@justin-binda the low side is the signal pin on the 3.3V side (the ESP32 / Pycom module), the high side is signal pin on the 5V side (the sensor). I think that sensor actually has two signal pins, one for trigger (MCU -> sensor) and the other for echo (sensor -> MCU) so you would need two level shifters.

@apiwize after the join worked, the TTN server will send a list of frequencies to use. The node will uses these in a random matter. Unfortunately the nanogateway can listen only to one of these three frequencies, meaning that you will miss 2 of 3 messages. That is not related to timing. The best option then is to switch to abp mode, copying over from the TTN console the values for device address, network session key and app session key. See the discussion at this thread about 10 days ago. https://forum.pycom.io/topic/2728/lopy-and-nanogateway-example-inaccurate-timing-prevent-otaa-join

Hello! I am having issue with activating using method otaa lopy with ttn gateway fot US915. whats correct code i should use I searched a lot of topics over weekend and could not find correct code. Thank you Same time using ttn node US915 with ttn gateway activation worked as shown.

@jmarcelino thanks for the clear explanation. It would be really useful if you could put this small section of code on the Getting Started section of Pycom's LoPy documentation for those who are connecting to TTN; the most popular LoRa network in Australia/New Zealand region. I will try and post something in The Things Network Australia Community page too. If you would prefer, I can raise it through GitHub, but I suspect your ability to change the Pycom documentation is much quicker! thanks again for your help Jose. Also, I really enjoyed your talk on The Things Network conference

@jmarcelino yup, thanks a lot.. i tried it outside and succeeded in getting the payloads as well..

@chuck If you're looking for a command line way you can follow the downgrade instructions: https://forum.pycom.io/topic/517/downgrading-firmware-advanced-users but using the latest version of the firmware: https://software.pycom.io/downloads/LoPy4_868-1.15.0.b1.tar.gz

@smnc As prerequisite for a ABP join you have to register an applications and in the application your device at the TTN server. See https://docs.pycom.io/gettingstarted/registration/lora/ttn.html If during device registration you select ABP, the device address and communication keys are generate by the server. This data, device address, network session key and application software key, have to be used in your script. You just copy the from you web site and put them into your script. This data will not change, unless you ask at the server to do so. TTN has a message playback protection. That might be a problem during testing. You can disable that in the device setting at the TTN server. To be able to exchange data with the TTN server, you need a node (you Fipy) and a gateway. If there is a gateway close enough you can use that one. Gateways typically accept messages from any node. LoRa uses vertical polarity, so put your antenna upright. Not doing will not harm your device, but lower the chance of successful communication.

A little update, when I power up node and nano gateway the same time everything works fine too. So the issue is when I first power up the gateway and a few seconds later the node.

@rachelsimida I gave up. I have my LoPy for 1 year and I cannot find a single working code that reads a sensor (dht22 for example) and sends it to the things network.

@roadfox Late response, but this doesn't look like a correct approach, as the join (and send) might have failed. Next time it will detect that it comes out of deepsleep and assume that it has joined, which it hasn't, so "if boot" must be replaced by something like "if successfully joined and not boot".

I'm trying to use nano-gateway with loraserver.io but I can not downstream messages just upstream. Can you share if you had the same problem?

@blackansible Try this modification in your nanogateway.py code: https://forum.pycom.io/post/8290

@seb Yes, it's in the EU, 868 Region. Using ABP, I can connect, send messages from the node (FiPy) to the gateway (LoPy), they are reported on the TTN cosole, and they arrive in the test target, but downlink messages travel only to the gateway (LoPy), are sent out by the getaeway, but almost never the node confirms reception. This may block OTAA.

Even after repeated attempts, unable to get my node working. I tried Sodaq One and lopy nano gateway which worked fine. So, I'm guessing there is a problem with my other LoPy which I'm trying to use as a node. Thanks everyone for your help.