AVR acoustic spectrum analyzer

Step 6 Jumper and other options

Components used in filter must be exactly as on schematic, and better if they will be new, especially capacitors. Two 470ohm resistors that makes the 2.5V reference voltage must be similar as possible. Some of avr’s (especially the new ones produced after 2008) are not susceptible to overclocking very good… program overclocks BADLY the ADC while measuring the high band signal. If you can’t see anything on the right side of display, this means that your ADC is not working. Solder the LOW PRESC jumper to reduce frequency of ADC, it will apply prescaler 4 instead of 2. If you are using VFD, solder the VFD jumper to send special brightness regulation commands instead of controlling PWM output. This can not be used together because the LCD wrongly recognize this command and its start to be unusable.

I am the author of hardware and part of the software, author of software is Hunterhouse user.

Source codes are included

All needed files are in the attachment. I know my english it's not too good, so ask if something is unclear.

Good luck!

Oh, and if you want fast response to your question, please ask in comments on my site or contact me.

ATTENTION ATTACHMENT WAS UPDATED. Previous contained a little bug in programms.

Comments

[Mikkel324]

Hello.

Excellent project, I have been looking for something like this for a while.

I will try putting it together later today, I have a lot of Noritake VFDs that I need to put to use.

There's just one thing I'm wondering about. I notice it uses the display in 4-bit mode. I have had some trouble with Noritake VFDs in 4 bit mode before, are there enough free IOs to make it use the display in 8 bit mode?


A.M.

[manekinen]

Hi! There is no even one free pin left. I have problems with this VFD too, but i don't think that is 4bit bus mode fault. My VFD has problem with changing the definiable chars while running, i can change them on start with no problems. When i try to change them while working, display just don't release busy flag and program hungs up, as seen on my movie, its reseted by watchdog - and it happens very often. I have tried a lot of tricks to avoid this but vfd keeps hunging up :(

And what are yours problems with VFD's? Can you test this analyzer on your VFD's and tell me if you have the same problems as me?

[Mikkel324]

Hello.

I have had many strange problems with using the Noritake VFDs in 4 bit mode, also that it won't go out of busy, leading programs waiting for the VFD to crash and other strange stuff. I have had this problem with both new and very old HD44780-compatible Noritake VFDs. The problems have always gone away when I have switched to 8 bit mode. This is very frustrating, but I don't know about any other solutions.

Are PB0-5 used for buttons? Maybe you could multiplex the buttons onto the VFD data bus.

Anders M.

[manekinen]

You can throw away buttons and throw away two pins for selecting VFD and low prescaler - and you got 7 free pins. Maybe if i found some free time i will try to do this on 8bit mode and do more tests of these noritake vfd, which is, not 100% HD44780 compatible :( I don't know maybe there is some extra commands that pdf don't describes? I tried to switch off and on and do another init before sending definiable chars, i even edited compiler lcd library to make a little longer timings... same bug.

[amishx64]

@ Everyone

If you guys are having trouble getting the right project file downloaded 
all you guys need to do is change the file extension on file you downloaded from .tmp to .rar

so instead of FP3YICPG3KY0NSJ.tmp
it should say FP3YICPG3KY0NSJ.rar

If you can’t see the file extension, go to ‘Tools’ –> ‘Folder options’ –> UNcheck “hide file extensions for known file types”

Hope this helps.

amishx64