Reverse-Engineering An Amazon Blink Gen 3 Camera

April 13, 2026 by Maya Posch 10 Comments

After some water intrusion apparently killed one of [electronupdate]’s Amazon Blink Gen 3 cameras he took this opportunity to do a full teardown and analysis of all the major components. Spread across its three PCBs there are no fewer than two wireless ICs and a custom ASIC for all the major processing. There’s also a blog post with easy-to-ogle pictures.

The most basic PCB is effectively just a PCB antenna for the Silicon Labs EZR32 IC on the main PCB, using which the ~915 MHz connection with the central hub is maintained. The other smaller PCB is a bit surprising in that it contains a Cypress CYW43438 W-Fi b/g/n and BT 5.1 chip. This would seem to be used for the setup process, but considering that it also uses a central hub it is a bit of a mystery as to what it is used for exactly.

Finally, the main PCB contains all the major parts, with the custom Amazon Immedia ASIC that’s an integral part of this very low-power camera. Given that two AA cells being enough to run the camera for about two years, using off-the-shelf parts probably wasn’t good enough without some serious customization.

As for why this outdoors-rated camera failed after a few years in the outdoors, the reason appears to be water intrusion via the speaker opening. As for why a camera needs a speaker and not just the microphone is left as an exercise to the reader, but maybe it could be useful for yelling at the local kids to get off your darn lawn?

Continue reading “Reverse-Engineering An Amazon Blink Gen 3 Camera” →

Heathkit Tuner Saved From Junk Pile

April 4, 2026 by Al Williams 4 Comments

We miss the old Heathkit. You could build equipment that rivaled or even surpassed commercial devices. The cost was usually reasonable and, even if you could get by with less, the satisfaction of using gear you built yourself was worth a lot. Not to mention the knowledge you’d gain and your confidence in troubleshooting should the need arise. So we were jealous of [RCD66] when he found a Heathkit AJ-43C stereo tuner in the recycle bin.

As you can see in the video below, it needed a lot of love to get back to its former self. The device dates from around 1965, when the kit cost $130. In 1965, that was a lot of money. Back then, that would have bought you about four ounces of gold and would have been a great down payment on a $1,500 VW bug.

Things were a bit of a mess, so he removed all the parts and replaced most of them. Unsurprisingly, the electrolytic capacitors all tested bad. The transistors were all germanium, but if they tested good, his plan was to reuse them. There were several PCBs inside, and he made some changes, such as replacing the zener diode power supply with something more modern.

How did it sound? Watch the video and see for yourself. We usually like troubleshooting specific problems on gear like this, but in this case, it was probably smart to just do a total rework.

Heathkit had quite an origin story. This isn’t the first time we’ve seen someone strip and rebuild a Heathkit.

Continue reading “Heathkit Tuner Saved From Junk Pile” →

Reverse-Engineering A Handheld Car Tire Pressure Gauge

April 3, 2026 by Maya Posch 6 Comments

The SDIC 8-bit MCU. (Credit: electronupdate, YouTube)

In this wonderful world of MEMS technology, sensor technology has been downsized and reduced in cost to the point where you can buy a car tire pressure sensor for less than $3 USD on a site like AliExpress. Recently [electronupdate] got his mittens on one of these items to take a look inside, and compare it against his trusty old mechanical tire pressure gauge.

Perhaps unsurprisingly, there isn’t a whole lot inside these devices once you pop them open to reveal the PCB. The MEMS device is a tiny device at the top, which has the pressurized air from the tire guided to it. The small hole inside the metal can leads to the internals that consist of a thin diaphragm with four piezoresistors that enable measurements on said diaphragm from which pressure can be determined.

Handling these measurements and displaying results on the small zebra connector-connected LCD is an 8-bit MCU manufactured by Chinese company SDIC. Although the part number on the die doesn’t lead to any specific part on the SDIC site, similar SDIC parts have about 256 bytes of SRAM and a few kB of one-time programmable ROM.

This MCU also integrates the clock oscillator, thus requiring virtually no external parts to work. Finally, its sigma-delta ADC interacts with the MEMS device, rounding out a very simple device that’s nevertheless more than accurate enough for a spot check as well as quite portable.

Continue reading “Reverse-Engineering A Handheld Car Tire Pressure Gauge” →

Post-Failure Autopsy And Analysis Of An LFP Battery

April 2, 2026 by Maya Posch 8 Comments

Recently [Kerry Wong] had one of his Cyclenbatt LiFePO₄ batteries die after only a few dozen cycles, with a normal voltage still present on the terminals. One of the symptoms was that as soon as you try to charge it, the voltage goes up very rapidly to above 14 V due to what appears to be high internal resistance, and vice versa for discharging. In addition, the Bluetooth feature of the BMS appeared to have died as well, making non-invasive diagnostics somewhat tricky.

