Single Board COmputer

[Guest dudelove]

What is a single board computer. the Images show it as a card, does it go into some kind of display unit???.. I am newbie ...could somebody give me some explaination. thanks

[JimRowell]

An SBC is just a compact computer. No keyboard. No monitor. No drives. It's usually not an IBM compatible although that's quickly changing. Most of them are built around the Intel 8051 processor or competitive derivitives but there are lots of other popular ones too like the Rabbit (Z80), Hitachi and 6500 stuff. Usually 8-bit or 16-bit. There are now quite a few that are built with 486 or pentium chips. Basically if you add I/o modules and an operating system to it, and put it in a box, you have a PLC. Most are programmed using C. Some have an on-board BASIC available. Some have their own control oriented language. Some people program them directly in Assembler. They come with a host of features built in but the available I/O is usually logic level and requires interfacing to use. Many OEM's use them rather than PLC's since they can be very affordable especially in quantity, very compact and offer very high performance. They are usually not a ready-to-go solution like PLC's are nor are they always as robust as PLC's (but they can be). Jim Rowell

[Guest dudelove]

So if I were to use the BL1800 Jackrabbit SBC, and program it to talk to serial devices, I will have to use one of the operator interfaces, so as to allow the operator to interact with the program loaded in the rabbit.

[JimRowell]

That's correct unless the BL1800 is different then any others I've seen. The situation is no different than it is with a plc. You have to provide some external method for user interaction such as a PC or a self-contained HMI display (or lights & buttons or whatever). You could consider some of the low-end lcd displays. Some of those even have built-in buttons or allow connection of cheap keypads. Connection to the sbc is serial or usb. You can be up and running for between $70 to 200.00 (plus the sbc, enclosure, etc). Try MatrixOrbital. The Jackrabbit is very respected although I'm not personally familiar with it. All sbc's come with at least one if not several serial ports, pwm, ADC, DAC, etc, etc. Fairly complete packages. Usually they have exceptional support software including debugging facilities that far surpass anything you'll find in a plc. On the other hand, because of the sophistication of some of the systems, you need all the help you can get. If you want low price and a very good setup for beginners, you could check out the Pic stuff. It's not very sophisticated but it's used in a lot of consumer products and is fairly capable. Has a simple instruction set. Fast and cheap. There are many sbc's based on it. The most well known for Pics is Pallalax. Their boards are smaller than credit cards. You could also try BasicMicro. Jim Rowell Edited March 14, 2004 by JimRowell