Arduino MKR Makes Nespresso Monitoring Easy

April 25, 2021 by 23 Comments

Monitoring an appliance with a microcontroller usually follows a well-worn path of diving inside and finding somewhere in the electrical circuitry that can be connected through some kind of interface to a microcontroller. For his Nespresso pod coffee machine, [Steadman] eschewed tearing into the device, and instead chose to monitor the sound it makes. A commodity sound threshold sensor board is hooked up to an Arduino MKR Zero, and this set-up logs coffee consumption. It’s important to note how this generation of Arduino is no longer one of the simple boards of old, instead it sports an RTC and SD card alongside its SAMD21 Cortex-M0+ processor so it is perfect for just such a datalogging project. The coffee data can be saved into a CSV file viewable by a spreadsheet, for which code is provided.

We like this project for its non-invasive simplicity, and we can see that there could be plenty of other similar machines that could benefit from an analagous technique for non-invasive monitoring. While the pages of Hackaday are full of coffee machine projects we see surprisingly few pod coffeemakers, perhaps because our readers are a canny bunch who balk at paying a premium for their caffeine. If you do happen to have a Nespresso machine though, perhaps you’d like some help identifying the capsules.

An ESP32 Development Board For Sailors

April 25, 2021 by 8 Comments

[Matti Airas] wanted to have a better electronics platform for making his boat smarter, more connected, and safer. He found traditional marine electronics expensive and not suited for hacking and tinkering. There was also the issue of lack of interoperability between device generations from the same supplier and between different brands. This led him to design the Sailor Hat with ESP32 — a marine specific, open source hardware development board.

Applications include all kinds of sensor and control interfaces for the boat, such as measurement of fuel or water level, engine RPM, anchoring chain length counter, or setting up smart lighting or smart refrigeration control. The board is designed to work with the traditional NMEA 2000 standard, as well as with Signal K. NMEA 2000 is standardized as IEC 61162-3, but isn’t open source or free. Signal K, on the other hand, is free and open source, and can co-exist alongside NMEA 2000.

The marine environment can be pretty harsh with extremes of temperature, rain, humidity, condensation and vibration. Boats, just like automobiles, have a notoriously noisy electrical environment and [Matti] has paid special attention to noise and surge suppression throughout the board. The board can work with either 12 V or 24 V bus systems since the on board DC-DC converter is rated up to 32 V input. Connections between the board and the outside world need to be very robust, so it is designed to accept various types of connectors depending on how robust you want it to be.

The Sailor Hat is based around a standard ESP32-WROOM-32 module. Interfaces include a CAN bus transceiver, opto-coupled input and output, I2C, 1-wire and QWIIC interfaces, USB Micro-B programming conector, plus a couple of buttons and LEDs. All of the ESP32 GPIO pins are terminated on a GPIO header, with jumper options to disable terminations to the standard interfaces and instead route them to the GPIO header as needed. Additionally, there’s a generous prototyping area to add additional hardware to the board. Hardware design files are hosted on the project repository on GitHub.

On the software side, there are several frameworks that can be used, with PlatformIO, SensESP, ESPHome and Visual Studio Code being the recommended choices. Or you could use any of the widely available SDK’s for the ESP32 platform — Espressif SDK, Arduino Core for ESP32, MicroPython, NodeMCU or Rust.

[Matti]’s NMEA 2000 USB gateway example is a good way to get a grip on hardware assembly and software installation required to build a practical project using the Sailor Hat. The board is designed to withstand a harsh electrical environment. But it’s mechanical installation obviously requires greater care if it has to survive marine applications. The Sailor Hat can be installed in commonly available, 100x68x50 mm or larger plastic waterproof enclosures, rated for IP65 or higher. The bulkhead connectors and cable glands also need to be appropriately rated, and the enclosure may possibly need a IP68 rated ventilation plug to take care of environmental cycling within the enclosure.

Forth Module The Size Of A Stick Of Gum

April 25, 2021 by 27 Comments

Australian engineer [John Catsoulis] developed a small module called the Scamp2 dedicated to running Forth. The focus of his Udamonic project was not only to highlight Forth, but to make a module which was easy to use and doesn’t require any IDE on your computer. According to the website, these modules have found their niche in education as well as rapid prototyping for product development. His site has some good resources, including several Scamp/Forth example applications such as a model train controller or adding a real-time clock module.

The core of the module is a Microchip PIC24F64GB202 MCU with 64K Flash and 8K RAM. Of this, Forth takes up only 20K of Flash and 2K of RAM. [John] is using FlashForth, a version of Forth which came from [Mikael Nordman] at the University of Queensland almost ten years ago. FlashForth has been implemented on a wide variety of PIC and AVR ATmega processors and has apparently developed quite a following in Australia and elsewhere.

We estimate from the photo that the Scamp is about 80 mm long, just slightly longer than a standard piece of MIL-A-A-20175A Type II chewing gum ( 73 mm ). You can use it as-is, or with the header pins installed, the Scamp can be plugged into a breadboard for easy hacking. Regarding the interfacing of Scamp to other equipment, [John] says “Writing software to use other hardware is very easy, and fun.” We like his attitude.

Here is some more information from his Hackaday.io project page, and he also has a Tindie site. If you want a good overview of using Forth in embedded systems, check out Forth: The Hacker’s Language by our own Forth-guru [Elliot Williams]. Thanks to [Stephen Walters] for sending in the tip.

