Need help designing custom RF backpack for M5StickCPlus2 (Bruce firmware) – CC1101 + NRF24 + MicroSD

[river imp]

Hey, I’m building a custom plug-and-go RF backpack for my M5StickCPlus2 running Bruce firmware and need help figuring out the correct wiring + layout so everything works cleanly without interference.

Backpack Plan:

CC1101 (433MHz) mounted on the back

NRF24L01+PA+LNA [stacked on top of CC1101]

MicroSD SPI reader always connected [Somewhere in the backpack with a physical opening to be able to access the card]

Physical switch to select which RF module (CC1101 or NRF) is active

Shared SPI bus

Clean 3D-printed backpack enclosure

Modules:

CC1101:
https://www.amazon.com/dp/B0D2TMTV5Z?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1

NRF24L01+PA+LNA:
https://www.amazon.com/dp/B00WG9HO6Q?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1

Micro SD SPI Reader:
https://www.amazon.com/UMLIFE-Interface-Conversion-Compatible-Raspberry/dp/B0989SM146

I know how to wire each module individually, but I’m unsure how to wire all three together on the ESP32-S3 SPI bus in Bruce firmware so they don’t conflict.

Main question:

What is the correct way to wire CC1101, NRF24 (PA+LNA), and MicroSD together on one M5StickCPlus2 SPI bus under Bruce firmware so they don’t interfere with each other? Is separate CS per device enough, or should I physically power-switch the RF modules? Also any advice on minimizing RF interference when stacking them?

Appreciate any guidance from anyone who has built a multi-RF Bruce setup like this.

[craggy orchid]

Basically allin1?

[river imp]

yep

ik how to connect them all 1 by 1, but I'm struggeling figuring out how to do all 3 at the same time

[craggy orchid]

https://github.com/BruceDevices/firmware/tree/main/pcbs/StickCPlus_PCB_Pirata

[river imp]

yes but I didn't fine one with all 3 in there, and the one I found for CC1101 and NRF24 had issues with the interference between them and a shorter and less accurate range

[craggy orchid]

Damn

You need
Transistor
Resistor
Switches
If you didn't know already
https://wiki.bruce.computer/wiring-diagrams/m5stickc/sd-card-and-cc1101-nrf24/

You gotta turnoff cc1101/nrf for ir,badusb,nfc

[river imp]

I knew about the switch but I want the switch to only be for the 2 moduels while the micro SD card be in an always active state

[craggy orchid]

Can the stick even handle that much🫩

[river imp]

and how do I remove the interfearence from all 3 moduels if them being connected to the same pins is the problem?

[nova island]

@river imp before asking, did you read the Wiki? https://wiki.bruce.computer/

[craggy orchid]

Each module needs it's own switch

[river imp]

yes, but less acurate and a much shorter range for the CC and NRF

[craggy orchid]

Tbh I did made a pcb and it's plugin and plug out there's not a single switch

I just remove nrf/cc1101 and plug-in ir,nfc,badusb,etc, modules

Both nrf/cc1101 works with SD

And I can just remove the nrf/cc1101 and plug-in other modules that I need

[river imp]

ok so I would have to have it as a plug an go then, but is there a way to have it set up with a physical switch that would have CC and NRF connected to at teh same time but only 1 in use?

[craggy orchid]

Probably switch for vcc if you wanna both cc and nrf

With that you can switch between them

[river imp]

ok and what about the micro SD card, can I still have the in an always active state or do I also have to add a switch for it?