automation

180 Articles

Testing Hundreds Of Used LFP Cells Requires Some Automation

August 4, 2026 by 7 Comments

Although Li-ion cells have become a lot cheaper over the years, if you wish to buy hundreds of high-quality ones for that performance go-kart project, you may feel financially pressured into going for the option of stripping down years-old commercial battery packs instead.

While this is a financially sound option, you do have to figure out what the condition is of each cell before you happily stuff them into a new battery pack for said go-kart, as [Within Tolerance] recently did.

This is something that can be done manually, but for the 768 lithium iron phosphate (LFP) cells that were obtained for this project that’d be quite the tedious task. Hence it was decided to instead spend that time designing a system to automate this process, capable of charging, discharging, measuring and quantifying individual cells.

You can find the resulting Cell Goblin battery tester project on GitHub, which entails a custom PCB featuring an ESP32-S2 as the brains and associated software to monitor the process on a connected PC. Fortunately the issues on the PCB that are described in the video are claimed to be fixed in the repository version.

Using five of these dual-cell cell testers it was possible to run through the hundreds of cells with ten cells at a time. An internal resistance meter was also wired into the PC-based software via its UART. As of publication of the video the testing was still in progress, which gives some idea of how long it takes to work through those cells.

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An Automated Water Tank Controller

August 2, 2026 by 25 Comments

[Jumpor] lives in a part of India where the water infrastructure is a little frustrating to use. Water gets delivered to underground tanks outside of homes, and must then be regularly pumped into rooftop tanks prior to use inside the building. Typically, this pumping is handled manually—by switching on a pump and running it until water comes out of an overflow pipe to indicate the rooftop tank is full. [Jumpor] decided to improve this wasteful and time consuming process with a little automation project.

The build is based around an ESP32 microcontroller. It’s hooked up to an ultrasonic sensor which can measure the water level inside the rooftop water tank. When the sensor detects the level descending below a set point, the microcontroller fires a relay to trigger the lift pump to fill up the tank. Once the sensor detects the tank is full, the pump is shut off, saving liters of water compared to waiting for water to pour out of the overflow as an indicator of the same.

It’s a simple enough project, but [Jumpor] was sure to include the important practical considerations. Since the rig was being installed in a rental, it was desirable to not make any permanent modifications to the water system. Thus, a fresh cap for the water tank was modified to host the electronics and level sensor, such that the original could be replaced at a later date. Due consideration was also paid to things like avoiding crossing the minimum detection threshold of the sensor, which could lead to accidental overflows if not managed correctly.

The aim of this project was to ease the day to day burden of maintaining a basic utility. That’s the sort of project we love to see around these parts.

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A Complex Way To Push A Button

July 31, 2026 by 17 Comments

We’ve likely all looked at a simple problem in our lives and thought that it would be an easy fix, only to realize that the project is enormously more complicated than we first realized. Whether that’s starting a home improvement project, doing a quick repair to a bicycle or car, or trying to install an obscure piece of software on a Linux machine, the amount of time we budget for these tasks often ends up woefully underestimated. [Oscar]’s night light needs to have its brightness set every night, and it seems easy enough to get a microcontroller to automate that, right?

Well, upon opening the small device, the first issue is that there is no labeling on any of the parts, so simply adding a jumper on to existing microcontroller pins without damaging anything wouldn’t easily be possible. Adding a secondary microcontroller is the next logical step, but the power supply in the night light is extremely underpowered so using even the smallest Raspberry Pi or off-the-shelf Arduino was out of the question too. [Oscar] instead chose an ATtiny85, which solves the power requirement issue, but these are a bit more of a challenge to program without a USB device. From there, it needs a transistor wired in to the circuit to actually push the button for him, plus a few support resistors, so [Oscar] actually had a PCB custom-built to hold all of these components.

Even after all of that, the space within the night light enclosure made installing the PCB a challenge, but in the end he has a device which, when his home automation system powers on the plug for the nightlight, automatically boots up and pushes the switch the required number of times and then puts itself to sleep. We’d call that a success even after the colossal effort getting this inexpensive, small light working the way he wanted. There are some other low-powered solutions for problems like these too, as long as being battery-powered isn’t a dealbreaker.

Neural Net Reads The Gas Meter

July 21, 2026 by 25 Comments

In an ideal world, the role of technology would be to make all of our lives easier. And although all the ads suddenly appearing in our smart TVs and gaming systems might make it seem otherwise, some technology can still improve our lives if we work hard at it. For [Cian], that meant training a neural network to read his gas meter so he wouldn’t have to do it himself.

The root issue here is twofold, first that [Cian]’s gas company hasn’t upgraded their own technology to modern, remote-readable meters, and second that the meter can’t be read by a gas employee because it’s hidden in the depths of [Cian]’s basement. This latter fact requires him to delve into Moria-like depths to get to the meter, so the solution here was to place a Raspberry Pi in this location instead. With a camera pointed at the meter, it’s not quite capable of discerning digits on its own so a neural network was trained in order to get accurate readings of the dial. And, finally, since the machine is networked already [Cian] set it up to automatically notify the gas company of its reading so he is now completely out of the loop.

