So, I'm early in the learning curve on all things Arduino. Using an Uno, I recreated a door lock with a servo that throws the bolt with an rf remote. In an effort to shrink things, I moved it over to a nano and it's all sitting there on the breadboard waiting for me to make the next move.
I would actually like to continue the process and figure out the best way to package this all up and actually mount it on a barn door that could use it. I've done a bit of looking, but I don't seem to find much in the way of how to work through this next phase of these projects. I would need to move the components from breadboard to a more permanent mounting and interconnection system and then enclose it all in a weatherproof package.
Does anyone have any guidance on this or some links to processes and projects where this is fairly well laid out?
Thanks in advance.
The minimum amount of changes can be achieved by using a "Perma Proto" board. This is a grid-of-holes type prototype board laid out with connections like a breadboard. I do not recommend this.
You should be able to find a prototype board that fits a Nano. They are a bit more difficult to find than R3-sized shields. That should be one of the quickest ways to make it permanently soldered.
Custom-made circuit boards are so cheap now that I go straight from breadboard to surface-mount PCB. The quality available for just a few bucks per square inch is really amazing and you don't need a lot of square inches for most Arduino projects.
What are your soldering skills?
You could make a simple permanent project with stripboard (veroboard) and an Atmega 328 microprocessor. If you use the internal 8MHz oscillator only three external 0.1µF capacitors and a pullup resitor for RESET are required.
If the project is simple and you want to save £1 by using a cheaper MCU then an Attiny84 might be sufficient. The -84 is also a good bit smaller than a -328 if that matters.
Just to be clear, I’m not worried about using the nano for permanent deployment. I actually got this working on an uno but bought the nano for it’s smaller size. I’ve since learned there are some really small ones for simple tasks like this.
Attached are a couple of pictures showing both states: locked and unlocked.
I still have to work out the power as the nano is powered by the usb. the 9v is powering the servo. Ideally, I’ll have a transformer powering the whole thing with the battery as backup to minimize lockout.
My soldering skill are ok. It may not be the prettiest job, but I can get it done. I appreciate the info thus far.
the 9v is powering the servo.
Most servos are designed for 4.8v to 6v. If so, 9v will damage it. I guess the PP3 style battery is too puny to produce enough current to cause damage. And it will run flat very quickly.
You need a very reliable power source so you can be sure that you can always open the lock.
So, after a bit more searching, I think I need one of these:
and then mount it in a plastic box. I think this will allow for a cleaner, deployable solution.
I would work backwards.
go on e-bay or your favorite seller
find an enclosure you like, lots of (claimed to be) waterproof versions. be careful of the waterproof ones that have large holes.
find the inside dimensions and draw that on a paper. place your Nano on that
figure how it would sit. if you need a larger or smaller enclosure, you can do that with a simple search.
the boards that were discussed, perf board, come in fiberglass and paper.
single and double sided.
the brown paper, single sides are by far easier to work with as far as cutting goes
the double sided fiberglass IMHO, are better because you have two sides for solder.
Then there are perf boards. every hole is an island.
Strip board, every row is a connected to eliminate many jumper wires
RadioShack used to sell multipurpose boards that fix exactly into their enclosures and had short strips to extend the pins of an IC.
Bottom line is that for a few dollars, some paper boards can be had, cut and fit into a box. Held in place with some hot glue.
the enclosure can have LEDs, clear lid, display, etc.
and you can even stack two boards in to get more space for more things.
For power supply you can use 3xAA batteries or a 5V USB supply. That would work for both the Arduino and the servo.
Solder the whole thing on perfboard or stripboard.
If you want to go "really small" you're probably looking at the ATtiny processors. An ATtiny85 (or 45 or even 25) would probably do fine for this project indeed. Just requires a capacitor and resistor to work. Use the internal 8 MHz resonator, fast enough. Hard to make it smaller than that.
Waterproof boxes with holes in the bottom work great to protect your electronics - for projects that are powered on and thus producing a bit of heat at all times, keeping the inside temperature 1°C or so higher than ambient is enough.