Which Microcontroller Is Best Microcontroller?

Let’s say you’re working on a project, and you need a microcontroller. Which chip do you reach for? Probably the one you’re most familiar with, or at least the one whose programmer is hiding away in a corner of your desk. Choosing a microcontroller is a matter of convenience, but it doesn’t have to be this way. There are dozens of different ARM cores alone, hundreds of 8051 clones, and weirder stuff including the Cypress PSoC and TI’s MSP430. Which one is best? Which microcontroller that costs under a dollar is best? That’s the question [Jay Carlson] tried to answer, and it’s the best microcontroller shootout we’ve ever read.

[Jay] put together a monster of a review of a dozen or so microcontrollers that cost no more than a dollar. Included in this review are, from Atmel: the ATtiny1616, ATmega168PB, and the ATSAMD10. From Cypress, the PSoC 4000S. From Freescale, the KE04 and KL03. Holtek’s HT-66, and the Infineon XMC1100. From Microchip, the PIC16, PIC24, and PIC32. From Nuvoton, the N76, and M051. The NXP LPC811, Renesas RL-78, Sanyo LC87, and Silicon Labs EFM8. ST’s STM32F0 and STM8. STCMicro’s STC8, and finally TI’s MSP430. If you’re keeping score at home, most of these are either ARM or 8051-style cores, but the AVRs and PICs bump up the numbers for ‘proprietary’ core designs.

This review begins the same as all tech reviews, with a sampling of tech specs. Everything is there, including the amount of RAM to the number of PWM channels. [Jay] is going a bit further with this review and checking out the development environments, compilers, dev tools, and even the performance of different cores in three areas: blinking bits, a biquad filter, and a DMX receiver. There’s an incredible amount of work that went into this, and right now, this is the best resource we’ve seen for a throwdown of microcontrollers.

With all this data and the experience of going through a dozen different microcontroller platforms, what’s [Jay]’s takeaway? The STM32F0 is great, the Atmel/Microchip SAM D10 has great performance but you’ll be relying on some third-party libraries. The pure Microchip parts — the PIC16, PIC24, and PIC32 — have infinite product lifetimes, a wide range of packages, and a huge community but use a clunky IDE, and expensive compilers. The Cypress PSoC was just okay, and the PSoC5 or PSoC6 would be better. Surprises from this test include the Renesas RL-78 and its high performance, low cost, and the most power-efficient 5V part in the test.

With all that said, what’s the best microcontroller? That’s a dumb question, because the best microcontroller will always be the best microcontroller for that application. Or whatever you have sitting around in the parts drawer, we were never quite clear on what the answer actually is. That said, this is a new high water mark for microcontroller reviews, and we hope [Jay] will continue his research into microcontrollers that cost more than a dollar.

Go From Resin Caster To Resin Master

When it comes to resin casting, time is of the essence. It helps to gather everything you’ll need and have it within reach before starting. But if you don’t know what you don’t know, it can be difficult to anticipate needs. Luckily, [Botzen Design] has a few tricks up his sleeve that will save time, materials, and sanity for novices and old hands alike.

It may seem somewhat obvious to mix up resin in a disposable or reusable plastic cup. But not all cups are created equal. Polypropylene cups won’t outgas into your resin, but polystyrene will. If you use a silicone cup or any polypropylene food container marked #5/PP, cured resin will peel cleanly off of the cup walls.

For some reason, the giant jugs of resin [Botzen Design] uses don’t come with pumps. How do they expect someone to meter out exact amounts of resin and hardener while pouring them out of gallon jugs? Stadium-style condiment pumps at a restaurant supply store make things much simpler while avoiding costly spillage.

Our favorite tip (and seemingly [Botzen Design]’s as well) is the drip hammer. When air bubbles mature into craters, they can be filled easily and precisely with a drop or two of wet resin. A pipette would probably just get clogged, but an icicle of cured resin hanging from a stick makes the perfect drip applicator.

Want to get into resin casting but don’t know where to start? Hackaday’s own [Gerrit] has you more than covered.

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Build A Calculator, 1974 Style

Last month we touched upon the world of 1970s calculators with a teardown of a vintage Sinclair, and in the follow-up were sent an interesting link: a review of a classic Sinclair calculator kit from [John Boxall]. It’s a few years old now, from 2013, but since it passed us by at the time and there was clearly some interest in our recent teardown, it’s presented here for your interest.

It seems odd in 2017 that a calculator might be sold as a kit, but when you consider that in the early 1970s it would have represented an extremely expensive luxury purchase it makes some sense that electronics enthusiasts who were handy with a soldering iron might consider the cost saving of self-assembly to be worthwhile. The £24.95 price tag sounds pretty reasonable but translates to nearly £245 ($320) in today’s terms so was hardly cheap. The calculator in question is a Sinclair Cambridge, the arithmetic-only predecessor to the Sinclair Scientific we tore down, and judging by the date code on its display driver chip it dates from September 1974.

