Sensor ID is already registered

Hi, @ricki-z, Can you release chip id esp8266-14070653?
I’m unable to register it due to a ‘this sensor is already registered’ error.

THX, from Hungary

@Rico was there an owner of the device before you? The chipID is registered to a person with an email I can’t assign to you.

@Aisha_B Hello, was the device pre-owned by another person?

@Istvan_Pinter You’ve deleted the registration today. Can I restore this registration?

Hello Ricki!

Sorry about the delay answer, but i was sleep! :slight_smile:
Well, i forgot about the wrong discuss registration email, it was my gmail acc. Yes the other mail is a mirrored syntax mail: pint…@pint… Yes, please delete the chipid from the database, bcoz i’ve chosen a wrong type of device, and i want to registrate it again!


Hey @ricki-z, I received some pre-built sensors from the OpenHub of Louvain-la-Neuve to monitor air quality in Brussels. I had no issues with the other ones, but I’m unable to register this one due to an error, and unfortunately, I can’t retrieve information about its previous owner. Could you provide me with the sensor ID so I can retrieve the data from the archive? However, there’s still a problem because it’s monitoring a different location than originally intended if already registered… Thanks in advance !

Hi @ricki-z , I’m a teacher and we are loaning some sensors from our local government for a school project, so I can imagine that the sensor was registered by another person before.

@Istvan_Pinter I’ve released the chipID now.

@Rico That was enough information to check that we are talking about the same sensor (the former owner mentioned the project and the place). So I’ve released the chipID and you can register ist again.

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Very BIG THANK YOU! :slight_smile:

@Aisha_B I’ve released the chipID. Registration should be possible again.

Hello @ricki-z,

I have two sensors out of a series of 40, which give the famous “already registered” message at registering. The registering was not done by me, otherwise they would be in my list on
One is Chip-ID 6545239, which is not online on Madavi, and can be released, so I can start using it.

The other is Chip-ID 3072868, which is recently ON-LINE ON MADAVI, .
It was online last year in october for +/- 2 weeks, and is again online since 28/4/2024.

It is NOT MINE, since my sensor was only assembled in march this year, and was never connected before. My sensor generates AirRohr-3072868 as SSID when in AP mode.
There are clearly two sensors with the same Chip-ID. How can this problem be solved ?

Hello there @ricki-z ! I have another device which was registered by a student (from Aston University) for their project, but now I would like to release it and re-register it. It has been offline for some time and just set up again today. Could you please release chip no. esp8266-13451548?
Thank you!!

@doctorluz I’ve released the chipID.

@Rik_Drabs One case creating duplicate chipIDs are typos when registering a sensor. This may be the cause for the first sensor. I’ve released this chipID (6545239).
By the second one you should check the chipID on the sensor internal webpage when the sensor is connected to your wifi. It seems like the chipID isn’t shown correctly in some rare cases.
But it could also happen the the chipIDs are really the same. The chipID is the second part of the MAC address. The first 6 byte are the manufacturer ID. And a manufacturer can have more than one of these IDs, as the other 6 bytes will “only” be enough for 16 mio. devices. It’s very unlikely that two ESP8266 used for our project will have the same chipID, but it may happen … The only solution in this case is using another ESP8266.