Anyone who has ever processed real analog film in a darkroom probably remembers two things: the awkward fumbling in absolute darkness while trying to get the film loaded into the developing reel, and the tedium of getting the timing for each solution just right. This automatic film-developing machine can’t help much with the former, but it more than makes up for that by taking care of the latter.

For those who haven’t experienced the pleasures of the darkroom — and we mean that sincerely; watching images appear before your eyes is straight magic — film processing is divided into two phases: developing the exposed film from the camera, and making prints from the film. [kauzerei]’s machine automates development and centers around a modified developing tank and a set of vessels for the various solutions needed for different film processes. Pumps and solenoid valves control the flow of solutions in and out of the developing tank, while a servo mounted on the tank’s cover gently rotates the reel to keep the film exposed to fresh solutions; proper agitation is the secret sauce of film developing.

The developing machine has a lot of other nice features that really should help with getting consistent results. The developing tank sits on a strain gauge, to ensure the proper amount of each solution is added. To avoid splotches that can come from using plain tap water, rinse water is filtered using a household drinking water pitcher. The entire rig can be submerged in a heated water bath for a consistent temperature during processing. And, with four solution reservoirs, the machine is adaptable to multiple processes. [kauzerei] lists black and white and C41 color negative processes, but we’d imagine it would be easy to support a color slide process like E6 too.

This looks like a great build, and while it’s not the first darkroom bot we’ve seen — we even featured one made from Lego Technics once upon a time — this one has us itching to get back into the darkroom again.

Usually, when we are talking about homebrew around here, we mean building your own equipment. However, most other people probably mean brewing beer, something that’s become increasingly popular as one goes from microbreweries to home kitchen breweries. People have been making beer for centuries so you can imagine it doesn’t take sophisticated equipment, but a little automation can go a long way to making it easier. When [LeapingLamb] made a batch using only a cooler, a stock pot, and a propane burner, he knew he had to do something better. That’s how Brew|LOGIC was born.

There are many ways to make beer, but Brew|LOGIC focuses on a single vessel process and [LeapingLamb] mentions that the system is akin to a sous vide cooker, keeping the contents of the pot at a specific temperature.

Honestly, though, we think he’s selling himself a bit short. The system has a remote application for control and is well-constructed. This isn’t just a temperature controller thrown into a pot. There’s also a pump for recirculation.

The common stock pot gets some serious modifications to hold the heating element and temperature probe. It also gets some spring-loaded clamps to hold the lid down. Expect to do a lot of drilling.

The electronics uses an Arduino, a Bluetooth board, and some relays (including a solid state relay). The finished system can brew between 5 and 15 gallons of beer at a time. While the system seems pretty good to us, he did list some ideas he has for future expansion, including valves, sensors for water level and specific gravity, and some software changes.

After reading that the system was similar to a sous vide cooker, we wondered if you could use a standard one. Turns out, you can. If you want to make better beer without electronic hacking, there’s always the genetic kind.

If your idea of a six-course meal is a small order of chicken nuggets, you might have missed the rise of sous vide among cooks. The idea is you seal food in a plastic pouch and then cook it in a water bath that is held at a precise temperature. That temperature is much lower than you usually use, so the cook times are long, but the result is food that is evenly cooked and does not lose much moisture during the cooking process. Of course, controlling a temperature is a perfect job for a microcontroller and [Kasperkors] has made his own setup using an Arduino for control. The post is in Danish, but Google translate is frighteningly good.

The attractive setup uses an Arduino Mega, a display, a waterproof temperature probe, and some odds and ends. The translation does fall down a little on the parts list, but if you substitute “ground” for “earth” and “soil” you should be safe. For the true epicurean, form is as important as function, and [Kasperkors’] acrylic box with LEDs within is certainly eye-catching. You can see a video of the device, below.

The switches, LEDs, and relays are all pretty standard fare. The real heart of the project is the temperature control. Many controllers use a PID (proportional/integral/derivative) to hold the temperature, but this project takes a more pragmatic approach. Depending on how far from the set point the temperature is, the controller simply drives the heating element differently and measures more or less frequently to adjust. For example, if the temperature is more than two degrees low, the heating element is left on constantly. As it gets closer, though, the heating element runs for 10 seconds, there’s a 5 second wait, and then the algorithm reads the temperature again.

There’s a lot of debate about how precise the temperature has to be. Apparently, for things like fish, a wide range of temperatures isn’t a problem. Eggs, however, need tighter control because their proteins can denature (whatever that means).

There’s also a safety relay that shuts the whole affair down if the temperature goes very high or low so a bad temperature sensor won’t boil everything away. We might have considered doing that with a bimetallic coil so that even an Arduino failure would not stop it from working.

We’ve seen other attractive sous vide setups. Not to mention the more utilitarian builds made with a crock pot. No matter what it looks like, these projects are probably not going to help your waistline.