As a rare eBay find that had sat in storage for so long it was clear that some of the parts had suffered a little during the intervening years. The discrete components were replaced with modern equivalents, including a missing 1N914 diode, and the display was secured in its flush-fitting well in the board with wire links. The General Instrument calculator chip differs from the Texas Instruments part used in the Scientific, but otherwise the two calculators share many similarities. A full set of the notoriously fragile Sinclair battery clips are in place, with luck they’ll resist the urge to snap. A particularly neat touch is the inclusion of a length of solder and some solder wick, what seems straightforward to eyes used to surface-mount must have been impossibly fiddly to those brought up soldering tube bases.

The build raises an interesting question: is it sacrilege to take a rare survivor like this kit, and assemble it? Would you do it? We’d hesitate, maybe. But having done so it makes for a fascinating extra look at a Sinclair Cambridge, so is definitely worth a read. If you want to see the calculator in action he’s posted a video which we’ve put below the break, and if you need more detail including full-resolution pictures of the kit manual, he’s put up a Flickr gallery.

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Roll Your Own JBC Soldering Station

[Marco Reps] was soldering some boards with a lot of thermal mass and found his usual soldering iron was not up to the task. He noticed some professional JBC soldering stations that he liked, but he didn’t like the price. Even an entry-level JBC station is about $500 and they go up from there. He decided to build his own, but it did take awhile to complete. You can see two videos about the project, below.

How can you build your own soldering station and still claim it is a JBC? [Marco] noticed that the real performance of the iron came from the tip — what JBC calls a cartridge. In addition, the handle provides good ergonomics. You can buy the tips and handles from JBC for considerably less than a complete station. You just have to add the electronics to make it all work.

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3D Printed Hovercraft Takes To The Air

Instructables user [John_Hagy] and some classmates built an RC hovercraft as their final project in the Robotics Education Lab at NC State University. It’s a foam slab with a Hovership H2204X 2300Kv brushless motor inflating a skirt made out of ripstop nylon. Nylon is great here because it has a low friction coefficient and is nonporous to keep the air in. A second motor propels the craft, with a servo turning the whole motor assembly to steer. The team designed and 3D-printed fan holders which also help channel the air to where it’s supposed to go. Control is via a typical radio-control transmitter and receiver combo.

The project writeup includes a lot of fun detail like previous versions of the hovercraft as well as the research they undertook to learn how to configure the craft — clearly it’s their final paper put on the internet, and well done guys.

Needless to say, we at Hackaday can’t get enough of this sort of thing, as evidenced by this cool-looking hovercraft, this hovercraft made on a budget and this solar-powered ‘craft.

Trainspotting With Junk, For Science

[Douglas] hometown Goshen, Indiana takes the state’s motto ‘The Crossroads of America’ seriously, at least when it comes to trains. The city is the meeting point of three heavily frequented railroad tracks that cross near the center of town, resulting in a car-traffic nightmare. When everybody agrees that a situation is bad, it is time to quantify exactly how bad it is. [Douglas] stepped up for this task and delivered.

High tech train counting equipment

He describes himself as cheap, and the gear he used to analyze the railroad traffic at a crossing visible from his home certainly fits the bill: a decades-old webcam, a scratched telephoto lens and a laptop with a damaged hinge.

With the hardware in place, the next step was to write the software to count and time passing trains. Doing this in stable conditions with reasonable equipment would pose no problem to any modern image processing library, but challenged with variable lighting and poor image quality, [Douglas] needed another solution.

Instead of looking for actual trains, [Douglas] decided to watch the crossing signals. His program crops the webcam image and then compares the average brightness of the left and right halves to detect blinking. This rudimentary solution is robust enough to handle low light conditions as well as morning glare and passing cars.

The rest is verifying the data, making it fit for processing, and then combining it with publicly available data on car traffic at the affected intersections to estimate impact. The next council meeting will find [Douglas] well prepared. Traffic issues are a great field for citizen science as shown in Stuttgart earlier. If the idea of bolting old lenses to webcams intrigues you, we got you covered as well.

Hackaday Prize Entry: A Mess Of VGA On A Breadboard

Before all our video games came over the Intertubes, before they were on CDs, and before they were on cartridges, video games were all discrete logic. Pong was the first and you can build that out of several dozen logic chips. The great [Woz] famously built Breakout out of 44 simple chips.

For [Marcel]’s entry to the Hackaday Prize, he’s taking the single board microprocessor-less computer to the next level. He’s building a multi-Megahertz 64-color computer on a breadboard. What’s the capacitance of a breadboard? Just ask [Marcel].

The design of this disintegrated computer has just about everything you could want in a discrete CPU. There is no microcontroller or complex chips like the 74181 ALU, there’s pipelining with sometimes two instructions per clock, decoding with diodes, and a 60 Hz, 64 color VGA output and four sound channels. There’s only about 40 TTL chips on this board.

The project logs for this Hackaday Prize entry are a treat in themsleves, ranging from topics to the implementation of NES controllers to getting rid of the breadboard and turning this computer into something like a vintage game system, but with a custom CPU and instruction set. It’s an amazing build, and an awesome project for the Hackaday Prize.

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