DINAH

Under Construction

Announcing DINAH (SM)

DINAH (SM) is a single board implementation of DINAH using surface mount parts for the IC, FET, diodes, resistors and capacitors.  If you have surface mount soldering skills and are interested in constructing a Beta unit, please contact me using the email address on my QRZ page.

Overview

DINAH (DIN connector based Allstar interface for Hams) is a kit construction project that implements a radio interface to a Raspberry Pi running Allstar software.  An Allstar node can be implemented using DINAH, a UHF or VHF radio with a packet (or data) interface and a Raspberry Pi running the Allstar program.

Unlike the full-featured and more flexible Allstar radio interface solutions from sources such as HAM VOIP, Repeater Builder, DMK , Masters Communications, etc – DINAH utilizes a modified low cost USB FOB and is designed specifically to interface  to the 6 pin DIN connector commonly used for the packet (or data) connection on ham radio VHF and UHF radios.  Because this packet interface is fairly standard, DINAH requires no additional gain or potentiometers in the audio paths.  Required audio gain settings can be achieved from within the Allstar program.  An inexpensive standard off-the-shelf cable with 6 pin miniDIN male connectors on both ends is used to connect DINAH to the radio.  Thus the builder does not have to build an interface cable.  However, the DINAH PCB includes optional jumpers and parts locations to permit the builder to insert fixed attenuation in the audio paths, select 1200 or 9600 audio and enable CTCSS for additional interfacing flexibility.

DINAH measures only 2 inches long and 1 inch square (50mm by 25mm).  It has a built-in male USB connector to plug into a Raspberry Pi (2 or 3) on one end and a 6 pin female DIN connector (to connect to your radio) plus red (PTT) and green (OK) status LEDs on the other end.

Features and Expectations

Key Features

  • Detailed step-by-step construction manual with pictures
  • Uses low cost, proven Sanwu CM-108 USB FOB
  • Small, portable, USB-powered
  • Rugged, RFI-resistant metal enclosure
  • RFI filter capacitors
  • Uses standard low-cost 6 pin male-to-male miniDIN cable
  • Interfaces to standard packet (data) interface on many VHF/UHF radios
  • Jumpers and extra parts locations facilitate custom configurations
  • 3D printed plastic enclosure ends provided to minimize mechanical assembly effort
  • Blank metal end caps included for modification and use in the event of RFI issues

Setting Expectations

  • What’s missing from this miniature design?
    • Intended for use with VHF and UHF radios having “standard” packet (or data) 6 pin DIN connector.
      • No audio gain provided for custom configurations.
      • Audio attenuation set by fixed resistors – no potentiometers provided.
      • Jumpers and extra parts location facilitate limited custom configurations
  • Degree of mechanical difficulty – easy (if you use the 3D printed plastic end caps)
    • The DINAH boards fit snuggly in the metal enclosure. You may need a file or sandpaper to adjust the boards for a snug fit in the case
    • If you decide to use the metal end caps, you will need to refer to the end cap drawings in the appendix to mark, drill and cut the required holes and slot.
    • STL drawings of End Caps are available for custom configurations
  • Degree of soldering difficulty – Difficult to Medium
    • Difficult Part– Modifying the USB FOB requires soldering five 30 gauge wires to tiny pads and IC pins. You will also be stripping Teflon insulation from 30 gauge wires so you will need an appropriate wire stripper.  You will need a good light, a steady hand and probably need some type of magnification to do this part of the construction successfully.  The use of the DINAH FOB carrier board does help in securing and terminating these added wires.  Read through the procedure for modifying the FOB and if it seems to be beyond your skill level consider ordering the kit with the partially assembled FOB Carrier board.
    • Medium Part – Assembly of the DINAH Interface board is standard through-hole soldering of leaded components.

Order Info

DINAH will be available as a complete parts kit, partially assembled parts kit or completely assembled.

Assembly

DINAH is implemented using two printed circuit boards called the Interface board and the Carrier board.  The Carrier board is used as a mounting fixture for the USB FOB and a connection point for signals from the modified FOB.  The Interface board contains the circuitry required to interface with the electrical requirements of the 6 pin miniDIN jack on your radio.  This jack is variously called “data”, “packet”, “auxiliary” etc.  It is a “quasi” standard used by many of the ham equipment manufacturers.  Using this interface means that a standard, low cost miniDIN cable can be used to connect DINAH to the radio.  The user does not have to build this cable.  Also, since the packet interface is “standardized”  no adjustments for audio levels are required on the DINAH interface board.  These adjustments can be made in the Allstar program.

INTERFACE BOARD

CARRIER BOARD

Assembly of the Interface board is pretty standard through-hole soldering.  However, assembly of the Carrier board is considerably more difficult.  It requires soldering three 30 gauge solid core wires to 2 IC leads and a tiny solder pad on the USB FOB assembly.  It requires a soldering pencil with a small tip, small diameter solder, a steady hand and excellent eyesight or a magnification device.  If your soldering skills are not at this level, the DINAH kit is available with the carrier board mostly assembled for you for additional cost (you solder on the through-hole pin header and LED).

The two boards plug together using a 6 conductor pin header and are inserted into a low cost aluminum extruded enclosure about 2″ long by 1″ square.

DINAH Extruded Case

CARRIER AND INTERFACE BOARDS PLUGGED TOGETHER

The DINAH kit contains all of the parts required to build the device as well as the 3 foot miniDIN cable. It includes blank metal end caps for the enclosure (you add the required cutout and holes) as well as a set of plastic 3D printed end caps which can be used instead of the metal end caps (at the builders discretion). It does not include the Raspberry Pi (2 or 3), the Pi power supply or a case for the Pi.

DINAH Kit Parts

A DINAH kit parts list can be downloaded by clicking HERE.

A comprehensive step-by-step construction/assembly manual is supplied as a download from this site (no printed manual is supplied). Click HERE to download the manual.

A guide by KG8MM to setup and configure the HamVOIP Allstar distribution  for DINAH can be downloaded HERE .

3D printed plastic end caps are also provided with the DINAH kit.  They require some cleanup of the holes and slots before use.  Even after cleanup, they still look “3D printed”.  If you have access to your own 3D printer, STL files of the endcaps are available.  Click HERE for the STL files.  Blank painted aluminum end caps are also provided with the kit. Dimensioned drawings can be found in the appendix of the construction manual to assist you in adding the required holes and slot.

Support

Support of the DINAH hardware is provided using  groups.io .  The purpose of the DINAH group is to serve as the main hardware support source and discussion group for hams building and using the DINAH Allstar Radio Interface. Support of the Allstar distribution you install in your Raspberry Pi and use in conjunction with DINAH is best obtained from the source of the Allstar distribution (i.e. allstarlink.org or hamvoip.org). You need to join the DINAH group in order to post messages.  The first posting from you as a new user must be approved by the moderators – thus there may be a delay between the time of your original post and its arrival in groups.io.
Click HERE to open the DINAH group.
Subscribe to the group by providing your email address below and clicking on the Subscribe box:

Schematics

Here are the schematics of the two printed circuit boards used in DINAH.  Click on the links for higher resolution PDF versions.

DINAH Interface Board Rev B

DINAH Carrier Schematic Rev A

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