Convenient microcontrollers for PI project wanted.

[Aziz]

Hi friends,

I am searching for convenient microcontrollers (µC) for a new PI project. Which µC gives a best performance on:
- cheap and easy to get
- low power consumption
- high processing speed (>10 MIPS)
- less pins
- free software development tools (assembler, c-compiler, etc.)
- cheap programming tools
- well documented (specs, application notes, examples)

As far as I found, the Atmel's ATtiny2313 is my personal favorite. Do you know other µC? I am familiar with the complete Atmels µC family. Other companies and platforms could also be interesting to check.

Aziz

[1843]

Hi there,

I specially use mega8 and obtain it easily for a low price(~$02). It can be run at 16MHz...but has 28pins....Isn't suit for you?

Regards
1843

[Aziz]

Hi 1843,

I know the ATMega8/16/32 series. It has lots of features, which most of them are really not required and will consume much power. The ATtiny2313 would probably be enough for the timing logic and some features. All the other stuff can be made in conventional analog manner. It will be operated at 20 MHz and if possible with up to 10 k pulses per second (PPS). And it cost's only ~2$ and has only 20 pins. The power consumption is excellent low. One or two of them could be used in a project.

Regards,
Aziz

[1843]

The tiny2313 has a low flash... I think that AT89C4051 (20-Pin 24MHz 4kb) is far better.

Regards
1843

[Unregistered]

The Tracker PI uses the 90S2313, the hole circuit uses ca 50 mA at 12 volt.

[Max]

Hi friends,

I am searching for convenient microcontrollers (µC) for a new PI project. Which µC gives a best performance on:
- cheap and easy to get
- low power consumption
- high processing speed (>10 MIPS)
- less pins
- free software development tools (assembler, c-compiler, etc.)
- cheap programming tools
- well documented (specs, application notes, examples)

As far as I found, the Atmel's ATtiny2313 is my personal favorite. Do you know other µC? I am familiar with the complete Atmels µC family. Other companies and platforms could also be interesting to check.

Aziz

Hi,
I think you knows already the answer: Atmel chips offer about everything you need. Personally I would like an ATmega8 as minimum, though consumption is higher than tiny2313.

If you want >10MIPS stuff you sure wanna implement some disc stuff inside the uC, otherwise why ? Any PIC will do the timing required for a PI !

Still now, Atmel has very nice products, low cost stuff with hi performances... sure not DSP in mega8 or 2313 but which are real alternatives ? PICs ? no way...

The others... like AD stuff are rare parts... costs too much... so will not fit your requirements.

I think Scenix stuff will fit too... but then you'll get troubles about development platform.

Kind regards,
Max

[hobbes_lives]

I'm currently working with the dsPIC30F series of Microchip DSCs and like them quite well. They're 16bit devices that can run at 30 MIPS, and have a good array of built in peripherals.

Microchip offers MPLab as a free IDE. You have the choice of developing code in C or assembly.

Here's a link to their array of dsPIC30F devices:

http://www.microchip.com/ParamChartS...g=en&pageId=75

[Aziz]

The tiny2313 has a low flash... I think that AT89C4051 (20-Pin 24MHz 4kb) is far better.

Regards
1843

I think, 2 kBytes are big enough for the simple timing logic code.
There are more other interesting chips from Atmel:
http://gibibit.com/electronics/AVR%2...on%20Table.pdf

Some of very small ATTiny-chips with 8 pin DIL/SOIC could also be used just for very simple tasks additionally. And they also cost ~2$ and will operate up to 20 MHz.

I have checked the PIC-family from microchip and would not like to use these chips.

Aziz

[Aziz]

The Tracker PI uses the 90S2313, the hole circuit uses ca 50 mA at 12 volt.

Yes, this is the former version of ATtiny2313. It is one of the most used µC and easy to get. This is the reason, why I like the ATtiny2313.

