the raspberry PI at the core of a future machine?

[ODM]

One important thing which is usually left undescribed when introducing microcontroller driven MD projects is the algorithm(s) used by the microcontroller. Often it is possible to adapt the sampling etc. for another microcontroller, if one has such parts in their leftover shelf - the programming hardware and some experience, as well.

If the timing and/or digital integrator/filter values are described, it's not difficult to adapt the control software. Like mentioned earlier, some microcontrollers might be hard to get from some suppliers, and parts generally become obsolete over time, so .hex files alone will usually become useless unless someone wants to reverse assemble them.

Schematics are easy, as they're adaptable for different components and package footprints, but software and the underlying methods are still poorly documented with most projects - even if the generic sampling integrator PI and phase demodulation VLF techniques are well documented, and on that basis most of the popular microcontroller driven MD projects are reasonably straightforward (if time-consuming) to convert.

[Aziz]

Arduino Due

http://arduino.cc/en/Main/ArduinoBoardDue

Nice board.
Aziz

PS:
Price: €39.00

VAT not included

[bklein]

Any thoughts on the just released Raspberry Pi 2?

[der_fisherman]

As I believe it actually uses generally less power, it obviously has some possibilities, as power usage is often the deciding factory for portable applications....but I will defer to any experts here of course.....
regards

[greylourie]

I see Windows is using this as a means to try get into the market taken over by Android. You can get a version of Win10 free for your raspi2.

For metal detector use, this seems to need a lot of battery. 0.8A @ 5V.
And what are you going to do with it ? What would be its greatest strength over using simpler microprocessors ? Processing signal to audio ? Discerning noise from target ? As a controller and interface for the REAL hardware ? Good for a tinkerer, and someone familiar with writing computer software. Good for an experimental platform.

Theres some older boards using Allwinner chips, too. A good platform to look for would be something using one of the Chinese chips developed for mobile phones. Then you are getting into more worthy battery consumption stats. Mediatek comes to mind. ( Eat your hearts out iphone/samsung fanboys. ) The only problem is they rush to produce chips with ever increasing capabilities, good for the demands of a rapidly changing mobile phone market. But not good for makers, tinkerers and other hobbyists. A chip/soc is here today, replaced tomorrow.

Raspi2, good for tinkering with. But what real improvement can it add to a metal detector project ? Especially an coil+stem+box project ?

[sinclairuser]

while i was laid up recently the couple of raspi's i had were the only projects i had in the house, i built an emulation box to play my favourite retro games(raspi "B" 512), and a raspi "A" the smaller one i have been playing with an adafruit 3.5 screen and my modded barracuda pi, i have been teaching myself python, but the raspi is useless.

the gpio's are not sophisticated enough to drive the detector, so its basically an add on display, which is no more use on a barracuda than the vco mod it has already.
so the "a" model with a 3.5 colour screen, while being useless for a pulse induction, may make a great vdi for a VLF, the right coder could write an excellent script( just not me!).

with the mame box finished and me being back to full health, the barracuda experiment has been dumped in favour of my half built mini pulse, but once the MP is finished i may try again with the IDX, it has scope for a great vdi, as allways with these things its the code where it gets tricky.

[golfnut]

Im in the process of converting a large ride on mower with 10kW 3phase petrol mains generator.

My local college gave me an old CRAY computer, it even predicts the weather.. - 10Giga Flops - wow, out there..


Im planning a 24" monitor with gaming virtual universe, for when there are just too-few targets.


Best of all it levitates on a cold plasma vortex.

Alain from xp is ringing the phone off the wall.
Bruce is on beta blockers.

I surprise even myself.

But alas, like most other machines. it will still only do 8" in the ground on a medium size coin!!

[golfnut]

there was a batch made, maybe in china, a long time ago, where the soldering was not reliable - people had trouble getting their projects to run perfectly.

The production was moved to another place and the errors were resolved.

I think they are good now.

[Daren]

I did a project with Raspberry (house monitoring with SMS connectivity), the problem with them is that you need to do the proper system shutdown or your SD card will get corrupted. They don't have eeprom. I have OS mounting SD read only, I turned off all linux logs, still I got corruptions. There are other boards with eeprom that don't require shutdown you can just remove power example could be PCDruino and I think beagebone also can be just turned off and does not require linux shutdown.
If I did the house monitoring again I would use microcontroler and not raspberry.
I don't see why would you need raspberry speed....

[greylourie]

Alain from xp is ringing the phone off the wall.

Actually that was me on the phone. Can I have my VR goggles back please.

[bklein]

What is the specific issue with the GPIO on the rpi?
Why would it be so crippled?
Would the ST32m4 Discovery board have the same problem?
Weird that such a "powerful" card would continue to have such limitations...

Check here:
http://codeandlife.com/2012/07/03/be...pi-gpio-speed/
what's the issue?

[Daren]

You have linux OS running on this board, to access the io you will need to make IO call that will switch from user space to kernel and perform the actual operation. On the microcotroler you will have to do only one register write.
In my opinion any application what require real time operation (such as MD) is much more suitable for microcontroler. You probably could put real-time version of linux on rpi board that will let you control more of the responsiveness to the interrupts, buy you will be writing a lot of code to achieve what is given in microcontroller world for free.
Another aspect is that in uC you can find most info in one manual, for rpi / linux you will need to interact with a lot of software not all of it well documented.

[Davor]

One undocumented thing I find extremely annoying is power consumption of these boards.

[sinclairuser]

One undocumented thing I find extremely annoying is power consumption of these boards.

heavy, a 2 amp power supply is recommended if you intend to run keyboard, mouse, wifi dongle and built in screen header,a couple of tits over on the raspi forum suggested 1 amp is all you would ever need, but that's wishfull thinking, my game setup needs the two amps.

they are power hungry when running lots of peripherals, but the A model running the small screen is capable of running on batteries, the stumbling block is its stupid operating system, and its shutdown procedure as has been pointed out allready.
the corruption of the sd card is a worry, the more you think about it the more incompatible the raspberry pi gets, one of the microcontroller boards is nearer to where we need to be.

[sinclairuser]

this is what the raspi excels at, not running a metal detector .