Arduinos! They’re a great tool that make the world of microcontrollers pretty easy, and in [cptlolalot]’s case, they also give us an alternative to buying expensive, proprietary parts. [cptlolalot] needed a gauge for an expensive vacuum pump, and rather than buying an expensive part, built a circuit around an Arduino to monitor the vacuum.
This project goes a little beyond simple Arduino programming though. A 12V to 5V power supply drives the device, which is laid out on a blank PCB. The display fits snugly over the circuit which reduces the footprint of the project, and the entire thing is housed in a custom-printed case with a custom-printed pushbutton. The device gets power and data over the RJ45 connection so no external power is needed. If you want to take a look at the code, it’s linked on [cptlolalot]’s reddit thread.
This project shows how much easier it can be to grab an Arduino off the shelf to solve a problem that would otherwise be very expensive. We’ve been seeing Arduinos in industrial applications at an increasing rate as well, which is promising not just because it’s cheap but because it’s a familiar platform that will make repairs and hacks in the future much easier for everyone.











But before that, it’s time to bid farewell to the cheeky little popup window that would deliver a warning message when using a board bearing the USB IDs of their former-partner-turned-competitor. We absolutely 
The projector itself is the HD25-LV, a 3500 Lumen model from Optima. the HD25-LV is capable of 1080p, though in this situation, brightness is much more important than resolution. [Mikeasaurus] mounted the projector along with a gel cell battery and 900 watt DC to AC inverter to power it. A mobile WiFi hotspot fills out the rooftop kit. Leaving an expensive setup like that on top of a car is a recipe for disaster – be it from rain, rocks, or theft. [Mikeasaurus] thought ahead and strapped his setup down inside a roof mounted cargo box. A plastic covered hole in the front of the box allows the projector to shoot down on the road while protecting its lens. We’d want to add a vent and fan to ensure that projector gets a bit of airflow as well.