Well Don, I got side tracked by a million other jobs but I got there in the end. I have the timer working and boxed up. Hope you like the photos.
I designed the pcb and got it made in China (10 of them for $11 delivered). I decided to use a transformer with two 9V secondary's, that way I could provide a separate supply for the relay board and the arduino circuit keeping them totally isolated. The components on the board are just rectifiers, voltage regs and smoothing capacitors for the two supplies.
I bought a red lcd for the display but unfortunately it didn't seem to work, so just a regular one in for now until I get another.
I didn't want to chop plugs off my Durst enlarger so fitted a euro style 2 pin socket on the back of the box, that way my enlarger cables stay original.
Ralph
life just ain't that simple anymore.I don't care about all that. Just one friend doing something for another.
life just ain't that simple anymore.
That's a different design then this, of course. Although a fine project, the user interface seemed a bit overly complex to me when I went looking for plans to build up an f.stop timer. I ran across the Arduino project on the previously-mentioned Italian web site, which had a simplified feature set while still supporting basic enlarger timer focus/countdown/count-up functions as well as dodge/burn function and f/stop increments/decrements from an entered base-time, which is all I really required.Another member on the forum, polyglot, created one as well. Here is a link to his project. I bought a PCB from him and all of the components to make one. Life got in the way and I never finished it. This project makes me want to move forward with an f-stop timer!
That is very convenient! I installed a cheap Chinese 433mhz kit for this purpose. I'm glad I did! It's fascinating how annoying walking from one side of the darkroom to the other gets while printing, just to flip the light switch.I might also tie this into my room light switches, which are also arduino controlled via radio signals
I've actually designed that walk into darkrooms - turning on the light in a darkroom isn't something you want to do without having to think about it.That is very convenient! I installed a cheap Chinese 433mhz kit for this purpose. I'm glad I did! It's fascinating how annoying walking from one side of the darkroom to the other gets while printing, just to flip the light switch.
It's quite trivial to use 3 rotary encoders for this. Although it's overkill IMO. I recently built a development clock/timer that uses a single rotary encoder to set times from 1 second up to 99 minutes 59 seconds. I programmed it in such a way that the faster you turn the encoder, the faster the numbers change. This makes it easy to quickly to go from something like 1 minute to 15 minutes, and it's very intuitive to use.
Nobody's stopping you from doing something similar!
Looks like a neat little project, and I might have to build one for myself and play around with different interface designs.
- And for a physical device, designing a solid and reliable interface is always a 'fun challenge' while trying to balance cost vs usability.
I'm curious as to what you used to filter your screen, and how well that has worked for you.
I've actually designed that walk into darkrooms - turning on the light in a darkroom isn't something you want to do without having to think about it.
Of course, that was for shared darkrooms.
For room lights, my favourite is a pull chain from a ceiling fixture.
Help!!! I have fallen and I can't get up.
I breadboard with a nano board, got that to work. I transferred onto a PCB........... Keypad works fine. Function switch works fine, I see things changing on the LCD.
HELP the start switch does nothing, D 11 does not change state. The only thing I see is the "L" LED goes from on to off.
In standby mode (waiting for me to do something)
Start switch in the off position shows 1.75VDC between D13 and GND, goes to "0" when I press start. D11 going to the relays does not change sitting at 4.4VDC.
D12 to GND sits at 4.4VDC and drops to "0" when I press the function button.
I have checked continuity and cross continuity on everything all checks good. I have used power from the computers USB and a plug in phone charger, I get the same.
I have already re-soldered the LCD to the PCB, no change.
Can someone point me in the right direction.
Thanks
Carlos
Help!!! I have fallen and I can't get up.
I breadboard with a nano board, got that to work. I transferred onto a PCB........... Keypad works fine. Function switch works fine, I see things changing on the LCD.
HELP the start switch does nothing, D 11 does not change state. The only thing I see is the "L" LED goes from on to off.
In standby mode (waiting for me to do something)
Start switch in the off position shows 1.75VDC between D13 and GND, goes to "0" when I press start. D11 going to the relays does not change sitting at 4.4VDC.
D12 to GND sits at 4.4VDC and drops to "0" when I press the function button.
I have checked continuity and cross continuity on everything all checks good. I have used power from the computers USB and a plug in phone charger, I get the same.
I have already re-soldered the LCD to the PCB, no change.
Can someone point me in the right direction.
Thanks
Carlos
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?