Repeater Builder STM32-DVM

RB_STM32_DVM
Version 1 (Green Board) Schematic & Board Layout
Version 2 (Red Board) Schematic & Board Layout
Version 3 (Blue Board) Schematic & Board Layout
Version 4 (Black Board) Schematic & Board Layout

*** Please Read***There are times when production cannot keep up with incoming orders. I strive to have orders shipped NO LATER than 10 days from the order date.

Orders are processed and shipped in chronological order. First in - First out.

You will get a shipping notification from the USPS with a tracking number when your order ships.

THANK YOU for your understanding and continued patronage.

Hamvention Break --- May 15^th thru May 18^th 2025

I plan to be at the Dayton Hamvention Tursday May 15^th through Sunday May 18^th.

Here is a photo of where we will be in the Tailgating area:

(click for larger image)

Horse Track Tailgating
Space Number
7727

Orders placed during this week will be shipped in the order they were placed when I return the week of May 19^th as stock allows.

Thank you for your patience.

The NEW Version 4 is currently in production and we are actively shipping orders!!!

Digital Modes Currently Supported:
Older V1&V2 boards:
Digital Mobile Radio (DMR) - D-Star
Yaesu System Fusion (YSF) - P25

The V3 board adds NXDN to the protocol list.

The V4 board adds a LED for the "FM" analog controller mode.

Click Here for
New FAQ Page

The RB_STM32_DVM is yet another Multi-Mode Digital Voice Modem that gives new life to analog repeaters by allowing them to become digital capable. The STM32 has an on-board microcomputer, so there is no need for a separate Arduino or other processor board. This board, plus a platform running MMDVMHost is all that is required.

Two chains of low-pass filtering. (One for TX, one for RX) These filters are a 3 pole filter with a "knee" of approximately 4kHz.
25 turn potentiometers for fine Receive and Transmit Audio level adjustment.
An easy to solder DB-9 for connection to the host repeater. Includes mating connector and metalized hood.
RSSI support built on-board.
New 'clip' circuit to help with RX level adjustment.

Links to instructional videos: Thanks to Craig Gagner W1MSG

A video on how to adjust audio levels: https://youtu.be/dYBRPLysazg

Info on the "expert" settings of PiStar: https://www.youtube.com/watch?v=zzvRVaoIuXg

There are several STM32_DVM versions to choose from, including options and "combo" kits:

STM32_DVM_PiHat:

Special Limited Time Price - $95

This version is customized to be plug-and-play with a Raspberry PI 2/3/4 micro computer board. (The RPI4 is overkill for the MMDVM project) Combined with one of our custom cases, (optional) it makes for a nice, neat compact package.

STM32_DVM_PiCase:

Special Limited Time Price - $10

This case is designed to cover your Raspberry PI 2/3 with the STM32_DVM installed.
NOTE: Will NOT work with the RPI4

Complete Raspberry Pi3 / STM32_DVM Combo:

Special Limited Time Price - $325

This is a complete DVM package which includes:

STM32_DVM_PiHat
Raspberry Pi3 model B(+) Computer (with heatsinks)
Custom Transparent Case
Pre-programmed 16GB micro SD card - MW0MWZ's PiStar image
5v@3A micro USB power supply
Premium package support

The above comes pre-assembled and ready to connect to your repeater.

Note: The pre-loaded software is freely downloadable from - https://www.pistar.uk/
We are charging for our time to load the software on the card and assemble the package.

STM32_DVM_NanoPi:

Special Limited Time Price - $300

Schematic and board layout

This is a complete DVM package:

Aluminum Enclosure
.96" OLED Display
NanoPi Microcomputer (with heatsink)
Pre-programmed 16GB micro SD card - MW0MWZ's PiStar image
Internal 5v@3A DC-DC converter power supply

The above comes pre-assembled and ready to connect to your repeater.

Note: The pre-loaded software is freely downloadable from - https://www.pistar.uk/

Setup instructions

STM32_DVM_USB:

Special Limited Time Price - $110

This is a modem board version for folks that aren't running MMDVMHost on a Raspberry Pi. This version requires an external platform running MMDVM host, however instead of plugging directly onto a Raspberry Pi host platform, it connects to the host platform just like other vendor's two piece (filter/processor combo) version via a USB cable.

A 3D printable case for the USB version board

DC-DC Converter:

Special Limited Time Price - $8

This is an optional DC-DC converter module for the V3 & Greater boards ONLY that allows powering of the DVM and Raspberry Pi though the radio interface connector pin 9. Maximum input voltage is 24V DC.

Installation requires soldering.

WARNING: Do NOT connect a 5v supply to the Raspberry Pi's power jack with this module installed. It does not like to have power on its output with no input.

Interface Cables

We now offer cables to connect our STM32_DVM boards to popular radios/repeaters

Duplex Cables:
For use with repeaters.
These cables are approximatley 18" long.

DB-25 for Bridgecom BCR series repeater **
DE-15 for Yaesu DR-1X repeater ***
DB-25 for Kenwood TKR-x50 series repeater
Dual DB-25 for *TWO* Kenwood TK-8180 radios
Single 16 pin connector for Motorola R1225
Dual 16 pin connectors to turn *TWO* Motorola mobiles into a repeater
Dual 6 pin Mini DIN connectors to turn *TWO* 9600 baud capable mobiles into a repeater
DB-25 for ICOM FR-4000 series repeater
DB-25 for ICOM FR-6000 series repeater

** - ~36" long
*** - Will only work with ORIGINAL DR-1X's, NOT refurbished units or DR-2's.

Simplex Cables:
For use with simplex radios to build "High-Power" Hotspots.
These cables are approximatley 18" long.

Motorola 16/20 pin option connector
6 Pin Mini-DIN - for radios with 9600 baud packet connectors
DB-25 for Kenwood TK-8180 radio

All of our products come with courteous and friendly customer service. While product documentation is continuously under development, the user manuals for these products will follow in the same lines as the rest of the RB products in being straight forward and thorough.

I am in the process of assembling a fairly broad collection of connection diagrams for various repeaters and simplex radios. These will all be published on-line for folks to download, easily make the necessary connections to their radio, and configure their software to be on the air with the new digital modes easier than ever before.

My hope is that these products help more people get started with the new and expanding digital modes and their advanced capabilities.

Ordering information:

Secure PayPal Ordering - Use the "Add to Cart" buttons above to make your selections.

We are NOT responsible for lost or stolen packages.
All shipments are shipped via USPS with a tracking number to the address provided by PayPal.
We have no control over your package once it is placed in the USPS outgoing mail slot.

For more information, Please contact Scott either via e-mail or by phone (814) 444-9460 during reasonable hours EST.

Official Product of Scott Zimmerman / Repeater Builder
Inspired from a similar design: github.com/wojciechk8/MMDVM_pog
Low-pass filter design by SQ6POG
Images property of Repeater Builder.
Logo Design by Elisha Zimmerman KB9WCX
HTML May 3,2023- N3XCC