Sik radio cross compatibility

All of my Sik radios were 3DR V1 style…were at v1.6 firmware…got another newer set…came with 1.9 firmware…tried getting the new set to interoperate with the old, no luck…so upgraded firmware on all radios to 2.0…
all the old sets talk to one another…the new set talks to each other, but the new and the old do not talk to one another…
same firmware…exact same settings (as shown in Mission Planner) for every radio…
any ideas on why old v1 and newer V2 style radios running the same 2.0 firmware, and settings, wont talk to one another???

Have you seen this? He seems to have had the same problem

v1.9 (and earlier) isn’t compatible with v2.0, but radios on v2.0 should all talk to each other.
I know you’ve said all settings the same, so I’m hesitant to ask the obvious: but baudrate, RTS/CTS, ECC, channels, Net ID, freq range the same on all?

all that are shown in the MP display box are exactly the same for all modules

I programmed all radios using MP while directly connected via USB or FTDI…set all params to default…all read back the same…btu the V1s only talk to one another (4 radios)…and the V2s only talk to one another…again, all params exactly the same…all 2.0 firmware

For better or worse I haven’t been able to replicate this.
What I’ve done is, using MissionPlanner:

  1. updated a v1 3DR ground radio (probably 6 or 7 years old) and a v2 3DR radio to latest (SiK v2.0 for hm-trp)
  2. reset both to defaults.
  3. Connect.

These radios:

These settings:

which resulted in successful connection:

I’ve also tested with a generic (non 3DR) SiK ground radio of an unknown hardware version.
I know that doesn’t solve the problem for you. Sorry.

I have a bunch of SiK telemetry modules laying around:

  • 2x original 3DR V1 air modules
  • 2x 3DR V2 clones of unknown source (looking similar to those: Productlink to Banggood)
  • 2x Drotek modules (productlink to Drotek)

All of them share the same firmware (SiK 1.9 on HM-TRP) and settings.


  • The 2 Drotek modules and the Original V1 modules can link (green LED solid) in every combination.
  • One of the 3DR V2 clones exclusively links with the second clone, whereas the second clone can also link with the 2 Drotek modules, but not with the V1 modules.

I cannot figure out what the reason for this behaviour is. I uploaded the firmware to each of them myself and double checked all the settings. I don’t think it is a software issue. I also tested this with the latest firmware (RFD SiK V2.0 on HM-TRP) and got the same results.

Since they all share the same Si1000 MCU with the same firmware on it, they should all be compatible to each other, right? Are there any other components (e.g. antenna) that can lead to such problems?

Unfortunately i cannot upload those picture directly.

  • Picture 1 (Link to OneDrive) shows a V1-module on COM82 and a V2 clone on COM9 - no link
  • Picture 2 (Link to OneDrive) shows a Drotek-module on COM78 and the same V2 clone on COM9 - link

edit: I just saw on picture 1, that the “Tx power” parameter was varying, but I also tested with both on 20dBm

A LOT of the 3dr clones use the wrong analog filter chip…they work(poorly) with one another, but not the correct units that have the correct filtering

By “analog filter chip” you mean the passive electronic components around the S1000 µC?

Also I got myself a Holybro V3 telemetry kit (productlink to Holybro). Those modules work fine with all other modules except with one of the 3DR V1 modules. They link just for short time periods. Any idea to that?

A radio witrh V1.9 will not work with a radio on V2.0 if that is relevant.

I do have all my radios flashed on firmware version 1.9, you uploaded here.
Thank you by the way. :smiley:

I did test most of the radio combinations with firmware version V2.0 as well, but got the same results.