Fail Of The Week: Subscription EV Charger Becomes Standalone, Briefly

November 1, 2024 by Dan Maloney 48 Comments

At this point in the tech dystopia cycle, it’s no surprise that the initial purchase price of a piece of technology is likely not the last payment you’ll make. Almost everything these days needs an ongoing subscription to do whatever you paid for it to do in the first place. It’s ridiculous, especially when all you want to do is charge your electric motorcycle with electricity you already pay for; why in the world would you need a subscription for that?

That was [Maarten]’s question when he picked up a used EVBox wall mount charger, which refused to charge his bike without signing up for a subscription. True, the subscription gave access to all kinds of gee-whiz features, none of which were necessary for the job of topping off the bike’s battery. A teardown revealed a well-built device with separate modules for mains supply and battery charging, plus a communications module with a cellular modem, obviously the bit that’s phoning home and keeping the charger from working without the subscription.

Continue reading “Fail Of The Week: Subscription EV Charger Becomes Standalone, Briefly” →

Reverse Engineering Keeps Early Ford EVs Rolling

June 7, 2024 by Dan Maloney 5 Comments

With all the EV hype in the air, you’d be forgiven for thinking electric vehicles are something new. But of course, EVs go way, way back, to the early 19th century by some reckonings. More recently but still pretty old-school were Ford’s Think line of NEVs, or neighborhood electric vehicles. These were commercially available in the early 2000s, and something like 7,200 of the slightly souped-up golf carts made it into retirement communities and gated neighborhoods.

But as Think aficionado [Hagan Walker] relates, the Achille’s heel of these quirky EVs was its instrument cluster, which had a nasty habit of going bad and taking the whole vehicle down with it, sometimes in flames. So he undertook the effort of completely reverse engineering the original cluster, with the goal of building a plug-in replacement.

The reverse engineering effort itself is pretty interesting, and worth a watch. The microcontroller seems to be the primary point of failure on the cluster, probably getting fried by some stray transients. Luckily, the microcontroller is still available, and swapping it out is pretty easy thanks to chunky early-2000s SMD components. Programming the MCU, however, is a little tricky. [Hagan] extracted the code from a working cluster and created a hex file, making it easy to flash the new MCU. He has a bunch of other videos, too, covering everything from basic diagnostics to lithium battery swaps for the original golf cart batteries that powered the vehicle.

True, there weren’t many of these EVs made, and fewer still are on the road today. But they’re not without their charm, and keeping the ones that are still around from becoming lawn ornaments — or worse — seems like a noble effort.

Continue reading “Reverse Engineering Keeps Early Ford EVs Rolling” →

Console Calculator Moves One Step Closer To Original Design

May 24, 2024 by Dan Maloney 14 Comments

With smartphone apps and spreadsheets being the main ways people crunch their numbers nowadays, there’s not much call for a desktop calculator. Or any other physical calculator, for that matter. Which is all the more reason to appreciate this Wang 300-series calculator console’s revival through a new electronic backend.

If you haven’t made the acquaintance of the Wang calculator series, [Bob Alexander]’s previous Wang project is a perfect introduction. Despite looking very much like an overbuilt early-70s desktop calculator, what you see in the video below is just a terminal, one of four that could connect to a shared “Electronics Package” where most of the actual computational work was done. The package was big and is currently hard to come by, at least at a reasonable price, but the consoles, with their Nixie displays and sturdy keypads, are relatively abundant.

[Bob]’s previous venture into reviving his console involved embedding a PIC32-based controller, turning it into the standalone desktop calculator it never was. To keep more with the original design philosophy, [Bob]’s second stab at the problem moves much of the same circuitry from inside the console into a dedicated outboard package, albeit one much smaller than the original. The replacement package extends and enhances the console functionality a bit, adding a real-time clock and a Nixie exercise routine to ward off the dreaded cathode poisoning. [Bob] also recreates the original Wang logarithmic method of multiplication and division, which is a nice touch with its distinctive flashing display.

Seeing the Wang console hooked up to a package through that thick cable and Centronics connector is oddly satisfying. We’d love to see [Bob] take this to the logical extent and support multiple consoles, but that might be pushing things a bit.

Continue reading “Console Calculator Moves One Step Closer To Original Design” →

Saving PIC Microcontrollers With DIY Programmer

January 14, 2024 by Bryan Cockfield 32 Comments

When working on a project, plenty of us will reach for an Atmel microcontroller because of the widespread prevalence of the Arduino platform. A few hackers would opt for a bit more modern part like an ESP32. But these Arduino-compatible platforms are far from the only microcontrollers available. The flash-based PIC family of microcontrollers is another popular choice. Since they aren’t quite as beginner or user-friendly, setting up a programmer for them is not as straightforward. [Tahmid] needed to program some old PIC microcontrollers and found the Pi Pico to be an ideal programmer.

The reason for reaching for the Pico in the first place was that [Tahmid] had rediscovered these decade-old microcontrollers in a parts bin but couldn’t find the original programmer. Thanks to advances in technology in the last ten years, including the advent of micropython, the Pico turned out to be the ideal programmer. Micropython also enables a fairly simple drag-and-drop way of sending the .hex file to the PIC, so the only thing the software has to do is detect the PIC, erase it, and flash the .hex file. The only physical limitation is that the voltages needed for the PIC are much higher than the Pico can offer, but this problem is easily solved with a boost converter (controlled by the Pico) and a level shifter.

