probably use an Arduino Uno for something like that.

Just keep the multiplex rate high enough that you won't see flicker when it's filmed. Maybe 1kHz or so.
 

Thread Starter

capturefilms

Joined Nov 19, 2019
13
What are your constraints on solution space? Personally, I'd probably use an Arduino Uno for something like that.

Just keep the multiplex rate high enough that you won't see flicker when it's filmed. Maybe 1kHz or so.
Sorry mate, I have no idea what this means. As I said, I'm hoping to find someone that could build it for me.
 

Bernard

Joined Aug 7, 2008
5,291
What power is available, AC 50 HZ, 60 HZ DC ?
Where are you?
Are you supplying the display ? How is the initial time delivered ?
 

dl324

Joined Mar 30, 2015
9,154
Sorry mate, I have no idea what this means. As I said, I'm hoping to find someone that could build it for me.
Hate to be the one to burst your bubble, no one here works for free. We give free assistance as a community service, but we don't work for free.
 

Thread Starter

capturefilms

Joined Nov 19, 2019
13
What power is available, AC 50 HZ, 60 HZ DC ?
Where are you?
Are you supplying the display ?
I can supply any power required to the unit. The car will be static whilst being filmed.
I'm in the UK.
I will buy all the necessary components and ship them wherever needed.
 

Thread Starter

capturefilms

Joined Nov 19, 2019
13
Hate to be the one to burst your bubble, no one here works for free. We give free assistance as a community service, but we don't work for free.
I haven't asked anyone to work for free. if you read my post again....you'll see that a) I'm offering to commission someone to make the project and b) I know nothing about this stuff.

That's why I'm here. Cheers.
 

dl324

Joined Mar 30, 2015
9,154
I haven't asked anyone to work for free. if you read my post again....you'll see that a) I'm offering to commission someone to make the project and b) I know nothing about this stuff.

That's why I'm here. Cheers.
When an engineer designs a product, they assume responsibility for product liability. I wouldn't do piece work for less than $10,000 plus a per diem rate of $2000.

I'll help you design it for free...
 

Thread Starter

capturefilms

Joined Nov 19, 2019
13
When an engineer designs a product, they assume responsibility for product liability. I wouldn't do piece work for less than $10,000 plus a per diem rate of $2000.

I'll help you design it for free...
I don't understand. Are you offering to help design it for free, but you want $2,000 a day to build it?
 

Bernard

Joined Aug 7, 2008
5,291
How is the initial time delivered, or is it just a random number ?
I made a digital clock in 1972 with TTL logic but that was 47 years ago & I hate shipping overseas.
 

Thread Starter

capturefilms

Joined Nov 19, 2019
13
How is the initial time delivered, or is it just a random number ?
I made a digital clock in 1972 with TTL logic but that was 47 years ago & I hate shipping overseas.
It shows different times of a 7 days countdown, which we must be able to programme into the timer.
 

dl324

Joined Mar 30, 2015
9,154
I don't understand. Are you offering to help design it for free, but you want $2,000 a day to build it?
Yes. If I help you design it, I have no product liability responsibility and I can walk away from it at any time. I don't have to take your written and spoken requirements and turn that in to a specification for what you really want.

Could probably bang out the Arduino code in less than a day and design the hardware in a few hours (at most). If I designed it, I need to spend time understanding your requirements, writing a project proposal, having it approved by my attorney, and iterate until the spec is correct. Then I need to design and build according to your schedule. Even if you want to build it, I'd need to build it myself first to make sure it met specifications.

I found some displays here, but none are exactly what you want and they're all bigger than 2.5"x6".
 
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