I finished building the rear channels this week, and tested them all out. The front panel arrived from Modushop in Italy, so I mounted that today with the knobs and lcd. Yesterday I build the Dolby digital decoder board that uses a STA310 chip. On the weekend I’ll build the DAC and the microprocessor board. So hopefully within a week I’ll see if I can decode Dolby digital.
It’s been a super rewarding project so far, and most important, the LM3886 based amplifiers sound awesome.
It’s been a super rewarding project so far, and most important, the LM3886 based amplifiers sound awesome.
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That's for the 2.5V - it doesn't use much, does it? I have the 3.3V coming from a separate supply.
Oh, then it's OK.
The 2.5V current draw is next to nothing. You may add series resistor (~10 ohm) for better filtering on that line without any appreciable drop in the voltage. It's that small.
The 2.5V current draw is next to nothing. You may add series resistor (~10 ohm) for better filtering on that line without any appreciable drop in the voltage. It's that small.
For the STA310 startup code, did you do much? I have the STA310 programming guide, and they go through this exhaustive startup that covers pages and pages. Looking at the actual registers though, it seems like there are only a few critical things to do like enable the SPDIF, enable autodetection, set up the clocks, set up the PCM output style, unmute, and then run. Did you do much more?
I haven't yet. I hope to god it's version 2.0. But I don't have a working processor to talk to it yet. A few more days and the microprocessor PCB should be here. I would hope there aren't many version 1s around anymore.
I did everything as instructed.
Soft reset routine (4-5 lines)
PLL coefficients
Interrupts
Sync
I/O setup (SPDIF)
Any post processing (bass, DPL etc.)
Choose Linear PCM decoder (default).
Rest of the procedures to be done after the auto-detect interrupt has struck.
Attach your draft code, I'll tell you if you're missing anything.
Programming guide says the default PLL coefficients that are loaded at reset cover all the 48khz sampling rates (98, 196etc). Did you do that for some other reason?
It also depends on the oversampling ratio, not only sample-rate. Default = 384, I was 256, that was why.
Ok thanks. I'll take a stab at it myself at first. If I hit a wall for a long time, I'll drop you a message! Thanks.
Well, if it's V1, then you've to detect and decode the S/PDIF header (IEC61937) using the micro to find out what format it is, and then load the correct decoder. There're other tricks to identify AC3, but not DTS/PCM.
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What did you set CAN_SETUP to be? I have conflicting sections in the documentation. One section says CAN_SETUP must be 2 for SPDIF input. But in their code examples, they say it must be set to 0.
This register has controls that make sense only in case of the I2S input, not SPDIF.
If SIN_SETUP has SPDIF selected (0b1x11), CAN_SETUP is NA, set to default value (zero), that's what I've used here.
If SIN_SETUP has SPDIF selected (0b1x11), CAN_SETUP is NA, set to default value (zero), that's what I've used here.
Ok thanks.. if you read the STA310 datasheet, it says this "When the IC is configured with the S/PDIF input, reg-ister CAN_SETUP must be set to 2".. but in the programming guide, they set it to zero as well. I'll roll with zero.
Hi there. I am planning on building a DD 5.1 decoder with 6 digital out channels, hence I’m interested in the STA310 chip. @duanestorey Could I ask, where did you buy the chip from, and get the documentation? Thanks.
You might want to see duanestorey's other thread:
https://www.diyaudio.com/community/threads/lm3886-5-1-build.393554/
https://www.diyaudio.com/community/threads/lm3886-5-1-build.393554/
Thanks very much. I’ll read through, but from a quick look, tots of nice info there from yourself and OP.
Hey sorry for the late reply.
I bought mine from this vendor on Ebay - he is in Poland I think - https://www.ebay.es/itm/265335486260 I bought about 8 of them I think. I definitely had it decoding audio, so the chips are good. I need to do another iteration to improve a few things I did on that board, but it wasn't the chip's fault. It wasn't easy getting it to work, and a few other people gave me some good help. But if you want any docs or anything let me know.
I bought mine from this vendor on Ebay - he is in Poland I think - https://www.ebay.es/itm/265335486260 I bought about 8 of them I think. I definitely had it decoding audio, so the chips are good. I need to do another iteration to improve a few things I did on that board, but it wasn't the chip's fault. It wasn't easy getting it to work, and a few other people gave me some good help. But if you want any docs or anything let me know.