# OTAA with LMIC and arduino+dragino\_shield doesn't work **URL:** \ **Category:** End Devices (Nodes)\ **Created:** [January 18, 2017, 10:47am UTC](https://www.thethingsnetwork.org/forum/t/otaa-with-lmic-and-arduino-dragino-shield-doesnt-work/4905 "2017-01-18T10:47:29Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![salvatore\_forte](https://www.thethingsnetwork.org/forum/letter_avatar_proxy/v4/letter/s/b4bc9f/32.png) [@salvatore\_forte](https://www.thethingsnetwork.org/forum/u/salvatore_forte)\ **Post date:** [January 18, 2017, 10:47am UTC](https://www.thethingsnetwork.org/forum/t/otaa-with-lmic-and-arduino-dragino-shield-doesnt-work/4905/1 "2017-01-18T10:47:29Z")
Hi all, I am trying to activate my arduino+dragino\_shield v1.3 with OTAA procedure, but it doesn’t work as it should be. Just to make things crystal clear, I uploaded the basic “ttn-otaa” example provided by the LMIC library. I payed attention in setting the DevEUI and AppEUI in LSB, whereas the AppKey in MSB, as advised in the code itself. The packets are sent to a close by Kerlink Wirnet Station. The same node registered with ABP works just fine, and I can see packets back and forth the TTN back-end server with no problem at all. After sending a join request, actually, I get the DevAddr and authentication keys (NwkSKey, AppSKey) from the server since I can see them in the TTN console, but I have feeling like my node can’t successfully use them to start sending my “Hello World” payload. In fact, after few minutes a new join request is sent and I get new keys without going any further in the data exchange process. To give you the all picture, I post few screenshots of the console status at this time, as well as the response of the Arduino’s serial monitor: **End Node keeps sending join requests** ![](https://www.thethingsnetwork.org/forum/uploads/default/original/2X/c/c8f7944a28fcf37ca71a098113d47f8f7cf1e510.jpg) **End-node apparently activated (TTN shows all keys)** ![](https://www.thethingsnetwork.org/forum/uploads/default/original/2X/3/39eb0c6148d46b9991177e5f74ce86ab0e08c8a3.jpg) **Arduino Serial Monitor (stuck in join procedure)** ![](https://www.thethingsnetwork.org/forum/uploads/default/original/2X/2/2df92e58ed96a7e8676a2f85e8f880536900ac62.jpg) I hope that someone that has experienced the same problem can give me a piece of advice about how to fix it! Many Thanks! Salvatore ---
**Author:** ![jdelaet](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/jdelaet/32/8164_2.png) [@jdelaet](https://www.thethingsnetwork.org/forum/u/jdelaet)\ **Post date:** [January 18, 2017, 8:33pm UTC](https://www.thethingsnetwork.org/forum/t/otaa-with-lmic-and-arduino-dragino-shield-doesnt-work/4905/2 "2017-01-18T20:33:37Z")
OTAA join might take up to 7 minutes with the libarary and sketches as found on the net. There is a fix that you can add at the end of the statements where you init the node. ``` // got this fix from forum: https://www.thethingsnetwork.org/forum/t/over-the-air-activation-otaa-with-lmic/1921/36 LMIC_setClockError(MAX_CLOCK_ERROR * 1 / 100); ``` ---
**Author:** ![salvatore\_forte](https://www.thethingsnetwork.org/forum/letter_avatar_proxy/v4/letter/s/b4bc9f/32.png) [@salvatore\_forte](https://www.thethingsnetwork.org/forum/u/salvatore_forte)\ **Post date:** [January 19, 2017, 8:42am UTC](https://www.thethingsnetwork.org/forum/t/otaa-with-lmic-and-arduino-dragino-shield-doesnt-work/4905/3 "2017-01-19T08:42:51Z")
Hi jdelaet, thanks for the answer. I fixed the sketch by adding that line of code, however I am still struggling to have it working. In fact, I can establish a connection with server only once at the startup of both the arduino end-node and gateway. As soon as I remove power to the arduino board (or alternatively push the arduino’s reset button) I can’t activate my device any longer. I guess that at the end of a session I should be able to normally open a new one and get new keys for the end-node. Look forward to get useful tips to overcome this issue! Regards, Salvatore ---
**Author:** ![jdelaet](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/jdelaet/32/8164_2.png) [@jdelaet](https://www.thethingsnetwork.org/forum/u/jdelaet)\ **Post date:** [January 19, 2017, 11:36am UTC](https://www.thethingsnetwork.org/forum/t/otaa-with-lmic-and-arduino-dragino-shield-doesnt-work/4905/4 "2017-01-19T11:36:47Z")
I am not sure what you mean with “session”. After joining, are you able to transmit messages? Let’s say every 5 minutes? And where does it stop when you reset or repower? Are you able to share you sketch with us? ---
