DJI RC-N1 dmesg output

Plug the remote control USBC power connector to your computer and press the power button, after some seconds you should see:

[14386.624454] usb 3-5: new full-speed USB device number 9 using xhci_hcd
[14386.809106] usb 3-5: New USB device found, idVendor=2ca3, idProduct=0040, bcdDevice=ff.ff
[14386.809112] usb 3-5: New USB device strings: Mfr=0, Product=0, SerialNumber=0
[14391.761634] usb 3-5: USB disconnect, device number 9
[14395.694447] usb 3-5: new high-speed USB device number 10 using xhci_hcd
[14396.083395] usb 3-5: New USB device found, idVendor=2ca3, idProduct=1020, bcdDevice= 4.04
[14396.083402] usb 3-5: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[14396.083404] usb 3-5: Product: C5
[14396.083406] usb 3-5: Manufacturer: DJI
[14396.083407] usb 3-5: SerialNumber: 1WPBJ7V006048C
[14396.119995] cdc_acm 3-5:1.2: ttyACM0: USB ACM device
[14396.120310] cdc_acm 3-5:1.4: ttyACM1: USB ACM device
[14396.120325] usbcore: registered new interface driver cdc_acm
[14396.120327] cdc_acm: USB Abstract Control Model driver for USB modems and ISDN adapters

Then I decided to get the SPI Flash from the other DJI RC-N1 and solder in this same board and it changed the ID to:

[23040.889495] usb 3-5: New USB device strings: Mfr=0, Product=0, SerialNumber=0
[23045.655386] usb 3-5: USB disconnect, device number 13
[23049.598124] usb 3-5: new high-speed USB device number 14 using xhci_hcd
[23049.986619] usb 3-5: New USB device found, idVendor=2ca3, idProduct=1020, bcdDevice= 4.04
[23049.986623] usb 3-5: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[23049.986624] usb 3-5: Product: C5
[23049.986625] usb 3-5: Manufacturer: DJI
[23049.986626] usb 3-5: SerialNumber: 6NYXKBR02603AN
[23049.992075] cdc_acm 3-5:1.2: ttyACM0: USB ACM device
[23049.992550] cdc_acm 3-5:1.4: ttyACM1: USB ACM device

Pager POCSAG and FLEX links

I already played with Pager before (if you search for POCSAG or Pager here will find some posts), but it is a rabbit hole, every time you search for it will discover many useful things. So I decided to list some useful links here:

Pager for HAM guys: https://www.qsl.net/kb9mwr/projects/pager/plan.html

Details about Motorola Advisor board and crystal: https://goughlui.com/2016/01/15/tech-flashback-motorola-advisor-pocsag-5121200bps-pager/

MotoLoRa, this guy used the Pager Advisor as a screen to a LoRa communication: https://hackaday.io/project/183267-motolora-advisor/details

FLEX protocol implementation: https://github.com/dl1com/flex

Another page with FLEX protocol info and implementation: https://www.discriminator.nl/pdw/index-en.html

Phillip Johnstop from Emdedded Artistry post about debugging FLEX: https://embeddedartistry.com/blog/2019/12/02/a-case-study-on-finding-fixing-and-testing-a-firmware-bug-without-hardware/

Yocto tips

Search for a package on yocto recipes:

$ oe-pkgdata-util list-pkgs | grep packagename

Another way to search for a package:

$ bitbake-layers show-recipes | grep packagename

List of files that a package will provide:

$ oe-pkgdata-util list-pkg-files packagename

Search for a text in the package receipt:

$ bitbake -e packagename | grep -i texttosearch

Clear the package compiled previous

$ bitbake -c cleanall packagename

How to compile verbose a package using yocto:

$ bitbake packagename -c compile -f -v

Akaso Brave 7LE reverse engineering

While searching for info about reserve engineering this device I found some useful information.

This camera uses the iCatch V39 processor.

If you remove the battery, press and hold the shutter button and plug the USB cable it will enter in debug mode. On Linux you will see:

[ 3795.696924] usb 1-1: new high-speed USB device number 5 using xhci_hcd
[ 3795.820785] usb 1-1: config 1 has an invalid interface number: 5 but max is 2
[ 3795.820790] usb 1-1: config 1 has no interface number 2
[ 3795.821237] usb 1-1: New USB device found, idVendor=2aad, idProduct=6370, bcdDevice= 0.00
[ 3795.821240] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 3795.821242] usb 1-1: Product: General USB Device
[ 3795.821243] usb 1-1: Manufacturer: General Ltd

Fonte: https://github.com/Linouth/iCatch-V50-Playground