Autonomous Plant Watering Thingamajig

[Eitan] is one of those guys whose plants keep tottering between life and death. Can’t blame the plants, because he just keeps forgetting when to water them. But keeping them hydrated requires him to get off his butt and actually water them. Surely, there had to be an easier solution which needed him to do nothing and yet prevent his plants from dying. Being lazy has its benefits, so he built his own super simple Autonomous Plant Watering Thingamajig.

He needed a water pump, but all he had was an air pump. So he hooked it up to force air in to a sealed container and push the water out. To make the setup autonomous, he connected the pump to a WiFi-enabled wall socket and then programmed it to dispense water at regular intervals. It may take him some time to fine tune the right interval and duration for his setup over the next few weeks, but right now, it’s pumping water for a short duration once every week.

The important thing for a system like this to work is to ensure it is well sealed. Any air leakage will require an increasing amount of air to be pumped in to the container as the water level keeps reducing. Without knowing the actual level of water in the container, it isn’t easy to compensate for this via programming. And that’s the other problem. [Eitan] will still have to periodically check his mason jar for water, and top it up manually. Maybe his next hack will take care of that. We’re thinking a Rube Goldberg watering system would be awesome. It’s nice when people put on their thinking caps and say “Okay, here’s a problem, how do I solve it?” instead of going out and buying an off-the-shelf device.

Thanks, [Clay], for sending in this tip.

A pick and place tool from medical equipment


A vacuum tool is an invaluable tool if you’re working with tiny SMD parts, and even with tweezers you might have a hard time placing these nearly invisible components on their pads for soldering. One tool that’s really great for these parts is a vacuum pen, usually made from an old aquarium air pump. [Jon] may have found a much more suitable piece of equipment to scavenge for a vacuum pen build – a nebulizer.

Nebulizers provide asthmatics with low pressure, low volume air to atomize medication for inhalation. Inside the nebulizer is a small diaphragm pump, just like the small aquarium pump teardowns we’ve seen. In just five minutes, [Jon] tore his thrift store nebulizer apart and reversed the flow of air, turning something that blows into something that sucks.

After the suction part of the build was finished, [Jon] needed a way to pick up small components. He did this by blunting a large hypodermic needle and fastening it to the end of a Bic pen with heat shrink tubing. After drilling a small hole in the pen body, he had a very nice looking SMD vacuum pump.