Close-up of the BMS. (Credit: Kerry Wong, YouTube)

After gently cutting open the plastic case, [Kerry] was greeted by the happily blinking blue LED of the Bluetooth module and deepening the mystery. Overall the build quality looks to be pretty good, with no loose cables as seen with certain other LFP batteries.

Cell voltages measured normal, with no significant imbalance. Next was measuring the internal resistance, which showed a clear issue. One of the cells was reading over 3 Ohms, whereas the others were in the milli-Ohm range. This would definitely explain the issues with charging and discharging, with a single bad cell causing most of the issues.

Of course, why the Bluetooth feature failed remains a mystery, and there’s still a lingering question on whether the BMS practiced proper balancing between the cells, as this can also cause issues over time.

Continue reading “Post-Failure Autopsy And Analysis Of An LFP Battery” →

Soviet CDs And CD Players Existed, And They Were Strange

March 29, 2026 by Maya Posch 9 Comments

Until the fall of the Soviet Union around 1990 you’d be forgiven as a proud Soviet citizen for thinking that the USSR’s technology was on par with the decadent West. After the Iron Curtain lifted it became however quite clear how outdated especially consumer electronics were in the USSR, with technologies like digital audio CDs and their players being one good point of comparison. In a recent video by a railways/retro tech YouTube channel we get a look at one of the earliest Soviet CD players.

A good overall summary of how CD technology slowly developed in the Soviet Union despite limitations can be found in this 2025 article by [Artur Netsvetaev]. Soviet technology was characterized mostly by glossy announcements and promises of ‘imminent’ serial production prior to a slow fading into obscurity. Soviet engineers had come up with the Luch-001 digital audio player in 1979, using glass discs. More prototypes followed, but with no means for mass-production and Soviet bureaucracy getting in the way, these efforts died during the 1980s.

During the 1980s CD players were produced in Soviet Estonia in small batches, using Philips internals to create the Estonia LP-010. Eventually sanctions on the USSR would strangle these efforts, however. Thus it wouldn’t be until 1991 that the Vega PKD-122 would become the first mass-produced CD player, with one example featured in this video.

Continue reading “Soviet CDs And CD Players Existed, And They Were Strange” →

How A Belkin USB Charger Pulls Off A 3 Milliwatt Standby Usage

March 22, 2026 by Maya Posch 21 Comments

Belkin charger standby power. (Credit: Denki Otaku, YouTube)

A well-known property of wall warts like power bricks and USB chargers is that they always consume some amount of power even when there’s no connected device drawing power from them. This feels rather wasteful when you have a gaggle of USB chargers constantly plugged in, especially on a nation-sized scale. This is where a new USB-C wall charger by Belkin, the BoostCharger Pro, is interesting, as it claims ‘zero standby power’, which sounds pretty boastful and rather suspect. Fortunately, [Denki Otaku] saw fit to put one to the test and even tear one down to inspect the work of Belkin’s engineers.

Naturally, no laws of physics were harmed in the construction of the device, as ‘zero standby power’ translated from marketing speak simply means ‘very low standby power usage’, or about 3 milliwatt with 0.3 mA at the applied 100 VAC.

Fascinatingly, plugging in an e-marker equipped USB-C cable with no device on the other end caused this standby usage to increase to about 30 mW, clearly disabling the ‘zero standby’ feature. With that detail noted, it was time to tear down the charger, revealing its four PCBs.

Continue reading “How A Belkin USB Charger Pulls Off A 3 Milliwatt Standby Usage” →

Studying A Battle Born LFP Battery’s Death Under Controlled Conditions

March 19, 2026 by Maya Posch 30 Comments

The test setup for the Battle Born LFP cycling. (Credit: Will Prowse, YouTube)

There has been quite a bit of news recently about the Battle Born LiFePO₄ (LFP) batteries and how they are dying in droves if not outright melting their plastic enclosures. Although the subsequent autopsies show molten plastic spacers on the bus bars and discolored metal in addition to very loose wiring, it can be educational to see exactly what is happening during repeated charge-discharge cycles at a fraction of the battery’s rated current. Thus [Will Prowse] recently sacrificed another Battle Born 75 Ah LFP battery to the Engineering QA Gods.

This time around the battery was hooked up to test equipment to fully graph out the charging and discharging voltage and current as it was put through its paces. To keep the battery as happy as possible it was charged and discharged at a mere 49A, well below its rated 100A.

Despite this, even after a mere 14 cycles the battery’s BMS would repeatedly disconnect the battery, as recorded by the instruments. Clearly something wasn’t happy inside the battery at this point, but the decision was made to push it a little bit harder while still staying well below the rated current.

Continue reading “Studying A Battle Born LFP Battery’s Death Under Controlled Conditions” →