For automating tedious tasks like these, the Raspberry Pi with something like OpenCV as a computer vision tool is a fairly mature platform for light machine learning duties like these. We’ve seen license plate readers as well as neighborhood traffic surveys built on these platforms to help automate human labor away, making our lives easier one single-board computer at a time.

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Chicken Coop Door Performs In Harsh Environment

April 3, 2026 by 22 Comments

One of the pitfalls of modern engineering is that it’s entirely possible to end up in a situation where a product or solution has been designed by someone who has never left a desk. Which wouldn’t be a problem if things didn’t have a tendency to work differently in real life than they do in theory.

One of those things is automatic chicken coop doors, which have to operate reliably in not only a wide range of climates but with a number of possible physical limitations as well. [Vinnie] has taken on the challenge of building one which actually accomplishes all of these tasks, after realizing that the off-the-shelf solutions were victims of design over practicality.

[Vinnie] designed this door to be operated by the one thing that’s always 100% reliable: gravity. A linear actuator lifts the door at the beginning of the day, and then at night it’s allowed to fall back down in its track. A latch secures it against smarter intruders like raccoons. [Vinnie] has found that this lifting mechanism holds up much better in mud, snow, ice, and other difficult conditions than any other method he’s tried so far.

The system is built around a ATmega1284P, and calculates the sunrise and sunset times each day to know when to open or close the door. He’s built the system as a state machine which makes it more robust during power outages, which is a necessity since his chicken coop is mobile and is frequently out of range of WiFi and is battery powered.

The approach [Vinnie] takes to automation is something that has application outside of his own farmstead. Using state machines instead of schedules, ensuring the design is as simple as possible and works within its environment, and minimizing reliance on electric and data infrastructure can go a long way to solving problems that might not appear when designing something on paper.

He’s been automating many other things on his farm as well, and it’s worth checking it out if you haven’t seen it already.

Robots Talking To Robots

February 7, 2026 by 7 Comments

Although there are a few robots on the market that can make life a bit easier, plenty of them have closed-source software or smartphone apps required for control that may phone home and send any amount of data from the user’s LAN back to some unknown server. Many people will block off Internet access for these types of devices, if they buy them at all, but that can restrict the abilities of the robots in some situations. [Max]’s robot vacuum has this problem, but he was able to keep it offline while retaining its functionality by using an interesting approach.

Home Assistant, a popular open source home automation system, has a few options for voice commands, and can also be set up to transmit voice commands as well. This robotic vacuum can accept voice commands in lieu of commands from its proprietary smartphone app, so to bypass this [Max] set up a system of automations in Home Assistant that would command the robot over voice. His software is called jacadi and is built in Go, which uses text-to-speech to command the vacuum using a USB speaker, keeping it usable while still offline.

Integrating a voice-controlled appliance like this robotic vacuum cleaner allows things like scheduled cleanings and other commands to be sent to the vacuum even when [Max] isn’t home. There are still a few limitations though, largely that communication is only one way to the vacuum and the Home Assistant server can’t know when it’s finished or exactly when to send new commands to the device. But it’s still an excellent way to keep something like this offline without having to  rewrite its control software entirely.

DIY, Full-Stack Farm Automation

January 16, 2026 by 13 Comments

Recently, [Vinnie] aka [vinthewrench] moved from Oregon to Arkansas to start a farmstead. This is a style of farming that focuses not just on a profitable farm where produce is sold at market, but also on a homestead where much of one’s own food is grown on the farm as well. Like any farm, though, it’s extremely hard work that takes a tremendous amount of time. Automation and other technology can make a huge impact in these situations, and [Vinnie] is rolling out his own software stack to help with this on his farm.

He calls his project the Pi Internet of Things, or PioT, and as its name suggests is based around the Raspberry Pi. Since this will all be outdoors and exposed to the extremes of Arkansas weather, everything built under the auspices of this project prioritizes ruggedness, stability, and long-term support, all while avoiding any cloud service. The system also focuses on being able to ride through power outages. The server side, called piotserver, uses a REST API to give the user access to the automation systems through a web interface

[Vinnie] also goes into detail about why existing systems like Home Assistant and Open Sprinkler wouldn’t work in his situation, and why a ground-up solution like this is more appropriate for his farm. This post is largely an overview of his system, but some of his other posts go into more detail about things like integrating temperature sensors, rainfall monitoring, controlling irrigation systems, and plenty of other farm automation tasks that are useful for any farmer or gardener.

We’ve also seen some other projects of his here like this project which converts a common AC sprinkler system to an easier-to-use DC system, and a DIY weather station that operates in the 915 MHz band. He’s been a great resource for anyone looking to have technology help them out with their farm or garden, but if you’re just getting started on your green thumb be sure to take a look at this starter guide as well.