Table of Contents

Replacing and Reimaging the Nebra Indoor and Outdoor EMMC Key / SD Card #

Required Tools: #

• A Phillips Head Screwdriver or plastic pry bar for the Nebra Indoor Miner or allen key set for Nebra Outdoor Miner
• Strong fingernails, tweezers, or needle-nose pliers to remove the old SD card
• A Micro SD Card Reader
• A 64gb (or larger) A2 micro sd card
• A Micro USB 2.0 Cable

Required software: #

• Balena Etcher
• Balena Raspberry Pi Image
• Raspberry Pi USB Boot

Inside the Nebra Helium Miners: #

Contents of the Nebra Indoor Miner: #

Contents of the Nebra Outdoor Miner: #

• 1.) 9-16V @ 15W DC 6.5MMx2.0MM Barrel Jack
• 2.) Ethernet Connector
• 3.) LED Indicator
• 4.) Interface Button
• 5.) 4G / LTE Module Connector
• 6.) Sim Card Slot

How to replace the SD Card #

Step 1: Acquire the config.json file from the EMMC Key: #

• Download and install Raspberry Pi USB Boot, you’ll need this to boot the compute module as a usb file system
• Identify the and adjust jumper pins on the CM3 daughterboard for programming mode
• 
  • 5.) Micro USB Port used for Imaging
  • 7.) JP4 USB Jumper - Used to switch between normal operation and flash mode, ensure it is in position 1-2 for normal operation and 2-3 for programming.
  • 8.) JP3 Power Jumper - Allows the module to be powered from the Micro USB connector. Only connect when programming from PC and ensure mainboard is not connected.
• Move the JP4 Jumper to position 2+3
• Plug in a usb cable and run the Raspberry Pi USB Boot utility
• Open your file explorer and you’ll see a drive called “resin-boot”. Retrieve the “config.json” file from the directory
• Unplug the usb cable and reset the JP4 jumper to position 1+2

Step 2: Flash new sd card with the Balena Raspberry Pi CM3 Image: #

• Download and extract Balena Raspberry Pi Image
• Using Balena Etcher select the recently extracted .img file and your new microsd card as the target device
• Select Flash

Step 3: Copy the original config file to the new sd card: #

• Unplug your micro sd card reader and plug it back in after finishing step 2
• You’ll now see a drive in explorer called “resin-boot”.
• Copy the config.json file you copied earlier and overwrite the config.json file that is already on the sd card.

Step 4: Install the new sd card and reassemble the Nebra Miner: #

• Install the SD card in the slot in which the EMMC key was previously.
• Reassemble the miner
• When first powering the newly flashed Nebra Miner, plug it in with ethernet for 20-30 minutes before setting up wifi connections again.

Step 5: Profit? #