Tricked-Out Tablet Becomes Workbench Tool

The workbench of the typical electronics hobbyist today would probably be largely recognizable by Heathkit builders back in the 60s and 70s. But where the techs and tinkerers of yesteryear would have had a real dead-tree SAMS Photofact schematic spread out on the bench, today you’ll get more use out of a flat-screen display for data sheets and schematics, and this handy shop Frankentablet might be just the thing to build.

Tablets like the older Nexus 9 that [enginoor] used as the basis for this build have a little bit of a form-factor problem because unlike a laptop, a tablet isn’t very good at standing up on its own. To fix that, they found a suitable silicone skin for the Nexus, and with some silicone adhesive began bedazzling the back of the tablet. A bendy tripod intended for phones was added, and with the tablet able to stand on its own they maximized the USB port with a right angle adapter and a hub. Now the tablet has a USB drive, a mouse, and a keyboard, ready for perusing data sheets online. And hackers of a certain age will appreciate the eyeball-enhancing potential of the attached USB microscope.

[enginoor]’s bench tablet is great, but we’ve seen full-fledged bench PCs before too. Take your pick — wall mounted and floating, or built right into the workbench.

Thanks to [ccvi] for the tip.

23 thoughts on “Tricked-Out Tablet Becomes Workbench Tool

  1. Not a microscope in the photo it’s an endoscope. Their focal length is too long to work well as a microscope – I know because I bought one with the intent of using it as a microscope. You can have ’em for <$5 so still fun.

    1. I have one myself. It’s one of those tools that it’s so cheap it’s worth having just incase which is why I bought it when I first saw it by accident.
      I’ve used it for many things that no other tools would do the job as easily.
      I have an old webcam modified for “microscope” duty

  2. Did this have any solution to the ‘charge device and use OTG at the same time’ problem?

    I did read the article; but didn’t see anything that looked like it was delivering power to the tablet while it was acting as a USB host; and I looked because it’s a problem that has been bothering me for some time.

    You can get plenty of OTG adapters with provision for injecting additional power for the slave device(eg. external HDD that a phone doesn’t provide power for); but I haven’t been able to find anything that allows you to charge the host device while slave devices are attached; unless the OTG device has more than one port or a separate power jack, which is relatively rarely the case. Most of the phones and small tablets have just the one port that is both the only way to charge it and the only peripheral connection option.

    Anyone know of external cabling that works; or a modification that is reasonably unlikely to toast the target device?

    1. There available on Amazon for $5-10 bucks, and they do work. Just be careful to only use standard 5v chargers when using them, and avoid any quick charging chargers that output 5-12v that may have come with the phone/tablet. It’s a good way to fry whatever USB peripheral you have attached. I personally use a 3.5amp 5v USB charger in my setup and it works great even for high power phones and tablets.

        1. Thanks. So the “**Note: This is not designed to charge the phone or tablet. The power source provides power to the external source such as a mouse or external hard drive.” in the item description is a lie?

    2. What I did was add a second charge controller directly to the battery a TP4056 and charge though that when still using OTG though the tables built in port. Mind you I am using a almost 4 year old tablet running android 4.4, and had to mod the case a bit.

      1. I forgot to add, I placed a schottky diode so that the tablet could no longer charge the battery, only discharge. I do not know if this would work on a more modern tablet, but mine did not care. I also used a TP4056 with a built in protection circuit and a dual current circuit so that power would pull from the input if that was gone then it would pull from the battery instead (really just 2 schottky diode and a capacitor, think poor mans DC UPS)

          1. To prevent the battery from cycling though its lifetime of charge discharge cycles. If my power source only charge the battery and the tabled only discharged the battery, I would go though charge 100 mA, discharge 100 mA, again and again. This way once the battery is charged it would only start to discharge once the power source was no longer connected.

    3. Simultaneous use as a USB host and charging port is a functionality that unfortunately is dependent on the device. I used to use a Motorola Droid Bionic with a Lapdock. It’s a phone that plugged in to a little laptop-like hdmi screen/keyboard/track pad/USB hub combo. That of course charged the phone at the same time.

      Anyway, through experimentation I found that by adding certain values of resistors between the data lines I could get the phone to act as any combination of USB host/slave and power in/out.

      Other devices work similarly but which combinations are available and what values of resistors to use vary. Manufacturers are jerks that do not like to follow standards. When the Bionic became too old and slow to continue using I wanted to hook a cheap tablet to the Lapdock instead. That didn’t work. I tried all sorts of different resistor values, that device just didn’t support being a USB host and charging itself at the same time.

      So, yes, you can buy a cable, made for a specific device which does USB host and charging at the same time. It MIGHT work, it might not.

  3. I like this project a lot. Looks pretty sweet and good use of the tripod. I have always just used my second string laptop on the bench for general datasheets, pinouts, uc programming etc. I even had a thrift find webcam attached to my arm light to do magnification of components, demo vids etc. Definitely a handy tool to have around.

  4. I would scream “NOT A HACK N00B!”, but it is charming in its simplicity and practicality in almost a catharticly sublime way. I’m also envious of it because my setup is far from perfect.

  5. When flying I found a RAM x-clamp which uses some screws to attach to a yoke shaft clamp adapter, mostly use for checklists and maps, rarely for dump1090 ADS-B area ‘radar’ display with RTL-SDR. The X holder works good for the tablet in its silicone and hard plastic skin/case and if I were to want to mount it elsewhere I would probably make a 3D printed adapter to attach to a stand. Outside the cockpit I carry the Nexus 7 in its skin/case around in a USB keyboard folio case mostly for screen protection or doing some field hacking mostly for SSH or field programming arduinos and digisparks(or bare bones USB ATtiny85 programmers).
    I still prefer a laptop in my home work lab but the de-googled Nexus(LneageOSn f-Droidn, no gapps) is good for doing work out of the lab especially on a vehicular job I am doing even to just look for help or troubleshooting guides online.

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