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Fertilizing Plants With A Custom 3D-Printed Pump

April 25, 2021 by 20 Comments

For all but the most experienced gardeners and botanists, taking care of the soil around one’s plants can seem like an unsolvable mystery. Not only does soil need the correct amount of nutrients for plants to thrive, but it also needs a certain amount of moisture, correct pH, proper temperature, and a whole host of other qualities. And, since you can’t manage what you can’t measure, [Jan] created a unique setup for maintaining his plants, complete with custom nutrient pumps.

While it might seem like standard plant care on the surface, [Jan]’s project uses a peristaltic pump for the nutrient solution that is completely 3D printed with the exception of the rollers and the screws that hold the assembly together. With that out of the way, it was possible to begin adding this nutrient solution to the plants. The entire setup from the pump itself to the monitoring of the plants’ soil through an array of sensors is handled by an ESP32 running with help from ESPHome.

For anyone struggling with growing plants indoors, this project could be a great first step to improving vegetable yields or even just helping along a decorative houseplant. The real gem is the 3D printed pump, though, which may have wider applications for anyone with a 3D printer and who also needs something like an automatic coffee refilling machine.

7000 RPM On A 3D-Printed Gearbox

April 25, 2021 by 17 Comments

[Steven] at the 3D Printer Academy has been working on a variety of different gear designs. He recently embarked on a series of experiments to see how fast he can spin a 3D-printed gearbox.

After testing several kinds of gear teeth, gear diameters, and gear spacing, he finally struck upon an 81:1 ratio gearbox. It has six gears: five stepped gears and one drive gear on the input shaft. First tests are accomplished with a 3D-printed handle, similar to a hand crank used to start really old cars. But unlike those cranks, [Steven]’s doesn’t have any release provision. While the handle can be removed, it can’t be removed while spinning.

We think it would be helpful to revise the drive shaft coupling method, allowing the handle or drill to be easily removed from the gearbox once it’s attained speed. This would be more convenient, and it seems prudent from the workbench safety point of view as well.

Example of a crank quick release mechanism

[Steven] manages to get the final gear spinning at 7000 RPM in video #2 of the series by hand cranking it “as fast as he can”, a speed measured by using the metronome app on his smartphone. He begins driving the gearbox with an electric drill in video #3, with some mixed but promising results. We think he will ultimately succeed in his goal of a high-speed, electric-drill-driven gearbox after a few more tests. If you want to have a go at this yourself, the design files are posted online.

How fast do you think he can eventually get this gearbox spinning? Are there any physical limitations of the assembly or due to the 3D printing materials/process? We certainly know that high torque can tear 3D-printed gearboxes apart, but how does the speed affect things? Let us know in the comments below.

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[Ken Shirriff] Picks Apart Mystery Chip From Twitter Photo

April 25, 2021 by 24 Comments

It’s no secret that the work of [Ken Shirriff] graces the front pages of Hackaday quite frequently. He’s back again, this time reverse engineering a comparator chip from a photo on Twitter. The mysterious chip was decapped, photographed under a microscope, and subsequently posted on the internet with an open call to figure out what it did.

[Ken] stepped up, and at first glance, it was obvious that most of the chip is unused, and there appeared to be four copies of the same circuit. After identifying resistors and the different transistor types, [Ken] found differential pairs.

Differential pairs form the heart of most op-amps, and by chaining them together, you can get a strong enough signal to treat it as a logic signal. Based on the design and materials, [Ken] estimates the chip is from the 1970s. Given that it appears to be ECL (Emitter-Coupled Logic), it could just be four comparators. But there are still a few things that don’t add up as two comparators have additional inverted outputs. Searching the part number offered few if any clues, so this will remain somewhat a mystery.

We’ve covered [Ken’s] incredible chip sleuthing before here, such as the Sharp EL-8 from 1969.

Was Novell’s NE2000 Really That Bad?

April 24, 2021 by 42 Comments

If you used almost any form of networked PC in the late 1980s or the 1990s, the chances are that you will at some point have encountered the Novell NE2000 network card. This 16-bit ISA card became a de facto standard for 16-bit network cards, such that very few “NE2000” cards were the real thing. A host of clones filled the market, some of which followed the spec of the original rather loosely. It’s something [Michal Necasek] examines as he takes the reader through the history of the NE2000 and why it gained something of a bad reputation. An interesting read for ’90s PC veterans who battled with dodgy Windows 3.1 network drivers.

The Novell line of network cards were not a primary product of the network server OS company but an attempt to spur the uptake of networked computers in an age when few machines were supplied from the factory with a network card installed. They were largely an implementation of the reference design for the National Semiconductor DP3890 Ethernet interface chipset, and for simplicity of interfacing and drivers they used an I/O mapped interface rather than DMA. The problem with the NE2000 wasn’t the card itself which would work with any NE2000 driver, but the host of “NE2000 compatible” cards that appeared over the decade as that magic phrase became a key selling point at the bottom end of the market. Sure they might contain a DP3890 or its clones, but even minor differences in behaviour would cause them not to work with all drivers, and thus they gained a bad name. The piece reveals the original card as one that might have been slow and outdated towards the end of its reign as a standard card, but maybe one not deserving of the ire directed at it.

If ancient networking kit is your thing, we’ve got some far more obscure stuff to show you.