DIY WiSA Home Theater system

[Glider95]

Hello,

Here is some update.
I have received my Logic Analyzer - Cheap one that connect to USB and work with Salae software.

I have managed to capture some I2S Signal from the RX board as follow:
Channel 0 is the Clock
Channel 1 is LRCLK
Channel 2 is Data 0
Channel 3 is Data 1 (which seems to be the same as Data 0)

But I am not sure of the settings:

However, I have been able to confirm that when changing the speaker assignment to each different position of a 5.1.2 setup and sending a "chime" via the application -> a signal is visible on the analyzer.
Would it confirm that all data are on one line ?


EDIT:

I was able to confirm the theory above:
I also ordered a small I2S DAC MAX98357 Mono D-Amp, after a piggy-back on the I2S signal and connect to a cheap speaker -> IT WORKS !
All the 8 channel work independently without issue and I can assign the speaker to each channel as I wish.
Next step: To figure out the function of the 18-ish remaining pins, even though most of them are not mandatory to make something out of this receiver... (Except if there is some kind of boot sequence from the DSP to Receiver)

(Sorry a bit messy)



Cheers,

 

[Glider95]

Hello,

Some updates:
I found the UART Communication pins and could look at some logging from the RX:

There is details on the:

• WiFi canal
• The volumne in HEX format
• the Mute 1/0
• some details on the board origin (RW-34)

I have progress on understanding the pin-out (Refer to previous pictures for Pin 1 and 24):
Green are confirmed pins, white is expected and ? is unknown.
I am not sure why, I2C connection does not seems to work.

I am not sure on the next steps, do I need to know everything about the board or should I continue on integrating to speakers?

I was looking at I2S Digital amplifier and there is not that many on the market:
- MAX98357A - Super cheap but can only output 3W.
- A range of Texas Instrument (TAS58XX series) which seems to be a nice choice, some of them even include a DSP but it seems that TI tools are required for this:
- This project would almost fit perfectly my need and is almost all done: https://github.com/tonyp7/TAS5806M-Audio-Amplifier ->
- Another one on TAS5825M - https://github.com/Darmur/bassowl-hat
- And other small ones...

 

[Glider95]

Hello,

Following my post in the I2S Amp thread:

I have received the draft design, from a hired free-lance, to use TAS5828M and I would like to get your opinion before sending it for manufacturing:

Would anyone would be able to cross check on the Smart Amp / Class-D amplifier before I place a 100$ order for manufacturing ?
Due to availability at JLPCB, I had to switch C2 and C3.

All the files are available : https://github.com/Glider95/TAS5828M--Audio-amplifier

BOM:

​

Any comment would be of great help !

 

[MCH]

Hey @Glider95
Glad to see your project alive and kicking
I am not knowledgeable enough to give you any advice on the PCB. It calls my attention to see all those corners but I know it is a controversial subject. Does your designer know it is a switching amplifier? Also, the amp chip output traces (the two in the centre of the chip), seem a bit unnecessary thin and long. How many watts can this output? Are you printing it on 2oz copper?
The evaluation board of the amp is very well documented with detailed schematics, BOM and PCB design, have you seen it? (screenshot below)

TAS5828MEVM Evaluation board | TI.com

View the TI TAS5828MEVM Evaluation board description, features, development resources and supporting documentation and start designing.

www.ti.com

There is a sub Reddit called r/PrintedCircuitBoard that is all about people posting pcb designs and schematics asking for advices and review. I recommend you to post there, ASR population is all about buying, not too much real DIY going on here -except for speakers maybe
Good luck!

Edit: I read in another thread that it outputs 100W. If you plan to drive it that hard, I suggest you to check with a trace calculator how hot those traces can get and modify accordingly if needed

 

[Glider95]

Hey @Glider95
Glad to see your project alive and kicking
I am not knowledgeable enough to give you any advice on the PCB. It calls my attention to see all those corners but I know it is a controversial subject. Does your designer know it is a switching amplifier? Also, the amp chip output traces (the two in the centre of the chip), seem a bit unnecessary thin and long. How many watts can this output? Are you printing it on 2oz copper?
The evaluation board of the amp is very well documented with detailed schematics, BOM and PCB design, have you seen it? (screenshot below)

TAS5828MEVM Evaluation board | TI.com

View the TI TAS5828MEVM Evaluation board description, features, development resources and supporting documentation and start designing.

www.ti.com

There is a sub Reddit called r/PrintedCircuitBoard that is all about people posting pcb designs and schematics asking for advices and review. I recommend you to post there, ASR population is all about buying, not too much real DIY going on here -except for speakers maybe
Good luck!
View attachment 410519

Edit: I read in another thread that it outputs 100W. If you plan to drive it that hard, I suggest you to check with a trace calculator how hot those traces can get and modify accordingly if needed

Thank you for your feedback !

If you are referring to this strip:

I believe it used for cooling of the chip itself. I forgot where I read that but I remember something around that line.

As you mentioned in your edit, the chip is capable of 100W mono output. Upon your feedback and also received from the subreddit comments (posted as you advised ) , I believe I might have to oversize a bit the traces and input connector to handle up to 24V input power.
Personally, I don't think I will go up high in output power as the most consuming part of my speakers would be 2 ways bookshelf ( I am looking at this base build : Erikdidit - bookshelf - Video) for around 50W.

 

[MCH]

Thank you for your feedback !

If you are referring to this strip:
View attachment 410778

I believe it used for cooling of the chip itself. I forgot where I read that but I remember something around that line.

As you mentioned in your edit, the chip is capable of 100W mono output. Upon your feedback and also received from the subreddit comments (posted as you advised ) , I believe I might have to oversize a bit the traces and input connector to handle up to 24V input power.
Personally, I don't think I will go up high in output power as the most consuming part of my speakers would be 2 ways bookshelf ( I am looking at this base build : Erikdidit - bookshelf - Video) for around 50W.

No, i refer to these ones below:

these traces carry the amplified signal, that if you push the amp and/or you have a difficult load, they can carry significant current. The traces as you have them are the thickness of a pin (0.2 mm maybe?) and relatively long. If you are using regular 1oz copper, i suggest to pay attention to it, and if too late to change and in doubt, consider 2oz copper, that is a game changer. Look how TI solves that:

The traces start thin, as it needs to be to fit the pads, but as early as possible they make them as thick as possible.
Probably i am exaggerating and there is no problem, but rememeber the motto: the copper is for free.

Regarding the thermal pad that you mention, what you have looks fine enough. If it was me and specially if you plan to put a lot of electronics in a small closed enclosure, i think that out of precaution i would leave provision for a small heat sink, that is, a couple of mounting holes to each side of the chip. In your case it should be easy as the thermal pad is on the bottom. (edit: hmm, i see your rendering that suggest the pad is on the bottom, but are you sure about it? the datasheet suggests it is on the top, but maybe there are different versions of the chip? anyways, if it is on the top, i would definitely redesign the board to add a heat sink, see the next post). Again, probably not necessary, but it is for free and the is no way back if you dont have them.

Cool that you posted it in reddit, will go there see what people suggest

 

[MCH]

I oversaw it before, but TI eval board indeed uses a heat sink, and not small precisely:

look at the mounting holes for it at the sides of the chip i like i was suggesting:

remember this is an evaluation board, made to be capable to bring the amp to its limit, but still, imo, better be conservative than to regret, specially if you have the space. The BOM of the eval board should detail what heatsink they use exactly to give you an idea (i did not check).