Aziz

[TheWizard]

PIC24Fxxxx 16 MIPS
- 16 bits MCU

- cheap and easy to get - [ FREE SAMPLES ]
- low power consumption - [ in SLEEP ~4 uA ]

- high processing speed - [ 16 MIPS ]

- less pins - [min 28 pins, Have Pin Remaps, QFN, DIP, SOIC, SOP ]
- free software development tools (assembler, c-compiler, etc.) [ + ]
- cheap programming tools - [ + ]
- well documented (specs, application notes, examples) [ + ]

Aziz

[Aziz]

As I have collected lots of experiences with complex µC and DSP projects (16/32-Bit, huge amount of MIPS, ARM6, ARM7, ADSP-2181, etc.), I like to have a really simple to use µC project.

I could imagine to use the ATMega8 chip as the maximum complexity chip. But I tend to use a simple and cheap one and maybe several of them if necessary.

The microchip µC's are also quite convenient - but the development tools are much more expensive to me (I am a very poor man! ).

Look at the ATtiny13, ATtiny15, ATtiny24/44/84, ATtiny25/45/85, they have only 8 - 14 pins.

I will wait to the end of the month before I can order some samples.

Are there some low complexity high performance DSP chips available today?

Regards,
Aziz

[Max]

As I have collected lots of experiences with complex µC and DSP projects (16/32-Bit, huge amount of MIPS, ARM6, ARM7, ADSP-2181, etc.), I like to have a really simple to use µC project.

I could imagine to use the ATMega8 chip as the maximum complexity chip. But I tend to use a simple and cheap one and maybe several of them if necessary.

The microchip µC's are also quite convenient - but the development tools are much more expensive to me (I am a very poor man! ).

Look at the ATtiny13, ATtiny15, ATtiny24/44/84, ATtiny25/45/85, they have only 8 - 14 pins.

I will wait to the end of the month before I can order some samples.

Are there some low complexity high performance DSP chips available today?

Regards,
Aziz

Hi Aziz,
consider also you could use AVR-gcc with Atmel's... something you will not find for others... you need licenses for real products on the PIC arena... e.g. the BKnudsen Data compiler CC5X etc have free versions but with severe limitations on memory usage, so free version is about useless on "real" stuff.
Same apply to other compilers... though Microchip claim the free software is available... this is pretty naive assertion cause just bits of code are truly for free : when you enter the professional development you need program them in assembly to get for free... or just buy licences for good brand compilers for C development.
The same story apply to DSPic and others... exactly as with low end / obsolete / academic products like 16F84 or 16F628 chips.

Think also at programmers... don't you need one too ? The PIC programmers are easy... but try to integrate one for ISP using existent software... it's a mess... and routine could be everytime you change a bit... to make a number of step to get your device programmed, NO GOOD. The advantages of Atmels are clear about this... if you get e.g. WinAVR you get also AVRdude command line programmer and you just add a line in makefile... and everytime you hit make you make/compile and download code into the AVR chip: save time, save work, save money (don't need to buy different software to do this)

You can find ATmega8 for some eur , maybe 2-3eur each now , so you'll not waste money this way and got 16MIPS for about FREE!

Which is the cost of PIC24 series (though some are 40MIPS kind)??? is fairly high compared with Atmels... if you're lucky you'll get 3-4 Atmel Atmega8 for each PIC24 you buy... market prices on big dealers like Farnell. So PIC24 is a waste of money for the 10-16MIPS range, unless you know you need it absolutely. dsPICs are fairly expensive too considering you need always 3rd party software to buy... or program by assembly!

There are plenty of e.g. books on Atmels... etc not the same for hi-end pics... not a case... they will never reach popularity of 16F84 and the like... the pipeline is so BAD on PICs! I like harward 1:1 of Atmels instead that truly give you 16MIPS for 16MHz... not 1/4 like in older Pics.

Anyway... there are so many factors... only you could know which is the best for you!

Kind regards,
Max

[Aziz]

Hi Max and all,

thank you all for supported infos. I have decided to use Atmel's AVR chips. I found yesterday tons of true free tools, applications, documentations, etc.
I also found, that bugwhiskers Universal PI Micro project is also based on ATmega and would help to go in this similar direction. I also can learn from bugwhiskers results. Also the project ClonePI could be interesting to see. On one of the german detecting site, there are also some AVR chips used (ATtiny, ATmega). Lots of usefull informations, to go on further.

My effort is addressed to the question of the comparison of PI vs. VLF based on lock-in amplifier.

