Microcontroller: Arduino and Raspberry pi Reliability

PLCs and industrial controllers are DESIGNED to operate machinery that is being used to make products and generate revenue. Arduinos and Raspberry Pi units are made for hobbyists. You get what you pay for.

When in doubt read response #1.

If still considering Arduino and Pi it is important to note that the Raspberry Pi has an operating system (on SD card) and an abrupt loss of power will cause a corrupted operation system (my guess is about 5% of the time). Circuits can be built to pull down an pin that executes a software shutdown but without the extra circuitry they can be a problem.

The Arduino does not have an OS and abrupt power loss does not cause problems.

I have used Arduino's to prototype several designs for medical equipment controllers but I wouldn't use them in a full blown product environment.

Commercial products generally need a robust specific design that is much more reliable than a hobby board. In other words design a custom pc board specifically designed for the application. Custom boards can often be cheaper in quantity, depending, of course, on marketing predictions.

Hooker

I agree with those posts above however, I still use them regularly.

When I need to build a piece of equipment (or alter an existing one) that will be used for a brief period of time or just a "one-off", I use Arduino boards.

Case in point...we have several remotely operated demolition machines and they are scheduled for a job at a client site. The client is concerned about potential damage to underlying steel, I built a simple Arduino device to sense when this condition is true and then execute a couple of minor functions to prevent the damage. I require four of these devices and it is likely that they will never be used again after the 5-day project at the client site.

Four units are certainly not enough for a production run, the operators are skilled and generally avoid the type of damage the client is concerned about (so device failure is not the end of the world) and spending thousands on something that will only see five days of use is a bit too rich for my employers.

These boards are great for hobbyist and prototypes, but suffer several problems when used as the base of a real commercial product. They almost always need additional circuitry to perform the desired tasks, and the interconnections and mounting issues from multiple circuit assemblies complicate the production process. Most importantly, the availability of the hardware is at the whim of the hobby marked, with new versions (different form-factors, connectors, peripherals) coming out each year. We are using a good alternative for our product, which started out as a Raspberry Pi prototype. The Raspberry Pi Compute Module (CM3) has the processor, RAM, HDMI, USB, and GPIO designed in to a board the size of a computer memory module. It plugs in to a 200-pin SODIUM memory socket on our board, interfacing to the rest of our custom circuitry and connectors. All of the hard work (signal integrity) for a quad-core processor and memory system is done on the CM3, leaving only the much simpler job of the custom I/O interfacing for our design work. We plug in a custom programmed SD memory card and the system is ready to go. The CM3 module is promised to be available for at least 6 years, addressing the hardware platform drift of hobby-market based designs.

Later,
Carl