http://www.8051projects.net/ Learn to make simple microcontroller projects, pic, 8051, avr and arm projects. download 8051 projects, tutorials, libraries, sample codes. join the microcontroller discussion forum and ask doubts regarding electronics. the best source for 8051 over internet. en-gb This work is licensed under a Creative Commons Attribution-Noncommercial 2.5 India License.Rickey's World Disclaimer Ajay Bhargav - contact@nospam.com contact@nospam.com Mon, 01 Dec 2008 12:37:55 -0800 Mon, 01 Dec 2008 12:37:55 -0800 http://backend.userland.com/rss e107 (http://e107.org) 60 Search 8051 Microcontroller Projects AVR PIC Projects Tutorials Ebooks Libraries codes query http://www.8051projects.net/search.php http://www.8051projects.net/forum-t8692.html Hi

Im actually designing a Switch Mode Power Supply circuit.
I then would like to apply a digital control at the feedback loop using an AVR.
This is to smooth out the output signal, getting rid of the ripples and such to prove that a digital control over analog is more reliable and useful.
However, I was before using an ATmega169 on Butterfly board which now I found too complicated for a simple program like mine.
I feel like avoiding the hassle and turn to something smaller and simpler.
So do I use a Tiny AVR? If so, how do I choose which to use as there are too many of them or which one would u suggest?

My analog circuit (SMPS) basically contains:
# 3.0V input voltage from power supply
# 10kHz 6.0V pk-pk squarewave signal from signal generator
# around 5.8V output voltage (which Im gonna lower down with a potential divider before putting it into an ADC)

Really hope u could help. Thanks.


Nurul
]]> Thu, 17 Apr 2008 04:23:45 -0700 http://www.8051projects.net/forum-t8692.html http://www.8051projects.net/forum-t8692.html
why to use a development board when you can use a smaller controller and make a clean and simple stand alone board.]]> Ajay<contact@nospam.com> Thu, 17 Apr 2008 06:22:57 -0700 http://www.8051projects.net/forum-t8692.html http://www.8051projects.net/forum-t8692.html Cos before this I thot using ATmega169 is much easier as it already comes in a package with its Butterfly board.
Been stucked with this Butterfly for ages now.
But I think I'll stick with the Butterfly first and see whats gonna happen cos my deadline is very close already.

And one more thing, as on the Butterfly, we can only get access to limited pins of the AVR right?
Ive read somewhere that I could actually replace the ports available to get access to what is not.
Say now I would like to access to PORTF cos I have analog input to be fed to the internal ADC.
I read somewhere that I could actually use the JTAG ports as ADC[4:7] if JTAG is not being used.
And yes in my case, Im not using the JTAG ports.
But how do I do that? I mean how do I get access to the ADC[4:7] through the JTAG ports? Codewise?

Many thanks in advance.
]]> nuRuL<ashleybelle9802@nospam.com> Thu, 17 Apr 2008 08:12:54 -0700 http://www.8051projects.net/forum-t8692.html http://www.8051projects.net/forum-t8692.html Programming fuse bits is possible only through a serial (or parallel) programmer.If your Butterfly board has a ISP header you can connect it to a serial programmer for fuse bit programming.
Even with he JTAG enabled you still have 4 ADC channels available.Why not use them?]]> sashijoseph<sashijoseph@nospam.com> Thu, 17 Apr 2008 14:52:00 -0700 http://www.8051projects.net/forum-t8692.html http://www.8051projects.net/forum-t8692.html Plus do I actually need JTAG for my butterfly? What is it for actually?

I basically need to access PORTF of the butterfly to feed my analog output from an external circuit to be converted using the ADC.

Many thanks in advance.
]]> nuRuL<ashleybelle9802@nospam.com> Fri, 18 Apr 2008 10:02:35 -0700 http://www.8051projects.net/forum-t8692.html http://www.8051projects.net/forum-t8692.html JTAG can be used for programming the chip or for On-chip Debugging.]]> sashijoseph<sashijoseph@nospam.com> Fri, 18 Apr 2008 15:14:03 -0700 http://www.8051projects.net/forum-t8692.html http://www.8051projects.net/forum-t8692.html
well you can do this way... when compare occurs interrupt is generated and whenever interrupt occurs change state of pin.. that is all i can say right now..]]> Ajay<contact@nospam.com> Wed, 23 Apr 2008 02:12:52 -0700 http://www.8051projects.net/forum-t8692.html http://www.8051projects.net/forum-t8692.html ive one more question

say i have done my coding for PWM on timer/counter0
the output should be on OCR0 which is PB4 (according to ATmega169 pinout)
but im using my school's development board and PORTB is not connected
so my Q is how do i do the code to make PORTD to output whats on PB4?
]]> nuRuL<ashleybelle9802@nospam.com> Tue, 22 Apr 2008 22:49:42 -0700 http://www.8051projects.net/forum-t8692.html