CSR8645 Bluetooth 4.0 - APT-X MP3 AAC FastStream - Breakout Board
Table of Contents
Experience has shown that most / all bluetooth modules available on the market have problems of various kinds. Is it generating noise, receiving noise, have a poor coverage and/or bad audio quality.
This CSR8645 based module provides
Specification
- Input voltage range 5.5-40V (TPS7A6601), 5.0V (USB)
- alternative 6.0 60V (TPS54061) with flybuck and isolated linedriver supply
- trouble-free operation
- DSP/EQ (Kalimba DSP)
- 2Vrms output level - unbalanced via 3.5 mm jack or 1 × 3 pin headers per DRV602 linedriver
- Balanced direct DAC output
- unbalanced input (AUX line) via a 3.5mm jack socket
- AAC, MP3, APT-X, FastStream
- USB audio (optional)
- Programming via USB without dedicated USB-SPI programmer
- 5 button (optional); also available on 1 × 7 connector
- 3 LED (optional)
- 10 GPIO at 1 × 12 connector
- 1V8 <-> 3V3 levelshift for SPI/programmer
- u.FL antenna connector
- and, when using an external antenna, approx. 40m range
Hardware
AGML battery charger
Measurements
Loopback EMU 0202 (reference)
Static noise
1 kHz spectrum via BT link
1 kHz spectrum via AUX line-in
Modulation Distortion – Aux Line-In
Is the flybuck converter selected to drive this board if I for example; use this in a boombox and have noise/groundloop issues? Or is the PSRR of the TPS7A6601 enough for this application?
Correct, thats what it is for. The main problem is ground loop related when looking at a fully build amp. These BT-ICs conduct some noise when grounding/layout/wiring is bad. For this there are two solutions implemented on this board. 1st the flybuck, 2nd the DRV602 Linedriver with ground-loop-breaker. See TI AN SLOA143.
GroundLoopBreakCircuitsandTheirOperation
Until now i haven’t needed the flybuck, it always worked with the DRV602 alone. Seems like the layout isn’t that bad. 🙂
Regards, Christian
That looks fantastic and is actually the only thing that is commensurate with the chip. Is there somewhere to buy the board? Or Schematics + BOM?
Bare boards are still available.
I’d like the final schematic + BOM if available? Or could it be purchased?
If you have a board, then I gladly buy it. I can even buy two boards if available.
Best,
Alexander
Hi nice work.
Im currently working on a hobby project for the F3188.
Its a hard time to find documentation about this.
Is there any chance you could share the schematics or some documentation of the F3188?
Please head over to http://www.stromrichter.org
Hi, I picked this thread on diyaudio.com forum, and I would like to ask if this board will be up for sale? I would pretty much prefer this over questionable breakouts from alixpress…
I have some bare (unpopulated) boards available, you’ll need to solder them on your own. Regards, Christian
Did you actually try to program the this one?
How would you go about programming it?
You’ll need an SPI-USB programmer to do so, they’re available on i.e. Aliepxress (3rd party). Programming is done by the tools provided from CSR.
Was the APTX enabled by default or module needs to be reflashed by programmer?
Regards.
Yes, it works out of the box.