Month: December 2025

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/