Error Updating Helium Hotspot Location: wrong_txn_fee

The first time you set up your Helium miner, the location has to be specified. The user is able to specify the location and there are considerations around which Hex to pick for instance.

Fast forward a few weeks and you realize that your miner is not earning very much HNT. As a result you might want to move your miner to another location.

A miner can be moved easily. However if you move by more than a Hex, the location will have to be updated. This post describes a common problem encountered when doing this and prescribes a solution.

The Problem

If you’re updating the location of your Helium Hotspot using the Helium App, you might run into an error that says:

Failed Transaction

Unable to assert location for < Hotspot_name > for reason {invalid, wrong_txn_fee}

Reason

Here’s the reason for the error and how to solve this problem.

When you update the location of your Helium miner you might notice that it notifies you of the fee that’s required for the transaction. The normal fee for this transaction is 1,000,000 Data Credits which is approximately $10. Additionally there is a 55,000 data credit fee. The first location assertion is usually covered by Hotspot maker and any subsequent location changes are charged from your Helium wallet.

The Helium app notifies you of the amount that you will be charged and sometimes it states an incorrect Data Credit fee amount. For instance it might say 1 DC which is incorrect. However there’s nothing you can do to override this and as a result it results in a wrong_txn_fee error message.

You can also check your Hotspot transactions. If there’s nothing there related to the miner you want to relocate, then the location will not be updated.

Solution

The only way to solve this problem is to wait for a bit and try asserting your location again. I had to try a couple of times until it charged me the correct transfer fee of 1,000,000 Data Credits. At this time it turned into a Hotspot transaction and the location was updated within 30 minutes in the app.

Helium Assert Location

You will now also see the asserted location confirmation associated with your miner in the Helium Explorer. Also if you look at the details of the transaction you can see that your wallet has been charged a Staking Fee which is the same as the data credit charge mentioned. It might take a few hours before the transmit scale of the miner is updated to reflect that at the new location.

Background

What is Helium?

Helium is a LoRa network that connects IoT devices. It consists of gateway devices called hotspots or miners connected to one another over the internet. Data from IoT devices is transmitted to hotspots or Helium Miners and then across the Helium network.

Helium mining results in earnings for the hotspot host by way of tokens called HNT. This incentivizes the growth of the network. At the time of writing there are over 900,000 active miners globally. This number continues to grow.

How do I mine Helium?

In order to mine Helium you need dedicated hardware called a Helium hotspot. There are many hotspot vendors including Rak, Nebra and others. The hotspot is like a wireless access point that is used to communicate with sensors and other hotspots. It is also connected to the internet over Ethernet or Wi-Fi.

Helium devices and the network are relatively new. Furthermore, the network is growing very rapidly and often runs into technical issues. We anticipate there to be fewer errors as the network stabilizes over time.