Hi,
Am 15.09.2014 um 22:31 schrieb Grazvydas Ignotas:
On Sun, Sep 14, 2014 at 11:56 PM, Dr. H. Nikolaus Schaller hns@goldelico.com wrote:
Am 12.09.2014 um 15:58 schrieb Grazvydas Ignotas notasas@gmail.com:
I guess audio is still to be selected, like BT/WLAN?
Plan for Audio: TWL6040 (placed on the CPU board!) since it has the best and easiest system integration with OMAP5 and has all required features (incl. built-in amplifiers). Can be replaced together with the CPU. And, it allows to have more digital signal processing (easier to shield analog signals from noise, especially GSM buzz). Potentiometer will get an ADC to digitally control attenuation. Can also be (mis)used as another game control :) And attenuation can alternatively/additionally controlled by on-screen sliders or +/- buttons giving maximum flexibility in user interface.
From my listening tests, TWL6040 sounds really bad on the EVM though,
there may be many reasons for that. Wrong firmware (where do I find the ABE_FW?) or non-optimal hardware on the EVM.
Theoretically (according to the data sheets of the Codecs) it should even be better and have lower noise than the Codec used in the OpenPandora.
but I don't have any alternatives to suggest.
Plan for BT/WLAN: WiLink6 WG7351 since the WiLink8 WG78xx modules by JorJin have less features and are bigger and unclear if they are really available.
WG7351 uses WiLink6/WL127x, which is considered legacy product by TI and they no longer support it: http://processors.wiki.ti.com/index.php/WL127x WiLink6 is not even listed on TI's product page any more: http://www.ti.com/lsds/ti/wireless_connectivity/wilink/overview.page
On pandora, with wl1251, we basically have an unmaintained driver that has many compatibility issues with various router brands, ranging from bad speeds to not working connection at all. The driver is mainlined and even N900 uses it, still nobody ever fixed numerous driver+firmware issues this chip has.
I fear the same may happen with wl127x, although the driver seems to be much further developed, the number of mainline commits for it is sharply declining.
Well, number of commits is not necessarily a good indicator. If a system is mature and most bugs have been fixed, the need for changes may decline simply because it works and no new features are demanded.
Unfortunately the modules with WiLink8 need more space.
What about the stability and maturity of the WiLink8 drivers? Sometimes I prefer well hung and mature components over the latest and greatest.
It might make sense to consider some non-TI wifi module..
If we find something compareable. We have looked at RedPine after embedded world:
http://www.redpinesignals.com/Modules/Internet_of_Things/nLink_Family/RS9113... http://www.mouser.de/Search/Refine.aspx?Keyword=redpine
and from promised feature set they are equally good.
But they are bigger, the price is twice as high, it is completely unclear which drivers exist and the modules can't be directly connected to the battery and 1.8V OMAP. So we need LDOs and glue logic around needing even more space and money.
So I fear the situation with alternative modules is even worse than with wl1251.
Something to consider instead of JorJin might be:
http://www.ti.com/lsds/ti/wireless_connectivity/wilink/products.page
BR, Nikolaus