Pi Zero runs DOOM via wireless power

What's better than a Raspberry Pi Zero running DOOM on a 3.5″ touchscreen? Running it on wireless power, of course!

[atomic14] has been interested in wireless power for some time, and while most of the hardware he's tested over the years hasn't been impressive, he's demonstrated one capable of Reliably supply 5V at around 1A, which is more than enough to boot a Raspberry Pi W2 into X and launch DOOM. But while that's good, he explains that wireless power isn't an easy solution yet.

The hardware can deliver 5V at around 1A wirelessly, which is plenty, but coil alignment is critical to efficiency.

For one thing, the hardware it uses, similar to those used for charging cell phones, requires the receiver to be very close to the transmitter. In addition, they must be well aligned or the efficiency drops sharply. For mobile phones this isn't much of a problem, but it's difficult to position a Raspberry Pi and display just when you can't see the coils. Misalignment means brownouts and other unreliable operations.

So while the wireless power supply is capable of running the Pi directly, [atomic14] attempts to add a small battery and charger circuit to make the whole thing both portable and more reliable. But because nothing is easy, he discovers that his load board - which should be able to output as little as 4.5 V - cannot be adjusted below 5.66 V. It turns out that a resistor marked 104 (which should be 100 kΩ) measures actually 57 kΩ, and the pot does not drop below 10 kΩ. The solution is a bit of component swapping, but we guess that's a reminder that sometimes with cheap parts you pay another way.

You can see [atomic14]'s Raspberry Pi wireless power supply running the classic shooter in the video below. Wireless power can have its issues, but it's certainly a lot less messy than running DOOM with a gigantic potato battery.

Thanks to [Chris] for the tip!