CCS C Software and Maintenance Offers
FAQFAQ   FAQForum Help   FAQOfficial CCS Support   SearchSearch  RegisterRegister 

ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

CCS does not monitor this forum on a regular basis.

Please do not post bug reports on this forum. Send them to CCS Technical Support

I2S driver

 
Post new topic   Reply to topic    CCS Forum Index -> General CCS C Discussion
View previous topic :: View next topic  
Author Message
curt2go



Joined: 21 Nov 2003
Posts: 200

View user's profile Send private message

I2S driver
PostPosted: Thu Mar 02, 2017 4:54 pm     Reply with quote

Has anyone used I2S before to talk to an audio DAC? I am using a 24EP256GP206 chip. I know the larger chips have I2S built in but I am trying to keep the cost down. Let me know. Thanx guys.
temtronic



Joined: 01 Jul 2010
Posts: 9220
Location: Greensville,Ontario

View user's profile Send private message

PostPosted: Thu Mar 02, 2017 5:49 pm     Reply with quote

I'll play teeter-totter, plus-minus, pros vs cons,....

a) What is the 'extra' cost for a PIC with built-in I2S?

b) What is the cost (YOUR time to R&D) to cut reliable code for I2S?

I'm thinking 'a' will be a LOT cheaper AND faster. It's all in the details of course. Testing alone for your own I2S driver could take a few days depending what it has to communicate to. If this is a one-only personal project 'b' is OK, if a commercial product 'a' is the only real option. Most people don't think their time is valuable,but you should keep track of it, and even at just $50/hr....a day is $400. That will buy a LOT of PICs with I2S,remember it's only a few pennies on the PIC you chose.

Heck even the time spent here asking is costing you time and money...

Options... always think of options.

Jay
benoitstjean



Joined: 30 Oct 2007
Posts: 566
Location: Ottawa, Ontario, Canada

View user's profile Send private message

PostPosted: Thu Mar 02, 2017 6:36 pm     Reply with quote

Yes, I have and I'm using the 24EP512GP806. Given you haven't provided any details on your project, there's not much more I can say.

I haven't tried the PIC with the I2S port but using an external audio CODEC will provide probably much more flexibility. Also depending on what the ultimate end-goal is, you may or may not want to use the PIC for processing the audio.

Again, this is from my experience because my PIC does a million other things at the same time.

You can get the Texas Instruments TLV320AIC3204 but it's not that easy though. This CODEC is a fairly complex device and clocking is also complex. The CODEC is about 10$.

You can interface the PIC to the CODEC using SPI or I2C.

You also need to provide clocking to the CODEC. I use a 2.4576MHz PWM 50% duty out of the PIC for the CODEC's master clock (MCLK) along with a 128KHz PWM 50% for the CODEC's bit clock (BCLK). The result is that the CODEC outputs an 8kHz 50% duty word clock (WCLK) and the DOUT pin outputs an 8kHz 8-bit PCM bitstream. But the CODEC can go as high as 192KHz stereo.

Benoit
curt2go



Joined: 21 Nov 2003
Posts: 200

View user's profile Send private message

PostPosted: Thu Mar 02, 2017 8:51 pm     Reply with quote

I am making a little audio device. i am using 16 bit WAV files from SD card to play on small speakers. I would like fairly high quality audio. Right now I am just using a normal single ended DAC but I know I can get some better quality with and audio DAC. I was looking at using PCM5100 or something like that device. Right now I am building my audio on the DAC I am using. It works good but I know I can get better quality with an audio DAC.

Right now I just feed the DAC with 20MHz SPI. Its fast and efficient.


Last edited by curt2go on Thu Mar 02, 2017 9:00 pm; edited 1 time in total
curt2go



Joined: 21 Nov 2003
Posts: 200

View user's profile Send private message

PostPosted: Thu Mar 02, 2017 8:59 pm     Reply with quote

The difference between the 24EP256GP206 and the 24EP512xx806 is about 6 bucks. I pay right now about 6 for my current DAC but the PCM5100A is around 3. Difference of about $3. But I am looking to cut cost of the device. This is a commercial product. If it was 0.50 I wouldn't even think about it I would move to the other PIC.
benoitstjean



Joined: 30 Oct 2007
Posts: 566
Location: Ottawa, Ontario, Canada

View user's profile Send private message

PostPosted: Fri Mar 03, 2017 5:41 am     Reply with quote

Based on your comments, you seem more worried about pricing rather how such and such feature works with the MCU.

What you are trying to accomplish can be purchased as a development board from Sparkfun at the following address <https://www.sparkfun.com/products/13660> and they provide the schematics and all.

You could use that as a base and add your PIC MCU to it to do more stuff.

Good luck with your project.

Benoit
temtronic



Joined: 01 Jul 2010
Posts: 9220
Location: Greensville,Ontario

View user's profile Send private message

PostPosted: Fri Mar 03, 2017 6:16 am     Reply with quote

I was curious to see the device Ben linked in and wow.. for $50 that's a GREAT deal. Like Ben said, you could add a small, cheap PIC to do more(HMI-LCD) as ALL the hard code is done, the PCB works.
I know I can't design/make that module in an hour. Can you? I'd buy 2 of them for R&D use, see how easy it is to add a PIC for HMI and bench test for a week.

These days someone, somewhere probably has a low cost 'module' to do anything you want unlike 20-30-40 years ago when you had to wirewrap, etc., your own PCBs and hardwire a UART from a dozen 7400 series chips.
Today there's the Internet and Google......

Jay
curt2go



Joined: 21 Nov 2003
Posts: 200

View user's profile Send private message

PostPosted: Fri Mar 03, 2017 9:45 am     Reply with quote

I have already designed and commercialized the first version. I am just looking for a little better sound without changing everything. If I had the I2S driver that's really all I need. I will see what I can come up with ? Thanx for the info though.
temtronic



Joined: 01 Jul 2010
Posts: 9220
Location: Greensville,Ontario

View user's profile Send private message

PostPosted: Fri Mar 03, 2017 9:55 am     Reply with quote

For the driver, check another 'platform' and convert to CCS C. It ain't that hard...


If this is just one master --> one slave you're just banging bits. No ISRs,no feedback, just one way data ?

Jay
curt2go



Joined: 21 Nov 2003
Posts: 200

View user's profile Send private message

PostPosted: Fri Mar 03, 2017 10:10 am     Reply with quote

Yeh. That was going to be my next step. Had to try the lazy route first. Lol

Thanx guys...
Display posts from previous:   
Post new topic   Reply to topic    CCS Forum Index -> General CCS C Discussion All times are GMT - 6 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group