A number of people are reporting this problem with Nebra Rock Pi miners where it states Miner RPC Unavailable. RPC stands for Remote Procedure Call. RPC allows a user to perform actions on a machine while being on another machine. It can also apply to the same machine but in a different process.
According to Wikipedia:
“In distributed computing, a remote procedure call (RPC) is when a computer program causes a procedure (subroutine) to execute in a different address space (commonly on another computer on a shared network), which is written as if it were a normal (local) procedure call, without the programmer explicitly writing the details for the remote interaction.”
This appears to be an error in the code and we expect someone at Nebra will sort this issue out soon. It is an issue that affects many users.
For the time being until they do, there are two solutions to the problem:
- Restart your miner and see if this fixes it. You might have to try this a couple of times as sometimes it doesn’t work on the first attempt
- If the above doesn’t work, contact Nebra support. They are able to fix this remotely.
Background
What is Helium?
Helium is an IoT network that connects devices like dog tags, environmental sensors, bike trackers and more. It consists of gateway devices or hotspots connected to one another over the internet. Data from IoT devices is transmitted to hotspots or Helium Miners and then across the Helium network. Hotspot owners are rewarded with tokens called HNT for hosting mining devices in their homes or on their property. The less dense an area the higher the potential for token earnings. Consequently placing a miner in downtown Manhattan will not earn the host a lot.
How to mine Helium?
In order to mine Helium you need dedicated hardware called a Helium hotspot or miner. 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 very new. Furthermore, the network is growing very rapidly and often runs into technical issues. We have attempted to document our troubleshooting procedures in blog posts.
What is the Rock Pi Miner?
The Rock Pi miner is the second generation miner from Nebra with the following specifications
Technical Specifications
| Specification | RockPi Indoor Hotspot |
|---|---|
| Dimensions | 94x70x53 mm (Excluding Antenna) |
| Weight | 353g |
| Power Requirement | 12V 2.5A USB-C |
| Maximum TX Power | 24-27dBm |
| Network Connectivity | 1GBit Ethernet, 2.4GHz 802.ac Wi-Fi, Bluetooth 4.2 |
| Antenna Connection | RP-SMA Female |
| Rated Ambient Temperature | 20-30 degrees Celsius |
| Base SOM | ROCK Pi RK3399 Processor |
| CPU Specification | Dual Core Cortex A72 1.8 GHz and Quad Core Cortex A53 1.4 GHz |
| High Endurance Storage | 32 GB |
| RAM | 2 GB |
The USB-C power connector is a new feature as well. I lost one of my power adapters while moving the miner and it was challenging to find a replacement. The USB-C is easier to replace.
There are many similarities between the first and second generation of Nebra miners. It is very disappointing that the Wi-Fi connectivity hasn’t been upgraded to include the 5 GHz band. Instead connectivity is only on the 2.4 GHz frequency band. This is a deficiency relative to other miners like the Rak.
Other Helium Troubleshooting Guides:
- How to reset a Helium Miner
- Bobcat Miner Offline and not Syncing
- Browan MerryIoT SD Card Not Detected