SBC for DAQ - Suggestions?

Mark

There are plenty of companies like ourselves that could build you up something albeit at a cost. In an ultra-light aircraft your power supply/comsumption and even the mass of the boards may cause you a weight problem so be careful of whatever solution you go for. Some of our products have been doing a different processing and logging type as part of a customer design on model helicopters -

It would also be worth having a detachable display for flight assuming you don't need it then to keep the mass down.

Do you need to store data or are you planning to transmit that to a ground station as it is collected?

John Adair Enterpo> I want to build a device to capture engine performance (eg rpm, oil

John

Thanks for the reply.

The type of airplane I am thinking of weighs between 700-1200 pounds gross, so a couple of pounds of instrument isn't that critical. The device will have on-board display (maybe 5 inch TFT LCD) and run off the aircraft's 12 volt DC electrical system. The data logging requirement will be minimal, so removable storage media is an optional extra.

Any further thoughts?

MarkSix.

Assuming you don't have someone do the whole package for you, you probably want to go with a PC-104 stack. You can get a single board computer that's PC compatible and will talk to a 1/4-VGA display (or you could get a VGA-format display for greater compatibility), and there's a large choice of DAQ boards to go with it.

You _will_ need some software to bolt it all together, though, and unless you're planning on learning how to write this software, you may want to find someone who wants to do the whole shebang for you.

You need both. You need a powerful SBC for the display side and a dedicated uC for the data side. Some time ago, we made some AVR boards with 8 channel A2D and RS232 talking to the SBC (or PC). The uC logs data periodically and upload to the SBC in burst.

The customer disappears so we never follow-up on it. I still have 80 prototype boards available, if you want some of them.

Please tell us more; how much? Loaded with firmware and a blurb on how to use?

Michael

Second board of:

1. Atmega649 (64K flash, 2K sram, 1K eeprom)
2. Max2232 driver
3. Analog multiplexer from 2 to 8.

These boards might be suitable if the uC could continually cycle through the 8 data inputs and send them to the SBC to update the display in realtime. Like the speedo gauge in an auto.

But like Michael asked -

Please tell us more; how much? Loaded with firmware and a blurb on how to use?

MarkSix

Mark

That opens up your choices a lot. Assuming you have a reasonable current capability you can have effectively a PC on board if that is what you need. As mentioned elsewhere PC104/PC104+ is a good format for what you are doing. It's generally very robust. We have had some of Hollybush1 (PC104+/PCI104) products flying in real full sized helicopters and mechanically the customer on that had few problems as far I know. You do have to be careful of the vibration environment whether in a full sized aircraft or model size as has been done with our Darnaw1 product as mentioned in the previous post.

Being basied the sort of thing I would suggest with our products would be to use a Hollybush1, or even better a sister product that we are just about to launch, as processor element. I would either then buy PC104/PC104+ boards to fill the gaps in the requirements and if really necessary do a simple mezzanine board to fit on our Hollybush1. There are lots of other possibilities I could offer but without a lot more background on your aims and requirements and your budget for that matter it is difficult to give a 100% answer as to what is best.

John Adair Enterpo> John

It's just a matter of programming. One A2D input is monitoring the power supply voltage. Two of he A2D inputs are routed to an analog multiplexer selected by two port pins (2 out of 8). The inputs (buffered and protected by the multiplexer) are routed to a 10 pins header (8 + power & ground). Of course, you can disable Jtag (six pins header) and get 4 more analog inputs.

During testings, we cycle through eight channels and pump it out to RS232 every few seconds. The uC speeds up (receiving +) or slows down (receiving -) according to RS232 commands from the host.

The LCD signals (20x4) are routed to a 30 pins extra wide dip header.

Probably $10 to $15 ea, depends on how much more work need to be done.

Possible.

John,

Maybe I should write a design specification and send it to you offline for your consideration?

MarkSix

Linnix, Linnix,

The boards sound interesting and I may be able to take all of them off your hands if this works out. Maybe I should write a design specification and send it to you offline so you can advise how much more work needs to be done to the boards to make them suitable for my needs.

MarkSix

Linnix,

Could you please send me your email address so I can give you the design specification offline?

MarkSix

John,

Could you please send me your email address so I can give you the design specification offline?

MarkSix

Mark

If send anything to boardsales at our route address of enterpoint.co.uk and mark it for my attention it will be routed to me. The amount of spam we get on any published email address precludes me publishing a direct address in a public forum.

Regards John Adair

Emailed to MarkSix at yourdomain

There is also a contact me form at the bottom of