CC1101 + SD card support for M5stick C Plus2

[geo-tp]

Describe the bug:
When using a CC1101 module with an SD card on the M5Stick C Plus2, only one of the devices works correctly. Either the SD card or the CC1101 module works, but never both at the same time.

Steps To Reproduce:

• Connect both the SD card and the CC1101 module
• Try RF Scan/Copy, it will not work
• Remove the SD card
• Try RF Scan/Copy, now it works,but you can't save the signal on your SD card, even if you replug it

Expected behavior:
Both the SD card and the CC1101 module should work together on the same SPI bus

Actual behavior:
When one device is in use, the other stops functioning.

[eadmaster]

afaik this would require an additional free gpio pin for the Chip Select , which the M5stick lacks.

As alternative, the CC1101 can also operate without the GDO0 pin, but some features won't work this way.

[GoldenboyITA]

Can we add a phisical switch between SD card reader and C1101?!

[bmorcelli]

There are a few things to consider about the code, itself, that I'll post tomorrow to allow CC1101 and SdCard coexisting together..

But the problem is that once the SdCard is mounted, it is draining the dgo0 signals from CC1101 (for reading/scanning) preventing the stickC to read the signals, and it will only reset (for now) ir you take the SDCard physically out and reconnect it..

You could add a 3 pin button, with NC connected to the 3,3V and NO connected to GND and COM connected to SdCard Vcc pin, when btn is pressed, it connects the Vcc pin of the Sdcard reader to GND, resetting the circuit..

Tomorrow I will keep studying this issue to try to find out a way to "unmount" the SD card without mods, or proposing other connection scheme

[geo-tp]

Tomorrow I will keep studying this issue to try to find out a way to "unmount" the SD card without mods, or proposing other connection scheme

That would be great, otherwise CatHack's behavior allows for recording once (and resetting to record again), and also enables sending .sub files from SD card. This allows access to all features even if a reset is needed to be able to record/save again.

[bmorcelli]

Saving for later research..

Maybe it'll be needed to change cc1101 clk pin to avoid SDCard from backing to initial state

greiman/SdFat#351 (comment)