TTGO T-Beam with Dragino 915 freq

1

Hi guys.
I past last few days trying to configure ttgo t-beam to work with TTN and Dragino LG02.

After a lot of work hours, I got it working uplink.

I used this to start: https://github.com/matthijskooijman/arduino-lmic/blob/master/examples/ttn-abp/ttn-abp.ino

How title says, I’m using 915, but if I just config 915hz, my t-beam won’t communicate with dragino.
So, I made some changes in .ino.

I’m using CFG_EU_868, but setting freq to 915:

#if defined(CFG_eu868) // EU channel setup
  Serial.println("CFG_EU868");
  // Set up the channel used by the Things Network and compatible with
  // our gateway.
  // Setting up channels should happen after LMIC_setSession, as that
  // configures the minimal channel set.
  LMIC_setupChannel(0, 915525000, DR_RANGE_MAP(DR_SF12, DR_SF7),  BAND_CENTI);      // g-band
  LMIC_setupChannel(1, 923300000, DR_RANGE_MAP(DR_SF12, DR_SF7),  BAND_CENTI);      // g-band
#

And in Dragino I configured:
image

This works to uplink, but I really need downlink to made a remote action…

Debbuggng my dragino, I find downlink response from TTN:

{"txpk":{"imme":false,"tmst":1272528458,"freq":923.3,"rfch":0,"powe":20,"modu":"LORA","datr":"SF12BW500","codr":"4/5","ipol":true,"size":33,"ncrc":true,"data":"oPMYAiaKAAADQAIAcQM1AP8BATBGIrf5sRu5E7u41X/U"}}

So, Its returning SF12 in 923.3, then I configured this in my dragino like print to TX.
I tried follow some tutorials, but unique example code that I find is PAXBT that some users in this forum used.

My t-beam console:

Packet queued
58455130: EV_TXCOMPLETE (includes waiting for RX windows)

Can someone help me configure downlink? Thanks.

2

As you already noticed this will not work. The uplink frequencies are not the only differences between the regional parameters for EU and US. The downlink frequencies used are another difference.
There is another way to switch to the US915 regional parameters in LMIC and that is the way you should use to switch your node.
Your next challenge is gateway that is not lorawan compatible and should not be used on TTN. We are not providing support for those non lorawan compatible gateways on this forum.

1 Like
3

Hi, thanks for reply me.
I read about my gateway is not compatible in somewhere in this forum when I was searching about it, but I don’t understand why.

The product description is “Gateway LoraWan”, and his config screen have TTN as main function:

image

He got perfectly uplink and receive downlink from ttn, but my esp don’t received the message.

About downlink freq is different, I’ll try to change like you said. Thank you for the tip.

4

Please see the many existing threads on why single/dual channel devices cannot properly function as LoRaWAN gateways and should not be connected to TTN.

1 Like
5

Hi, i’m trying to set up a T-beam with the dragin lg-02 too, could you please send me your whole gateway settings?

6

Hopefully NOT trying on TTN - read the above thread and search many others - No Single/Dual Channel Packet Forwarders supported. Use a private LoRa-LoRa instance or your own Private LoRaWAN back end (with GW limited capabilities.) do not connect to TTN