Hi-Fi audio preamplifier using Burr-Brown PGA2310

[philip davies]

Ok I've just changed the target IC for a PIC18F4520 in the project options to match what I currently have. I have tried the C-code that you quoted but when compiling it flags up an error in C-code. I also changed the Port A/D Enable to PORTB <4:0> configured as digital inputs on RESET . I would like to post the fc file on here but it has all been modified in FlowCode5.

[fotios]

No problem, upload it.

[philip davies]

I have just tried to upload the fcf file but the file is to big to upload. Can I e-mail it to you?

Many thanks

Phil

[fotios]

Yes, my email is in my signature

[philip davies]

Thank you

I have just sent you an e-mail containing the fc file.

Phil

[fotios]

Hi Phil
No fortune with RC5 component and P18F4xxx. I fear that there is compatibility issue of registers.
I received your email and all other in your code seems to be OK. Take a look here: http://www.matrixmultimedia.com/mmforum ... 46&t=12827

EDIT
You could try the new PIC16F1939 which is fully compatible with the RC5 component of FC and offers double program memory from this of P16F887. I have tried the RC5 component on the smaller P16F1937 with succes on actual hardware. It needs just two changes in C-code:

Code: Select all

osccon = 0x6A;
option_reg.NOT_WPUEN = 0;

[philip davies]

Hi Fotios

That's good news that there is another mcu that I can use in place of the PIC16F887 that has more memory and is compatible with the RC5. I was going to ask if you had tried it with the code I sent you but after re-reading your post I noticed it was the pic16f1937 you have. I will have to order some PIC16F1939 and give it a try.

I would like to ask did you manage to get the PIC18F4520 to run at all on actual hardware with the code I sent you? I am having difficulties with mine. Sometimes PPPv3 won't even erase the mcu

Thanks again for your help

Phil

[fotios]

Hi Phil
No, i haven't the same hardware like you to test your fcf on P18F4520 and so i use separate e-block each time to check if the micro responds to code. I have a question: in your hardware P18F4xxx prints correctly on LCD (or VFD) display? I've tried a simple text and i got errors on LCD e-block. Please look again in the other thread: http://www.matrixmultimedia.com/mmforum ... 46&t=12827 what says Ben.

[philip davies]

Hi,

My display also does not work properly with the P18F4520 but the display works fine with p18F4525. So far I have only tried the P18F4520 on a test board that I built last year for this project. I will also double check the configuration settings to make sure all is correct and then I will try the P18F4520 in my preamp as I know the preamp works fine with P16F887 and it worked with P18F4525, except for the RC5. I will let you know what I find.


EDIT

Unfortunately P18F4520 won't run on my hardware. I've tried the mcu in a test board I assembled for the project and also i've tried the mcu in the preamp. I've checked the configuration settings and tried changing various settings but so far I cannot get it to work. I think I will have to wait until I get some PIC16F1939.

Thanks

Phil

[philip davies]

Hi Fotios,

I've tried the P16F1939 and it works

The remote function works with no errors and everything runs at the correct speed. Many thanks for your time and patience, it is so very much appreciated.

Phil

[fotios]

Great news Phil
Thank you for informing me that 16F1939 works just fine. I haven't tried it so far but i will order some pieces to replace - from now on - the old good trusty 16F887 in any application.

[philip davies]

Hi Fotios,

Couldn't agree more about the P16F887. It has proven very reliable for this application. As far as the P16F1939 goes it seem to work fine in my test board but I have not installed the mcu in my preamp yet. Whilst modifying the code and trying to solve the RC5 ptoblems I decided to take apart the preamp in order to properly finish the enclosure and have it sprayed. Once the paint has properly cured I will re-assemble the enclosure and put all pcb's back in place and give it a try. Chances are the PGA2310 will work just fine with the new P16F1939 mcu.

Thanks again.

Phil

[philip davies]

Hi,

I have noticed a small glitch with the display. When power is switched on a curssor flashes on the top left corner. When the message "WELCOME!" Is shown on the display the flashing curssor is positioned after the exclamation mark. If I remove power from the mcu and display for a few seconds and re-connect them both the flashing curssor is gone. If I leave power disconnected for 10 minutes or longer the flashing curssor returns when i re-apply power.

Any ideas what could cause this problem?

Thanks

Phil

[philip davies]

Hi, I have run into a problem with the analog section of my preamp. There is no sound coming from the PGA2310. There is a signal present from the first buffer stage that connects between the input sockets and the audio input pins of the PGA2310 device but I cannot get any signal from its output pins. I have double checked all wiring on my pcb board and all seems correct. I then built the same preamp circuit on a prototyping board but still the same result.

I disconnected the data cable that connects the mcu to the data input of the PGA2310 and connected led's to the data cable instead. I wanted to see if they would flickr when connected to SDI and SCLK and if the led stays on when connected to CS when there is no data transmission. I've noticed that the led does not light up at all when connected to CS and the led does not flickr when connected to SDI or SCLK.

Any ideas what could be going on here?

Many thanks

Phil

[fotios]

Hi Phil
Which micro are you use? 16F887? 16F1937? 16F1939? There are some initialization issues regarding 16F1937-39. Please let me know.

[philip davies]

Hi Fotios,

I am currently using the PIC16F1939 for the project.

Many thanks

Phil

[philip davies]

Hi,

Problem solved
It turned out that I had a faulty ribbon connector on my ribbon cable that carries +5vdc and the serial data to the analog board. The plug had a short which sent 5vdc to the clock input of the pga2310. Removing the old plug and fitting a new one solved the problem.

Many thanks for your help.

Phil