[Tahmid] notes that there’s plenty of room for speed and performance optimization, since this project optimized development time instead. He also notes that since the software side is relatively simple, it could be used for other microcontrollers as well. To this end, he made the code available on his GitHub page. Even if you’re more familiar with the Arduino platform, though, there’s more than one way to program a microcontroller like this project which uses the Scratch language to program an ESP32.

Simple CMOS Circuit Allows Power And Data Over Twisted-Pair Wiring

November 21, 2023 by Dan Maloney 29 Comments

If you need to send data from sensors, there are plenty of options, including a bewildering selection of wireless methods. Trouble is, most of those protocols require a substantial stack of technology to make them work, and things aren’t much easier with wired sensors either. It doesn’t have to be that complicated, though, as this simple two-wire power-and-data interface demonstrates.

As with all things electronic, there are tradeoffs, which [0033mer] addresses in some detail in the video below. The basic setup for his use case is a PIC-based sensor — temperature, for this demo — that would be mounted in some remote location. The microcontroller needs to be powered, of course, and also needs to send a signal back to a central point to indicate whether the monitored location is within temperature specs. Both needs are accommodated by a single pair of wires and a tiny bit of additional circuitry. On one end of the twisted pair is a power supply and decoder circuit, which sends 9 volts up the line to power the PIC sensor. The decoder is based on a CD4538 dual monostable multivibrator, set up for an “on” time of one second. A trigger input is connected to the power side of the twisted pair going to the sensor, where a transistor connected to one of the PIC’s GPIO pins is set up to short the twisted pair together every half-second. Power to the PIC is maintained by a big electrolytic and a diode, to prevent back-feeding the controller. The steady 0.5-Hz stream of pulses from the sensor keeps resetting the timer on the control side. Once that stream stops, either through code or by an open or short condition on the twisted pair, the controller triggers an output to go high.

It’s a pretty clever system with very simple and flexible circuitry. [0033mer] says he’s used this over twisted-pair wires a couple of hundred feet long, which is pretty impressive. It’s limited to one bit of bandwidth, of course, but that might just be enough for the job. If it’s not, you might want to check out our primer on current-loop sensors, which are better suited for analog sensors but still share some of the fault-detection features.

Continue reading “Simple CMOS Circuit Allows Power And Data Over Twisted-Pair Wiring” →

Single Flex PCB Folds Into A Four-Wheel Rover, Complete With Motors

March 25, 2023 by Dan Maloney 3 Comments

You’ve got to hand it to [Carl Bugeja] — he comes up with some of the most interesting electromechanical designs we’ve seen. His latest project is right up there, too: a single PCB that folds up into a four-wheel motorized rover.

The key to [Carl]’s design lies with his PCB brushless motors, which he has been refining since we first spotted them back in 2018. The idea is to use traces on the PCB for the stator coils to drive a 3D printed rotor containing tiny magnets. They work surprisingly well, even if they don’t generate a huge amount of torque. [Carl]’s flexible PCB design, which incorporates metal stiffeners, is a bit like an unfolded cardboard box, with two pairs of motor coils on each of the side panels. This leaves the other surfaces available for all the electronics, with includes a PIC, a driver chip, and a Hall sensor for each motor, an IMU and proximity sensor for navigation, and an ESP32 to run the show.

With machined aluminum rotors and TPU tires mounted to the folded-up chassis, it was off to the races, albeit slowly. The lack of torque from the motors and the light weight of the rover, along with some unwanted friction due to ill-fitting joints, added up to slow progress, especially on anything other than a dead flat surface. But with some tweaking, [Carl] was able to get the buggy working well enough to call this one a win. Check out the build and testing in the video below.

Knowing [Carl], this isn’t the last we’ll see of the foldable rover. After all, he stuck with his two-wheel PCB motor design and eventually got that running pretty well. We’ll be keeping an eye out for progress on this one.

Continue reading “Single Flex PCB Folds Into A Four-Wheel Rover, Complete With Motors” →

Morse Code Clock For Training Hams

March 1, 2023 by Bryan Cockfield 13 Comments

It might seem antiquated, but Morse code still has a number of advantages compared to other modes of communication, especially over radio waves. It’s low bandwidth compared to voice or even text, and can be discerned against background noise even at extremely low signal strengths. Not every regulatory agency requires amateur operators to learn Morse any more, but for those that do it can be a challenge, so [Cristiano Monteiro] built this clock to help get some practice.

The project is based around his favorite microcontroller, the PIC16F1827, and uses a DS1307 to keep track of time. A single RGB LED at the top of the project enclosure flashes the codes for hours in blue and minutes in red at the beginning of every minute, and in between flashes green for each second.

Another design goal of this build was to have it operate with as little power as possible, so with a TP4056 control board, single lithium 18650 battery, and some code optimization, [Cristiano] believes he can get around 60 days of operation between charges.

For a project to help an aspiring radio operator learn Morse, a simple build like this can go a long way. For anyone else looking to build something similar we’d note that the DS1307 has a tendency to drift fairly quickly, and something like a DS3231 or even this similar Morse code clock which uses NTP would go a long way to keeping more accurate time.

Continue reading “Morse Code Clock For Training Hams” →