I would like to make simple experiments with ATtiny2313 in the beginning time. Not totally digital PI detector but it decreases the amount of logic chips dramatically. All the rest will be realized in good old power saving analog manner. I want to realize a very simple PI project for some experiments only. Later, it could be interesting to go further with ATmega chips. They are really cheap to get: $5 - $10, depending on memory size.

For all, who wants more, I will add here the eagle schematics of my old ADSP-2181 DSP board (16-Bit DSP, 33 or 40 MIPS, 512 kB Flash Boot ROM - in system programmable, 4 MB Flash ROM for additional data storage - also in system programmable, RS232-interface, ..). The attached file is a RAR-compressed file. Remove the .zip extension.

As you can assume, I do not want making projects much more complex anymore.

Regards,
Aziz

[Max]

Hi Max and all,

thank you all for supported infos. I have decided to use Atmel's AVR chips. I found yesterday tons of true free tools, applications, documentations, etc.
I also found, that bugwhiskers Universal PI Micro project is also based on ATmega and would help to go in this similar direction. I also can learn from bugwhiskers results. Also the project ClonePI could be interesting to see. On one of the german detecting site, there are also some AVR chips used (ATtiny, ATmega). Lots of usefull informations, to go on further.

My effort is addressed to the question of the comparison of PI vs. VLF based on lock-in amplifier.

I would like to make simple experiments with ATtiny2313 in the beginning time. Not totally digital PI detector but it decreases the amount of logic chips dramatically. All the rest will be realized in good old power saving analog manner. I want to realize a very simple PI project for some experiments only. Later, it could be interesting to go further with ATmega chips. They are really cheap to get: $5 - $10, depending on memory size.

For all, who wants more, I will add here the eagle schematics of my old ADSP-2181 DSP board (16-Bit DSP, 33 or 40 MIPS, 512 kB Flash Boot ROM - in system programmable, 4 MB Flash ROM for additional data storage - also in system programmable, RS232-interface, ..). The attached file is a RAR-compressed file. Remove the .zip extension.

As you can assume, I do not want making projects much more complex anymore.

Regards,
Aziz

Hi,
good decision! I think will be very easy for you getting a PI timing section just with one AVR chip... this way you could cut away all that 4538 and the like old stuff used, with big reduction of complexity of schematic.

I think you could also jump into pulsdetektor.de and found very good projects to start with. About VLFs I think the idea is good about lock-in, you'll virtually eliminate noise impact that way, but sure is more complex project.

Anyway, let me know about your progresses.

Kind regards,
Max

[Aziz]

Hi Max,

I have to wait until the beginning of the month, before I can order some parts: I am on welfare and have a very low budget per month for the development (~50 €).
So the hardware complexity have to be dramatically reduced due to my financial situation. The software complexity does not cost me anything.

I think, I will use very likely ATtiny2313 for dedicated timing logic. Other AVR µC (ATmega8 or smaller one) might be used for multi-tone output and man-machine-interface (user-inferface). This will reduce the total complexity of the hardware dramatically (no meter/LCD display, less switches and pots if possible).

Using a very fast ADC in digital PI's makes not sense at all. The sampled signals will be interfered with noise in time-domain and they have to be filtered out anyway. The semiconductors for this purpose are very expensive and very difficult to get. So the averaging/differential integrators will work perfect.

I will go a quite different way for PI technique:

- reducing the transmit pulse power to reduce EMI and noise and also avoiding some inherent problems of FET's due to high flyback voltage. Also a problem with magnetic susceptibilty and saturation due to higher magnetic fields. My results are showing me, that there is a better way of performance instead of the brute-force-method (high coil current).

- increasing the total battery live for more operating time

- using new low noise amplifier and techniques to reduce noise

- making the hardware as easy as possible to reduce the total number of active elements

- using of external crystal clock generator with reduced jitter and timing-errors (very critical part)

- increasing the number of pulses per second (PPS) (10k..15k or more)

- decreasing the time delay after transmit power switch off to take advantage of faster dI/dt coil current decay (see Faraday's law)

- using very fast, low capacitance coils and low power, ultra fast FET's

All this stuff and more has to be reconsidered to avoid noise and drifting problems. I am sure, by increasing the signal-to-noise ratio by avoiding the brute-force method will gain more progress.



Regards,
Aziz