View previous topic :: View next topic |
Author |
Message |
Guest New Guest
|
Suggestion regarding picmicro |
Posted: Wed Nov 05, 2008 12:28 pm |
|
|
Hi.
I need to develop some voice processing software.
Simple explanation:
MIC -- CHIP -- AMPLIFIER -- SPEAKER
Power supply : 3V
My job is to process all incoming voice, set some filter, send to output.
Am using picdem2 demo board so I can test just those MCU's.
Main goal is to process as much as possible data thru chip.
What chip should I choose ? |
|
|
PCM programmer
Joined: 06 Sep 2003 Posts: 21708
|
|
Posted: Wed Nov 05, 2008 4:24 pm |
|
|
Select your sample rate for audio. Let's say you choose 8 KHz.
The period is 125 us. All of your operations have to be done
in that time period. This includes the A/D conversion. Now
consider that if you run a PIC at 20 MHz, you get 5 instruction
cycles per microsecond (us). So you have 625 instruction cycles
to take a sample, process it, and write it to the (external) D/A.
Write your program, and run the MPLAB MPSIM profile menu
and see how many instruction cycles it takes to execute your code.
If it takes too many, you can reduce your code or use a PIC with
a higher oscillator speed (40 MHz). |
|
|
Guest New Guest
|
|
Posted: Thu Nov 06, 2008 2:44 am |
|
|
Quote: | If it takes too many, you can reduce your code or use a PIC with
a higher oscillator speed (40 MHz). |
I would take 40 MHz.
Maybe some 18F or better PIC24 ?
PIC24H should be OK but i dont know if i can use PICDEM 2 with it?
ww*w*.microchip.com/ParamChartSearch/chart.aspx?branchID=8186&mid=14&lang=en&pageId=75
What do you think about that choice. Do you have some other idea ? |
|
|
SherpaDoug
Joined: 07 Sep 2003 Posts: 1640 Location: Cape Cod Mass USA
|
|
Posted: Thu Nov 06, 2008 7:10 am |
|
|
This is just the sort of application a DSPic was born to do. Please consider them. _________________ The search for better is endless. Instead simply find very good and get the job done. |
|
|
Guest New Guest
|
|
Posted: Fri Nov 07, 2008 1:28 am |
|
|
Can I use dsPic with PICDEM 2 PLus and ICD debugger ? |
|
|
PCM programmer
Joined: 06 Sep 2003 Posts: 21708
|
|
Posted: Fri Nov 07, 2008 1:44 am |
|
|
Sherpa,
Have you been reading FvM's posts ? Do a search for PCD and put FvM
in as the author. |
|
|
SherpaDoug
Joined: 07 Sep 2003 Posts: 1640 Location: Cape Cod Mass USA
|
|
Posted: Fri Nov 07, 2008 6:46 am |
|
|
OK, so I guess PCD is not yet ready for prime time. Newbies should probably stay clear of it for a few months. I do intend to get it the next time I upgrade my CCS. _________________ The search for better is endless. Instead simply find very good and get the job done. |
|
|
Guest New Guest
|
|
Posted: Fri Nov 07, 2008 2:43 pm |
|
|
So suggestion would be something in PIC24H line ?
I can't find any device support list for PICDEM 2 but i guess that PIC24H should be supported ? |
|
|
PCM programmer
Joined: 06 Sep 2003 Posts: 21708
|
|
Posted: Mon Nov 10, 2008 11:19 pm |
|
|
To Sherpa:
I emailed CCS a list of all of FvM's bug reports on PCD. They emailed
me back an ID number for the bug report. So at least now they know
about the bugs. Hopefully they will fix them. |
|
|
|