CSR8645 Bluetooth 4.0 AAC APT-X Module / Baseboard

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orto

orto

Member
Joined 2006
funkstrong.com
I can't seem to connect to my csr8645 chips. I'm running a FT232RL breakout board with no luck. Using this guide - https://github.com/lorf/csr-spi-ftdi

The instructions I'm using say this:

"Some chips (like CSR8645) share SPI pins with PCM function. For such chips to be accessible via SPI, SPI_PCM# pin should be pulled up to I/O voltage supply through a 10K resistor."

Can anybody explain what "pulled up to I/O voltage supply" means? Does this just mean I need to use a 10k resistor to give this pin 3.3 volts?


Here are some pictures of my current mess:

O5tbSll.jpg

hrOCKLt.jpg
 
B

Buriedcode

Member
Joined 2011
I used the '1V8' output of the module to power the IO of the FT232, and as the voltage for the pull up on SPI_PCM line. I have seen others use 3.3V for IO, which should be fine providing you have series resistors.

That particular module you have has built in power-enable (delays the pwr_e line high by about 10ms).

Remember to only use PS_tool, and never write to the module using the headset configuration utility :)
 
W

wchpikus

Member
Joined 2016
I propose make backup (dump) psk keys to local using PSTool before You change something.
Buriedcode has right, to not write psk keys uning headset configuration utility..

I got one more question, anybody has Sink configure tool??
I got 8670, but is the same problem, data out from PCM is visible, no clock and WS on PCM lines...
 
B

Buriedcode

Member
Joined 2011
yuriy m said:
Guys say it's better to play a USB DAC.
pcm2704 or csr8645 ?
Click to expand...

Depends on what you want. The CSR8645 is a bluetooth module that *can* use (depends on the ROM) the Apt-X codec which is excellent quality. I've seen ads claiming 'CD-quality' but that is entirely subjective. The worst is those that confuse standard Apt-X to 'lossless Apt-X'. Bluetooth only uses either stock Apt-X or the low latency version, both are lossy.

Also, being a wireless system, whilst it can mask errors, it cannot eliminate them so there will be errors, and drop-outs at the limits of range/interference. With that said, I'm pleasantly surprised by these devices, plugged into a reasonable Bose system, at high volume, with my phone 8 metres away, I didn't hear any hiss or artifacts - so its fine for just listening.

USB audio has its own issues, that may or may not be a problem, depending on what you want. If you want 'the absolute best quality' and have very expensive gear (which means you can afford other expensive gear, and don't want to have a weak link in the chain' then perhaps something other than bluetooth or USB audio.

Again, the USB DAC's I've heard, including the low end single chip solutions (C_media) sound excellent to me. They are isynchronous, with some high end being asynchronous, so the former will always have some form of jitter. Again though, its subjective, just because it isn't 'perfect' doesn't mean to say you can hear it.

I haven't tried its USB to audio capability yet, it bluescreened my PC when I plugged it in, but that was most likely me screwing around with the pskeys :)

Note the PCM1704 isn't a USB DAC, just a high-end DAC. So the quality will be determined by the USB device chip, output buffers, layout etc.. You can't compare that with the CSR8645 - they do different things.
 
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