Hackaday Links: November 15, 2015

There are a surprising number of Raspberry Pis being used in industrial equipment. This means the Arduino is left behind, but no longer. There’s your PLCs that use Arduinos.

A few weeks ago, Google introduced a machine intelligence and computer vision technique that made the world look psychedelic. Now, this library is available. On another note, head mounted displays exist, and a sufficiently creative person could mash these two things together into a very, very cool project.

Welcome to Kickstarter! Kickstarter is an uphill battle. People will doubt you because you don’t have a ‘target audience’ or ‘the rights to this franchise’ or ‘any talent whatsoever’, but that’s what crowdfunding is for!

Several years ago, Apple shipped a few million 17″ iMacs with defective displays. They’re still useful computers, though, especially if you can find a replacement LCD. Apple, in all its wisdom, used a weird connector for this LCD. Here’s the adapter board, and this adapter will allow displays running up to 1920×1200.

[Jan] has earned a reputation of building some very cool synths out of single ARM chips. His previous build was a Drumulator and now he’s shrinkified it. He’s put four drum sounds, pitch CV, and audio out on an 8-pin DIP ARM.

YouTube gives you cadmium! [AvE], recently got 100,000 subscribers on his YouTube channel. Apparently, YouTube sends you a terrible belt buckle when you manage to do that. At least he did it without playing video games and screaming.

13 thoughts on “Hackaday Links: November 15, 2015

  1. It’s impressive they put Arduino hardware in a PLC format, but going off their specifications, they aren’t even suitable for a my first PLC style learning experience. No ladder code for starters, the one perhaps major defining trait of PLCs. Leave out ladder in any form and you have an Arduino (or a Pi) in a souped up case. The outputs support DC input and analog voltage input only. As far as any industrial environment I’ve been in goes, analog sensors using voltage are dead and gone except in the most obstinate of legacy applications (I get your modicon still works, but it’s held together with more bailing wire than actual wires, and where will you get parts when it breaks again?) and they have been replaced by 4-20mA sensors. A PLC that can’t interface with analog current sensors, either alone or through an analog input module has essentially no use as it can’t interface to any slightly modern sensor. As far as other essential features, it has no specifications of power fluctuation resistance, voltage and current limits of inputs and outputs, user replaceable terminal blocks, input and output optoisolation, or if it’s sink, source, triac or relay.
    They seem to be a standard Arduino with the raw inputs and outputs exposed without isolation and stuck into a DIN mountable case.
    At this price anyone looking to experiment with PLCs would be better off buying a used micrologix from Ebay for a similar or lower cost. Even a FX-2N series would be far better, and Mitsubishi is near bottom of the barrel for PLC hardware.

    1. 4-20 input is easy, just pick your appropriate bridge resistor. Output, not so much. You’d need a voltage controlled current source with short circuit proofing. Anyway, it’s nice enough to survive the IO side of stuff, but one reason you don’t write directly to PLC hardware is that there’s a lot going on with CRC and other checks to make sure it doesn’t act erroneously. That’s why most code runs virtually, so the system can do the Class B safety checks and memory tests required.

      I looked at their manual for the Ethernet variations and it looks like very basic isolation was observed, but I don’t think they even implemented basic reverse polarity protection on the power input, despite accepting 12-24VDC power. I’m also curious how this matches against CE marking, and what’s going to happen when they find out the hard way about self CE marking rules.

      I’d want to see the schematics given the exposed SPI and I2C connections. Frankly, I like the idea, but not for industrial applications that deal with anything that can harm someone or catch fire. It would be better to market to the hobbyist trying to interface a surplus industrial sensor into their existing system. Someone cracked open a Smart Relay and decided to make their own.

    2. You are showing your age…while IEC-61131 supports ladder, FBD seems to be more popular for new implementations, especially if you are doing anything involving analog.

      However I must agree with the rest of your post – this seems like it might be applicable to lab or prototype use, but not as a production PLC.

      Keep in mind when buying used PLCs, that the programming software is a significant expense on top of the hardware.

      1. >> …FBD seems to be more popular for new implementations…
        Maybe that depends on your industry and maybe locale. From what I see, packaging equipment in North America is by far mostly ladder. (that doesn’t necessarily mean I like it though).
        We have customers that specify it, and get upset when they find our standard software also includes ST where appropriate. I’ve only used FBD for processing and/or PID applications.

  2. I recently received one of these “arduino plc’s” and it does have actual relay outputs, PWM, and isolation, however no analog outs or 4-20 (0-10v + 500 ohm resistor will get you there though) In all not a bad unit for basic plc type stuff but with arduino programming. (please anything but ladder…)


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