An Epic Quest For A Motorized Volume Knob

December 7, 2020 by Tom Nardi 23 Comments

[Haris Andrianakis] likes his Logitech Z623 sound system. He likes it a lot. Which is why he was willing to hack in his own remote volume control rather than just get a new pair of speakers. But he certainly didn’t make things easy on himself. Rather than trying to tap into the electronics, he decided to take the long way around and motorize the volume knob.

The belt drive looked great, but didn’t work.

The idea seemed simple enough. Just drill a hole through the PCB behind the knob’s potentiometer, attach some kind of extension to the axle, and turn it with a small servo. Modifying the PCB and potentiometer went well enough, but the trouble came when [Haris] actually tried to turn the thing.

Attaching the servo directly to the axle worked, but it made turning the knob by hand extremely difficult. His next idea was to add a small belt into the mix so there would be some slip in the system. But after designing a 3D printed servo mount and turning custom pulleys on the lathe, it ended up having too much slip, and the knob didn’t always move when the servo turned.

He then swapped out the servo for a small stepper motor. The motor was easy enough to spin when powered down, but didn’t have quite enough torque to turn the knob. He tried with a larger stepper motor that he salvaged from an old printer, but since he could only run it at half the recommended 24 VDC, it too had a tendency to skip steps.

After experimenting with some 3D printed reduction gears, [Haris] finally stumbled upon the 28BYJ-48. This small stepper with an integrated gearbox proved to be the perfect solution, as it had enough muscle to turn the knob while at the same time not restricting its movement when powered down. The rest of the project was relatively easy; with a DRV8825, an ESP8266, and an IR receiver, he’s able to spin the stepper with his TV’s remote. A simple web page running on the ESP8266 even allows him to control volume over the network with his smartphone. Based on similar projects we’ve seen, he could probably add support for HDMI CEC as well.

[Haris] says you shouldn’t follow his example, but we’re not so sure. He kept going when others would have given up, and the engineering and thought that went into each attempt is certainly commendable. Even if he hadn’t ultimately gotten this project working, we’d still say it was a valiant hack worthy of praise.

Norway Leads The Charge To Phase Out Internal Combustion; China And The UK To Follow

December 7, 2020 by Lewin Day 194 Comments

Climate change promises to cause untold damage across the world if greenhouse gas emissions continue at current levels for much longer. Despite the wealth of evidence indicating impending doom, governments have done what humans do best, and procrastinated on solving the issue.

However, legislatures around the world are beginning to snap into action. With transportation being a major contributor to greenhouse gas emissions — 16% of the global total in 2016 — measures are being taken to reduce this figure. With electric cars now a viable reality, many governments are planning to ban the sale of internal combustion vehicles in the coming decades.

Continue reading “Norway Leads The Charge To Phase Out Internal Combustion; China And The UK To Follow” →

Slim RGB Matrix Puts LEDs Inside The PCB

December 7, 2020 by Danie Conradie 16 Comments

Sometimes all that’s required to build something interesting is to put the same old pieces together differently. [Sayantan Pal] did this for the humble RGB LED matrix, creating an extra-thin version by recessing WS2812b NeoPixel LEDs inside a PCB.

The popular WS2812B is 1.6 mm in height, which happens to be the most commonly used PCB thickness. Using EasyEDA, [Sayantan] designed a 8×8 matrix with modified WS2812B footprints. A slightly undersized cutout was added to create a friction-fit for the LEDs, and the pads were moved to the back side of the panel just outside the cutout, and their assignment were flipped. The PCB is assembled face down, and all the pads are soldered by hand. Unfortunately this creates rather large solder bridges which slightly increases the overall thickness of the panel, and is probably also unsuitable for production with conventional pick-and-place assembly.

We’ve seen some similar methods with PCB assemblies that use layered PCBs. Manufacturers are starting to even embed components inside multilayer PCBs.

A Brain Transplant For An Uncommon Smart Bulb

December 7, 2020 by Jenny List 6 Comments

By now it’s a hardware hack that’s become common enough to be unremarkable, taking a smart light bulb or other mains switchable appliance and replacing its firmware with an open-source equivalent such as Tasmota. But what can be done when a new device is found to have a microcontroller unsupported by any open-source equivalents? If you are [Luca Dentella], you don’t throw in the towel and buy another one with a known processor, instead you reverse engineer it enough to give it a brain transplant of an ESP8266 module.

The Fcmila branded smart bulb in question was found to have a relatively unknown Chinese SoC, the Opulinks OPL1000. Since this couldn’t even raise a serial port it was more trouble than it was worth to write software for it, so instead he spent a while reverse engineering its schematic and electrical protocols, before grafting in a Wemos D1 ESP8266 board. He’s made a video about the project which you can see below the break.

Thankfully the majority of smart bulbs on the market seem to use more familiar hardware that can be flashed with relative ease.

Continue reading “A Brain Transplant For An Uncommon Smart Bulb” →