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Digital Voice Hotspots

WORK IN PROGRESS - COMMENTS AND CORRECTIONS WELCOMED!

My own notes about configuring the MMDVM_HS HAT digital voice hotspot using the excellent Pi-Star software and the radios which go through it.  This page is really my own notebook, and therefore a work in progress, but I hope it might eventually be a help for others.

Resources

http://www.dstar101.com/

http://www.mdarc.org/activities/repeaters/dstar/linking

 

Configuring the Hotspot

Display

I added a 2.4-inch Nextion display based on information in the Pi-Star Wiki.  

You need to program the display's firmware by downloading a file and copying it to FAT32 formatted micro-SD card.  Choose your preferred display format and Nextion size and download from the .TFT files here.  There are files for the DB2OE, G4KLX and ON7LDS formats.  Although the PD0DIB page connects the display to the RPi, I expect that just the +5 supply is required, but perhaps it's better to terminate the data leads anyway.  Once the display is powered up with the card inserted, you will see it updating the firmware.  You can then power it down and remove the card.

You can connect the display to the MMDVM_HS HAT using the "modem" points.  I added in pins so that I could use the wires from the Nextion without cutting off the pre-supplied sockets.  Connect 0V and +5 V, and TX to RX reversed (i.e. TX display to RX HAT vice versa).

Using the Admin panel with the Pi-Star, select the display as Nextion, and the port as "Modem" as you are using the "modem" connection on the HAT.

Frequency

You need to choose a suitable in-band access frequency.  Mine was set to 431.075 MHz, although after careful checking I found that 431.0745 was closer to producing the correct output frequency.  Nevertheless, 500 Hz at 431 MHz is not a great error (and the device is in an unheated cupboard).

D-Star

Need:
    Your callsign: e.g. G9ABC

Settings:
    RPT1: G9ABC B ("B" is the eighth character, and is B for 432 MHz band)
    RPT2: G9ABC G ("G" is the eighth character, and is for Gateway)
    APRS: E.g. uk.aprs2.net (where should you get this from?)
    IRC: E.g. rr.openquad.net (where should you get this from?)
    Linked to: REF001 C (note that "C" is the eighth character) 
    This is simply the setting to start with.  To change reflector see your radio programming.

There's a list of reflectors here, which lists REF001C as D-Star's MegaRepeater in London.

DMR

Need:
    Your DMR ID

Settings:
    DMR CC: 1
    TS1: Disabled
    TS2: Enabled

Fusion

Settings:
    YSF Network: Room: UK DVMEGA

 

Updating and settings for NTP and SNMP

Updating

To update the pi-star you use two commands, making the disk writeable before running each.  Use PuTTY to log into the RPi from Windows.

rpi-rw
sudo pistar-update
rpi-rw
sudo pistar-upgrade

SNMP and NTP external access

I found that, by default, the security settings didn't allow SNMP or NTP access from devices on the local network.  tp fix this, you need to update the iptables:

rpi-rw
sudo iptables -I INPUT 3 -s 192.168.0.0/16 -p udp -m udp --dport 123 -j ACCEPT
sudo iptables -I INPUT 3 -s 192.168.0.0/16 -p udp -m udp --dport 161 -j ACCEPT
rpi-ro

Resetting SNMP temporary files

If you use SNMP "pass" commands, you may find that these stop working once the disk is read-only.  To reset that, you can use cron to run a job at e.g. 05:00 every day with the commands:

sudo mount -o remount,rw /dev/mmcblk0p2  /
sleep 1
sudo rm -rf /var/lib/snmp/.snmp-exec-cache && sudo ln -s /tmp/.snmp-exec-cache /var/lib/snmp/.snmp-exec-cache
sleep 1
sudo mount -o remount,ro /dev/mmcblk0p2  /

Even then, you will get some breaks in the logging - for example.

