Pi-Star D-Star Hotspot, Part 2: Pi-Star Configuration and D-Star Registration

You assembled the hardware and reached the Pi-Star dashboard in Part 1. Part 2 configures the hotspot for D-Star, links it to a reflector, and walks through D-Star gateway registration. None of this requires your Icom radio yet — that is Part 3.

Register Your D-Star Callsign

D-Star gateways require one-time registration. Register on any gateway once; approval covers the global D-Star network. Complete this before expecting reflector QSOs to work.

Step 1: Submit your registration

1. Browse to regist.dstargateway.org.
2. Click Register under New User?
3. Enter your call sign in UPPER CASE.
4. Enter a valid email address.
5. Choose a password and record it securely.
6. Read the agreement, select YES, and submit.
7. Wait for the approval email. If none arrives, try logging in — approval may already be complete.

Already registered elsewhere? Do not submit a second request. One registration works across all gateways.

Step 2: Create terminal entries (critical)

After approval, log in and create two terminal entries:

1. Terminal 1 — Check box 1. In Initial, enter a single space (press space once). Do not check AccessPoint.
2. Terminal 2 — Check box 2. In Initial, enter Z. Check AccessPoint.
3. Click Update.

Terminal 1 is your main radio identity. Terminal 2 with AccessPoint is what hotspots and gateway software expect. Skipping the space in Terminal 1 or forgetting AccessPoint on Terminal 2 is the most common registration mistake.

Video walkthroughs: official registration instructions. Verify registration with pistar.uk/d-star_regcheck.php.

Configure Pi-Star for D-Star

All settings live in the web dashboard at http://pi-star.local/admin/. Open Configure → Configuration and work top to bottom, clicking Apply Changes after each section. These steps assume a personal simplex UHF hotspot running D-Star only.

Choosing a Simplex Frequency

A hotspot is a simplex node: your radio and the MMDVM board transmit and receive on the same frequency with no repeater offset. Pick a frequency before you fill in Radio Frequency below — it must match the DV memory you program in Part 3 exactly.

UHF (70 cm) hotspots

Most Pi-Star D-Star builds in the US run UHF. 438.8000 MHz is the de facto hotspot simplex across much of the country — quiet enough for digital use and far from the 446.000 MHz national FM simplex calling channel. If several operators in your area already use 438.8000, pick another unused simplex slot a few kHz away (for example 438.8125 or 438.8250) so your transmissions do not collide on the air.

1. Check your local band plan. The US 70 cm band mixes repeater segments, weak-signal, and simplex. Your frequency must be inside a segment where you are allowed to operate at your license class and that is not reserved for repeater inputs or outputs in your region. Your club or state frequency coordinator is the authoritative source.
2. Listen before you transmit. Tune a handheld, mobile, or SDR to the candidate frequency for several minutes. Repeaters, other hotspots, and FM simplex traffic should be absent or rare.
3. Stay off repeater pairs. Do not park a hotspot on a known repeater output (commonly 443–449 MHz in many US areas) or you will key up someone’s local machine every time you use the reflector.
4. Verify TX with a second receiver. After Pi-Star is running, confirm the hotspot actually transmits on the frequency you configured — not a typo or an offset left over from a repeater template.
5. Write it down. You will enter the same value in Pi-Star and in CS-51/CS-52; a mismatch is the most common reason a configured hotspot appears deaf.

VHF (2 m) hotspots

If your MMDVM hat is VHF-only, use a 2 m simplex frequency permitted in your area (examples: 145.6000 or 145.6700 MHz) and set RPT1 module C in the D-Star section below. Avoid 146.520 MHz (national FM calling) and any frequency your local repeaters use.

Controller Software

1. Controller Software — MMDVMHost.
2. Mode — Simplex Node (unless running a duplex repeater hat).
3. Click Apply Changes.

MMDVMHost Mode

1. Enable D-Star Mode.
2. Set RF Hang Time and Net Hang Time to at least 5 seconds (10 is a safe default).
3. Disable unused modes (DMR, YSF, P25, NXDN) on a Pi Zero to save CPU.
4. Click Apply Changes.

General Configuration

1. Node Callsign — Your FCC call sign only (example: KC4SMH). No suffixes.
2. Radio Frequency — Simplex frequency in MHz (example: 438.8000). Must match the radio memory in Part 3.
3. Latitude / Longitude / Town / Country — Your QTH for gateway maps.
4. Radio/Modem Type — Match your hardware (MMDVM_HS_Hat, MMDVM_HS_Dual_Hat, DVMEGA, etc.).
5. Node Type — Private for a personal hotspot.
6. System Time Zone — Example: America/New_York.
7. Click Apply Changes.

D-Star Configuration

1. RPT1 Callsign module — Band letter matching your frequency:
   • B = 70 cm (UHF) — most ID-51/ID-52 builds
   • C = 2 m (VHF)
   • A = 23 cm
2. Default Reflector — ARRG.US operators commonly use XLX102 module B. Pick any XLX module on the array that fits your operating habits.
3. Link at startup — Startup for automatic connect on boot, or Manual to link from the dashboard.
4. Click Apply Changes.

Display and verification

1. Under Display Options, set OLED type if applicable (commonly OLED 0.96).
2. Reboot from the admin menu.
3. Open Admin. Confirm D-Star and D-Star Net are green.
4. The dashboard footer should show your linked reflector (example: XLX102B).

Troubleshooting