determining microcontroller speed & memory size - diyAudio
Go Back   Home > Forums > General Interest > Everything Else

Everything Else Anything related to audio / video / electronics etc) BUT remember- we have many new forums where your thread may now fit! .... Parts, Equipment & Tools, Construction Tips, Software Tools......

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 3rd November 2006, 11:05 AM   #1
squadra is offline squadra  Netherlands
diyAudio Member
 
squadra's Avatar
 
Join Date: Dec 2003
Location: only in your mind.
Default determining microcontroller speed & memory size

I am building a remote controlled pre amp.
Functionality is limited to selecting one of the four inputs and selecting the required attenuation.
Selecting the correct input is done via relais, and volume selection via relais (TVC) or PGA2311 (will test both).
The relais will be controlled via serial/parallel converters.

Because of it's low price I have ordered the AVR ISP and downloaded the AVR studio software; it will be an AVR microcontroller
The AVR attiny 26 is cheap, which makes it a good candidate
It has been very long since I have worked with microcontrollers and assembly and I am wondering how to determine the clock speed for the RC5 receiver.
The AVR has an internal clock of 1MHz, this is probably fast enough for decoding RC5?

Memory size is not important, I only need a few bytes for the actual channel & volume settings.

Also I have no idea what flash size is necessary, are there guidelines for this?
__________________
I'm ready to prove everything I have said,
for I can find good witnesses.
  Reply With Quote
Old 3rd November 2006, 12:31 PM   #2
Wynand is offline Wynand  South Africa
diyAudio Member
 
Wynand's Avatar
 
Join Date: Mar 2005
Location: Cape Town
Did you get the low voltage version ATTiny26 or ATTiny26L
  Reply With Quote
Old 3rd November 2006, 12:39 PM   #3
Wynand is offline Wynand  South Africa
diyAudio Member
 
Wynand's Avatar
 
Join Date: Mar 2005
Location: Cape Town
It doesn't really matter, but why not use a crytal, we made a remote control for a pc, using a atmega32 and a 6Mhz crystal.

It adds frexibility to the design (and accuracy).
You can alway use the prescaler to get a slower freq.
  Reply With Quote
Old 3rd November 2006, 12:46 PM   #4
squadra is offline squadra  Netherlands
diyAudio Member
 
squadra's Avatar
 
Join Date: Dec 2003
Location: only in your mind.
Quote:
Originally posted by Wynand
Did you get the low voltage version ATTiny26 or ATTiny26L
It is the ATTiny26, max. 16MHz version.

On a webpage I found the speed of RC5 is only about 560Hz (1.8ms per bit).
I thought it was 36kHz, but that is just the carrier.
__________________
I'm ready to prove everything I have said,
for I can find good witnesses.
  Reply With Quote
Old 2nd November 2013, 06:52 PM   #5
Pyramid is offline Pyramid  United States
diyAudio Member
 
Pyramid's Avatar
 
Join Date: May 2006
Location: Behind the Cheddar Curtain
squadra- Regarding your question about xtal selection: If you are going to use the serial port for input, then you might want to pick a xtal that will give you an exact (or close) baud rate of 560. If you are going to decode by looking at an edge to start and use software delays to sample (or oversample for best noise rejection) the input stream, then just about any xtal will give the the needed resolution at the RC5 baud rate. When considering xtal selection, I always consider all peripherals attached to the micro, timing and delay requirements, tone generation accuracy and resolution, number of interupts and service speed or anything else that might create a timing issue. Rarely can you find a xtal that will meet all of the requirements exactly, but compromises can be made and a choice can be determined that should meet all your criteria.

Flash size is less of an issue today than it was years ago when devices were very limited to 2K (8749) or 4K (8751). Choice of programming language may make a difference, in my experience, assembly language requires far less space than C. You will want to leave a comfortable (apply your definition here) buffer of extra code space in case you want to make changes or add capabilities in the future. I do not know of any formula or equation that would apply to flash size. Usually, more is better, balanced with cost and pin count needed to get it.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
help with Brazilian microcontroller Danilo Almeida Digital Source 1 11th February 2009 02:23 PM
Microcontroller Help imix500 Parts 8 3rd September 2008 03:49 AM
help with microcontroller sss Everything Else 2 31st July 2008 05:30 PM
microcontroller programming traf Digital Source 7 12th September 2007 01:49 PM
No microcontroller for PGA2310? louischia Chip Amps 12 4th March 2007 07:12 PM


New To Site? Need Help?

All times are GMT. The time now is 08:03 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2