Programming your radio - examples

D-Star - Icom IC-7100

Name:
    E.g. "Local hotspot"

Operating Frequency:
    431.075 MHz

DUP:
    -DUP or +DUP, not OFF.  It appears that without duplex set the Icom will send the RPT2 field as "DIRECT*" which the hotspot doesn't recognise.  A "Repeater" style field is required, "CALLSIGN G", where <callsign> is what you programmed into your hotspot.  "G" for gateway.

Filter:
    I have this as 2.

Programming - it's convenient to program a number of channels:
    Set a channel for talking to your hotspot:
        CQCQCQ, G9ABC  B, G9ABC  G
    To link to a particular reflector
        REF001CL, G9ABC  B, G9ABC  G
        Note the "L" for Link.
        Here are some more examples:
        DCS005BL, G9ABC  B, G9ABC  G
        REF006AL, G9ABC  B, G9ABC  G
        REF079AL, G9ABC  B, G9ABC  G
    To unlink from a reflector
        .......U, G9ABC  B, G9ABC  G - 
        Note that the "U" must be in the 8th character position, preceded by spaces.
    To check using the Echo function:
        .......E, G9ABC  B, G9ABC  G - 
        Note that the "E" must be in the 8th character position, preceded by spaces.

Having programmed at least the above, you need to first select a reflector channel you programmed, then press the PTT for about half a second.  Then go back to the "talking" channel.  Your hotspot should remain connected to the chosen reflector.  Listen to check that you are on the expected reflector, and when there is a suitable gap call in.  To change reflector, first select the programmed Unlink channel, half-second PTT press, select the desired reflector channel, half-second press, then back to the talking channel.  It's actually easier to do than described, once you have the hang of it.

This is about the limit of my current knowledge, so comments and corrections are welcome!

DMR - Radioddity GD-77

First, add the new channel, then a new zone (optional), to which the new channel is added.

To select other reflectors, use the Manual Dial function of the radio.

Direct Hotspot
Channel:
  Name: EES2TG9LOCAL
  RX: 439.71250 MHz
  TX: 430.71250 MHz
  Power: High
  Privacy: Off
  RX group list: None
  Color Code: 1
  Contact name: TG9
  Time slot: 2
Channel:
  Name: MMDVM
  RX: 431.07500 MHz
  TX: 431.07500 MHz
  Power: Low
  Privacy: Off
  RX group list: None
  Color code: 1
  Contact name: TG9
  Repeater/Time Slot: 2
Zone:
  Name: GB7EE
  Member: 001:EES2TG9LOCAL
Zone:
  Name: Hotspot
  Member: 001:MMDVM
Contact => Digital Contact
  Name: TG9
  Call ID: 00000009 (8 chars)
  (Group call)
 

 

DMR - Retevis RT3

Direct Hotspot
Channels Information:
  Mode: Digital
  Bandwidth: 12.5 kHz
  Scan List: GB7EE
  Name: EE2T9LOC
  RX: 439.71250 MHz
  TX: 430.71250 MHz
  Power: High
  Admit: Always
  Privacy: Off
  Contact name: Local TG9
  Group list: None
  Color Code: 1
  Privacy: None
  Repeater Slot: 2
Channels Information:
  Mode: Digital
  Bandwidth: 12.5 kHz
  Scan List:
  Name: MMDVM
  RX: 431.075 MHz
  TX: 431.075 MHz
  Power: Low
  Admit: Always
  Privacy: Off
  Contact name: Local TG9
  Group list: None
  Color Code: 1
  Privacy: None
  Repeater Slot: 2
Zone Information:
  Name: GB7EE
  Member: EE2T9LOC
Zone:
  Name: Hotspot
  Member: MMDVM
Contact => Digital Contact
  Name: Local TG9
  Type: Group call
  Call ID: 9
  Receive tone: No
 

 

Fusion - Yaesu FT-70DE

Your callsign:
    G9ABC

 

 
Copyright © David Taylor, Edinburgh   Last modified: 2017 Dec 30 at 10:53