Home | Log | Guides | Software | Hardware | Discussions | Shop | Contact Me | Donate

Build Recipe: Handheld RNode

This build recipe will help you create an RNode that is suitable for mobile and handheld operation, and offers both wireless and wired connectivity to host devices. It is also useful for permanent installation indoors, or even outdoors, as long as it is protected from water ingress and direct sunlight.

Depending on the board you use, it will offer a workable frequency range between 420 and 520 MHz, or 820 and 1020 MHz, and a maximum TX power of 17 dBm (50 mW).

Handheld RNode dimensions

Table of Contents

  1. Preparation
  2. Supported Boards
  3. Materials
  4. Print Parts
  5. Install Tools
  6. Firmware Setup
  7. Assembly

Step 1: Preparation

When you have completed this recipe, you will end up with a fully-featured RNode device, similar to the one pictured below. To make it as easy as possible to complete this guide, make sure to read it all in its entirity before starting. I also recommend you familiarise yourself with the required materials, and the software tools needed for the setup.

Completed Handheld RNode

A completed Handheld RNode

To complete this build recipe, you will need access to the following items:

Step 2: Supported Development Boards

This RNode design is using a LilyGO LoRa32 v2.1 board, in either the 433 MHz, 868 MHz, 915 MHz or 923 MHz variants. It seems that the 868, 915 and 923 MHz variants are in fact completely identical, and all offer a frequency range between 820 and 1020 MHz. The 433MHz variants offer a frequency range between 420 and 520 MHz.

These boards are also sold under many different "brand" names other than LilyGO, but using the images below, you should be able to identify the correct ones.

It is easiest to obtain the version of the board with an u.FL (sometimes also labeled IPX or IPEX) antenna connector, instead of the SMA connector. This version comes with an SMA to u.FL pigtail, which is installed into the 3D-printed case. If it is not possible to obtain this version, you can use the one with an SMA connector, either as is, or by removing the SMA connector, and using the on-board u.FL connector instead.

If you do not wish to use the 3D-printable case included in this guide, it does not matter which version you get. There is no functional difference between the boards with SMA and u.FL connectors.

Compatible board

The correct board version for this RNode build recipe

If you want to use the case provided for this build guide, and you have the version with an SMA connector, you will have to desolder the SMA connector, and activate the u.FL connector instead (it's already installed on all the boards, just not activated on the SMA connector versions).

To activate the u.FL connector, you will just have to "rotate" the small resistor next to the antenna connectors by 90 degrees, so it "points" at the connector you wish to use.

Please note that the "resistor" is actually just a zero-ohm jumper. If you don't feel like fiddling around with small components, you can simply remove it, and bridge the relevant gap with a blob of solder.

Refer to the following two pictures to locate the resistor that needs moving:

Before desoldering After desoldering

Before and after removing the SMA connector and moving the resistor

You will also need to dismount the OLED display from the small acrylic riser on the board, and unscrew and discard the riser. Be careful not to damage the display or ribbon cable while doing this. The OLED display will be mounted directly into a matching slot in the 3D-printed case.

As before, if you do not want to use the 3D printed case supplied here, it's probably much easier to keep the display on the board, and you can simply skip this step.

Step 3: Obtain Materials

In addition to the board, you will need a few other components to build this RNode.

Step 4: 3D Print Parts

To complete the build of this RNode, you will need to 3D-print the parts for the casing. Download, extract and slice the STL files from the parts package in your preferred software.

All files are dimensioned to fit together perfectly without any scaling on a well-tuned 3D-printer.

The recommended layer height for all files is 0.15mm for FDM printers.

Step 5: Install Tools

To install and configure the RNode Firmware on the device, you will need to install the rnodeconf program on your computer. This is included in the rns package, that can be installed using the pip package manager:

pip install rns

When the rnodeconf program is installed, you can continue to the next step.

Step 6: Firmware Setup

Once the rnodeconf program is installed, we will use it to install the RNode Firmware on your device, and do the initial provisioning of configuration parameters. This process can be completed automatically, by using the auto-installer. Run the rnodeconf auto-installer with the following command:

rnodeconf --autoinstall
  1. The program will ask you to connect your device to an USB-port on your computer. Do so, and hit enter.
  2. Select the serial port the device is connected as.
  3. You will now be asked what device this is, select the option A Specific Kind of RNode.
  4. The installer will ask you what model your device is. Select the Handheld RNode v2.x option that matches the frequency band of your device.
  5. The installer will display a summary of your choices. If you are satisfied, confirm your selection.
  6. The installer will now automatically install and configure the firmware and prepare the device for use.

Please Note! If you are connected to the Internet while installing, the autoinstaller will automatically download any needed firmware files to a local cache before installing.

If you do not have an active Internet connection while installing, you can extract and use the firmware from this device instead. This will only work if you are building the same type of RNode as the device you are extracting from, as the firmware has to match the targeted board and hardware configuration.

If you need to extract the firmware from an existing RNode, run the following command:

rnodeconf --extract

If rnodeconf finds a working RNode, it will extract and save the firmware from the device for later use. You can then run the auto-installer with the --use-extracted option to use the locally extracted file:

rnodeconf --autoinstall --use-extracted

This also works for updating the firmware on existing RNodes, so you can extract a newer firmware from one RNode, and deploy it onto other RNodes using the same method. Just use the --update option instead of --autoinstall.

Step 7: Assembly

With the firmware installed and configured, and the case parts printed, it's time to put it all together.

  1. Insert the SMA to u.FL pigtail adatper into the matching slot in the top part of the bottom shell. Make sure it lines up with the internal hex-nut cut-out in the bottom shell, as the hex nut of the adapter will get pulled into this cut-out, and thereby self-lock, when an antenna is connected. You can optionally mount a locking nut on the exterior thread of the SMA connector when the case has been completely assembled.
  2. Thread the cable of the SMA to u.FL pigtail adapter into the matching grove, and run it out of the bottom opening.
  3. Mount the power-switch slider into the matching slot, in the bottom-left part of the bottom shell.
  4. With the SMA connector and power switch mounted, slide the board into the bottom shell, such that the power switch of the board mates with the slot in the already installed power-switch slider. Click the board into place in the bottom shell.
  5. Optionally mount the NeoPixel LED:
  6. Carefully mount the OLED display in the rectangular slot in the middle part of the top shell.
  7. While ensuring that all internal cables stay within their routing groves, place the top shell on top of the bottom shell, making sure that the screw-mounting holes line up.
  8. Mount the 6 M2x6mm screws into the mounting holes, until the two shells of the case are tightly and securely connected.
  9. Flip over the device.
  10. Connect the male u.FL connector to the female u.FL socket on the board.
  11. Optionally, connect the male JST connector of the battery to the female JST connector on the board.
  12. Fit the battery door into place.

Congratulations, Your Handheld RNode is now complete!

Flip the power switch, and start using it!

This website is running on a 100% solar powered server


Unless otherwise noted, everything here is put into the world under a CC BY-NC-SA 4.0 license.
Feel free to share and remix, just remember the attribution.