Planet Arduino

When teaching Industrial Automation to students, you need to give them access to the things they will encounter in industry. Most subjects can be taught using computer programs or simulators — for example topics covering PLC, DCS, SCADA or HMI. But to teach many other concepts, you  need to have the actual hardware on hand to be able to understand the basics. For example, machine vision, conveyor belts, motor speed control, safety and interlock systems, sensors and peripherals all interface with the mentioned control systems and can be better understood by having hardware to play with. The team at [Absolutelyautomation] have published several projects that aim to help with this. One of these is the DIY conveyor belt with a motor speed control and display.

This is more of an initial, proof of concept project, and there is a lot of room for improvement. The build itself is straightforward. All the parts are standard, off the shelf items — stuff you can find in any store selling 3D printer parts. A few simple tools is all that’s required to put it together. The only tricky part of the build would likely be the conveyor belt itself. [Absolutelyautomation] offers a few suggestions, mentioning old car or truck tyres and elastic resistance bands used for therapy / exercise as options.

If you plan to replicate this, a few changes would be recommended. The 8 mm rollers could do with larger “drums” over them — about an inch or two in diameter. That helps prevent belt slippage and improves tension adjustment. It ought to be easy to 3D print the add-on drums. The belt might also need support plates between the rollers to prevent sag. The speed display needs to be in linear units — feet per minute or meters per minute, rather than motor rpm. And while the electronics includes a RS-485 interface, it would help to add RS-232, RS-422 and Ethernet in the mix.

While this is a simple build, it can form the basis for a series of add-ons and extensions to help students learn more about automation and control systems. Or maybe you want a conveyor belt in your basement, for some reason.

Industrial hardware needs to be reliable, tough, and interoperable. For this reason, there are a series of standards used for command & control connections between equipment. One of the more widespread standards is ModBus, an open protocol using a master-slave architecture, usually delivered over RS-485 serial. It’s readily found being used with PLCs, HMIs, VFDs, and all manner of other industrial equipment that comes with a TLA (three letter acronym).

[Absolutelyautomation] decided to leverage ModBus to control garden variety digital cameras, of the type found cluttering up drawers now that smartphones have come so far. This involves getting old-school, by simply soldering wires to the buttons of the camera, and using an Arduino Nano to control the camera while talking to the ModBus network.

This system could prove handy for integrating a camera into an industrial production process to monitor for faults or defective parts. The article demonstrates simple control of the camera with off-the-shelf commercial PLC hardware. Generally, industrial cameras are very expensive, so this hack may be useful where there isn’t the budget for a proper solution. Will it stand up to industrial conditions for 10 years without missing a beat? No, but it could definitely save the day in the short term for a throwaway price. One shortfall is that the camera as installed will only save pictures to its local memory card. There’s a lot to be said for serving the images right to the engineer’s desk over a network.

We’ve seen [Absolutelyautomation]’s work before – check out this implementation of Pong on an industrial controller.