2022-04-26 04:34 AM
I'm trying to implement a 6- or 8-microphone arrangement, as outlined in AN5027 (p25). The recommended approach is to use an SAI with PDM interface, but I'm struggling to find a suitable MCU (and subsequently, a suitable Nucleo dev board).
I've not even seen an actual working example of this, but I'm assuming I'd configure the PDM as a mode in the SAI configuration. What I know for sure is that when I configure the SAI on my L4A6ZG, there is no option for PDM mode.
I'd welcome any advice.
Thanks!
2022-04-26 06:22 AM
Hello @falling_in2_infinity ,
We provide many examples that use an SAI with a PDM interface.
You can refer to the following examples provided under the H7 Firmware Package:
I hope this helps.
BeST Regards,
Walid
2022-04-26 06:54 AM
Thanks Walid,
That's great, thanks! So other than the H7, which other MCUs have a PDM interface? Is there a simple way to find products with a given interface? The product selector page doesn't seem to allow this level of filtering.
Thanks,
...Joe.
2022-04-26 07:37 AM
Have a look at 'G4, the L4+ (i.e. the higher-end L4 with letters in the numbering), and maybe 'L5/'U5?
We are begging ST for ages to produce a comprehensive overview of modules' versions across the various families.
JW
2022-04-27 12:35 AM
Hello @falling_in2_infinity
Take a look at the following MCUs which have a PDM interface: F2/F4/F7/H7/WB
BeST Regards,
Walid
2022-04-27 01:28 AM
Thanks JW. I'll check these out.
I join your campain to ST... it's very strange not to have such an overview. I would not even mind if more features were searchable in the product finder.
...Joe.
2022-04-27 05:20 AM
Hi @Walid ZRELLI ,
There is no SAI in 'F2 and only in some 'F4; and even in those that's the older version of SAI which has no PDM mode.
Of course PDM is just a plain bit stream and one can always use SPI/I2S which is available on every STM32, to connect one PDM source/microphone (i.e. not the "stereo" both-edges configuration) per SPI/I2S module.
JW
2022-04-28 12:40 AM
Yes, you are right @Community member there is no SAI for F2. Thanks for correcting me.