Low-Cost Head Mounted Display From FPV Gear

January 4, 2021 by Tom Nardi 17 Comments

A common complaint we’ve seen on many of the recent cyberdeck builds is that they don’t offer any display technology more advanced than a tablet-sized IPS panel. The argument goes that to be a true deck in the Gibsonian sense, it’s got to have some kind of virtual reality interface or at least a head mounted display. Unfortunately such technology is expensive, and often not particularly hacker friendly.

But assuming you can settle for a somewhat low-tech alternative, the simple head mounted display that [Jordan Brandes] has been fiddling with is certainly a viable option. By mounting a five inch 800×480 TFT LCD to the front of a pair of goggles designed for first person view (FPV) flying, you can throw together a workable rig for around $30 USD. Add in some headphones, and you’ve got a fairly immersive experience for not a lot.

Naturally the display will show whatever HDMI signal you give it, but in his case, [Jordan] has mounted a Raspberry Pi to the back of it to make it a complete wearable computer. With a Bluetooth travel keyboard in the mix, he’s even able to get some legitimate work done with this setup. If he ends up combining this with the ultrasonic keyboard he was working on earlier in the year, he’ll be getting pretty close to jacking into cyberspace for real.

Hackers have been chasing cheap head mounted displays for years now. Back in 2007 the best you could do for this kind of money was a 300×240 black and white monocle. Getting our hands on the good stuff is still harder than we’d like, but at least we’re moving in the right direction.

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Custom Powerbank In Compact Form Factor

December 27, 2020 by Danie Conradie 28 Comments

The wide availability and power density of 18650 lithium-ion cells have made them a good option for everything from electric cars to flashlights. [Theo] needed a new power source for his FPV drone goggles, so he designed his own power bank with a very compact charge controller.

While [Theo] could charge the batteries with an RC battery charger, he preferred the convenience of one with a standard 5V micro USB input, and wanted battery level indication to avoid having the FPV goggles die unexpectedly mid-flight. When four 18650 cells are held in a cube arrangement, a 8x8x65 mm gap is formed between the cells. In this space [Theo] was able to fit a custom PCB with a micro USB jack, 1.3 mm power jack, BQ25606 charge controller, TPS61085 boost converter, and ATtiny MCU with LED for battery level feedback. The charge controller also allows 5V devices to be charged via USB, while the boost converter outputs 9V via the 1.3mm jack for [Theo]’s FPV goggles. Everything fits inside a nice compact 3D printed enclosure.

The project was not without hiccups. After ordering and building the PCB he discovered some minor PCB layout mistakes, and realized the boost converted could only output 600mA at 9V, which was not enough for his more power-hungry googles. He plans to fix this in the next version.

We’ve seen custom power banks in quite a few shapes and sizes, including one that runs on power tool batteries (which probably also have 18650s inside) and one that has just about every output you could want, including AC and wireless QI charging.