How to send downlink from TTN to end node and gateway using frequency 433Mhz

Hi everyone, I have Dragino Lg02 as lora gateway and module ESP 32 TTGO for end node,
both is frequency 433 Mhz.
On TTN, I registered Dragino Lg02 is gateway with EU868(because I don’t see 433Mhz on TTN).
In the configuration section of dragino I configured the frequency as image below.

TTGo I use LMIC library and I have modified frequency in file lorabase.h from 868 to 433

enum { EU868_F1 = 433175000,      // g1   SF7-12
       EU868_F2 = 433375000,      // g1   SF7-12 FSK SF7/250
       EU868_F3 = 433575000,      // g1   SF7-12
       EU868_F4 = 433775000,      // g2   SF7-12
       EU868_F5 = 433975000,      // g2   SF7-12
       EU868_F6 = 434175000,      // g3   SF7-12
       EU868_J4 = 434375000,      // g2   SF7-12  used during join
       EU868_J5 = 434575000,      // g2   SF7-12   ditto
       EU868_J6 = 434775000,      // g2   SF7-12   ditto
enum { EU868_FREQ_MIN = 433050000,
       EU868_FREQ_MAX = 434900000


When I run example uplink_apb on arduino. Data uplink is working on Application TTN but downlink end node not received data from TTN (LMIC.dataLen = 0). As I see frequency downlink is 869.525. It made error, right?
here is Dragino log

TTN does not support 433MHz in Europe. Check the documentation.

And single/dual channel packet forwarders are deprecated and unsupported on here also. An LG02 is not a LoRaWAN gateway, sorry.

yes. I know TTN not support 433. but I want to try it. and I see it still receives data uplink with frequency 433Mhz. So strange :slight_smile: .
If TTN not support 433 Mhz.Do you have a solution for lorawan with frequency 433Mhz? or I have to change frequence as 868 or 915.
If I use gateway is raspberry Pi with RAK831. Can I use frequency 433Mhz with TTN or Loraserver?

You may want to consider chirpstack as an alternative to TTN

Why ?

The TTN infrastructure is provided on a free to use basis for those that are prepared to follow the TTN guidelines. It reasonable that TTN have guidelilines for thier service, as they are paying for it.

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WHY? Is it your lucky number or is it because your device can only work at 433?

If you explained yourself more, we may be able to help you find a solution.

That would simply be that the device & the gateway are configured to use 433, the device transmits, the gateway receives, the gateway relays the uplink on to TTN which probably can just cope with the rather odd frequency that was added to the meta data.

But when the downlink arrives, the gateway is unable to match the requested downlink frequency to its local frequency table and just falls over.