**Author:** ![salvatore\_forte](https://www.thethingsnetwork.org/forum/letter_avatar_proxy/v4/letter/s/b4bc9f/32.png) [@salvatore\_forte](https://www.thethingsnetwork.org/forum/u/salvatore_forte)\ **Post date:** [January 19, 2017, 11:54am UTC](https://www.thethingsnetwork.org/forum/t/otaa-with-lmic-and-arduino-dragino-shield-doesnt-work/4905/5 "2017-01-19T11:54:32Z")
Hi jdelaet, I try to answer to each point you made: - for “session” I mean a properly established connection, which follows a join request coming from the end-node. - after a join accepted, I can send packets to server, and I see payloads on the device section of TTN console. - As soon as I unplug, and then plug USB power cable to the arduino board back again, I can’t activate my device thorugh OTAA any longer, unless I reboot the gateway. ABP works just fine instead (even when I unplug/plug power to the Arduino) and a reboot of the gateway is not needed. - the sketch is the otaa-ttn.ino example provided with library (I fixed the bug with the correction you told me - LMIC\_setClockError(MAX\_CLOCK\_ERROR \* 1 / 100) ). Thanks a lot for the help, I look forward for your reply! ---
**Author:** ![jdelaet](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/jdelaet/32/8164_2.png) [@jdelaet](https://www.thethingsnetwork.org/forum/u/jdelaet)\ **Post date:** [January 19, 2017, 12:22pm UTC](https://www.thethingsnetwork.org/forum/t/otaa-with-lmic-and-arduino-dragino-shield-doesnt-work/4905/6 "2017-01-19T12:22:38Z")
Is there any output on serial monitor when you reset or repower? On the other hand I would start to look at logging in your gateway. There is not that I can help you there. I noticed that you opened a new topic for this already. ---
**Author:** ![salvatore\_forte](https://www.thethingsnetwork.org/forum/letter_avatar_proxy/v4/letter/s/b4bc9f/32.png) [@salvatore\_forte](https://www.thethingsnetwork.org/forum/u/salvatore_forte)\ **Post date:** [January 19, 2017, 1:25pm UTC](https://www.thethingsnetwork.org/forum/t/otaa-with-lmic-and-arduino-dragino-shield-doesnt-work/4905/7 "2017-01-19T13:25:35Z")
Here you can find the output from arduino serial monitor: as you can see it keeps sending a join request increasing the spreading factor at each new tentative. However, it goes on forever, until I get the event join failed. I have tried many times, the only way to make it works is rebooting the gateway. Debug through serial monitor ![](https://www.thethingsnetwork.org/forum/uploads/default/original/2X/a/a2c5ca2304eb3c92837212f697365526c2150924.jpg) TTN console ![](https://www.thethingsnetwork.org/forum/uploads/default/original/2X/f/f3c39d10e90115197f4b68c5a92bf7f3149c0918.jpg) ---
**Author:** ![3DPrinterDoctor](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/3dprinterdoctor/32/3511_2.png) [@3DPrinterDoctor](https://www.thethingsnetwork.org/forum/u/3DPrinterDoctor)\ **Post date:** [February 19, 2017, 12:13pm UTC](https://www.thethingsnetwork.org/forum/t/otaa-with-lmic-and-arduino-dragino-shield-doesnt-work/4905/8 "2017-02-19T12:13:29Z")
I am having the same issue using the Dragino Pi Hat as a node. About 1 in 10 transmissions actually get passed the join request. I will try adding the line of code mentioned and let you know if that works. ---
**Author:** ![arjanvanb](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/arjanvanb/32/46626_2.png) [@arjanvanb](https://www.thethingsnetwork.org/forum/u/arjanvanb)\ **Post date:** [February 19, 2017, 12:25pm UTC](https://www.thethingsnetwork.org/forum/t/otaa-with-lmic-and-arduino-dragino-shield-doesnt-work/4905/9 "2017-02-19T12:25:14Z")
> [@3DPrinterDoctor](#): > > About 1 in 10 transmissions actually get passed the join request. If “transmissions” refers to sending data, then unless it’s really only sending a few times a year, an OTAA node should not activate itself for each transmission; that’s just a waste of air time. If your node cannot save its state between transmissions then ABP might be a better fit, along with the decreased security of [disabling the frame counter checks](https://www.thethingsnetwork.org/forum/t/abp-node-stopped-working-fixed-by-creating-new-abp-why/3200/7). But going into a low power mode that preserves the activation details is much preferred. As for OTAA: many more debugging steps and background in [OTAA ok, 12h later I get denied, reboot gateway –\> OK again …!?](https://www.thethingsnetwork.org/forum/t/otaa-ok-12h-later-i-get-denied-reboot-gateway-ok-again/2025) (Yes, that’s a long topic…)