birdcage/CLAUDE.md

Winegard Trav'ler

Control a Winegard Trav'ler motorized satellite dish via RS-485 for amateur radio satellite tracking.

Project

• Package: travler-rotor (installed via uv sync)
• CLI entry point: travler-rotor (init / serve / pos / move)
• Source layout: src/travler_rotor/ (src-layout)
• Original upstream: Trav-ler-Rotor-For-HAL-2.05/ — Gabe Emerson's scripts, kept as reference (do not modify)

Build & Lint

uv sync                           # Install deps + package
uv run ruff check src/             # Lint
uv run ruff format --check src/    # Format check
uv run travler-rotor --help        # CLI smoke test

Architecture

protocol.py   — FirmwareProtocol ABC + HAL205Protocol / HAL000Protocol
                Serial I/O owned here. Each firmware version is a subclass.
leapfrog.py   — Pure function: apply_leapfrog(target, current) -> adjusted
                Predictive overshoot to compensate for mechanical motor lag.
antenna.py    — TravlerAntenna: high-level control wrapping protocol + leapfrog
                This is what consumers (CLI, rotctld, future MCP server) call.
rotctld.py    — RotctldServer: Hamlib rotctld TCP protocol (p/P/S/_/q)
                Bridges Gpredict to the antenna.
cli.py        — Click CLI with init/serve/pos/move subcommands

Firmware Variants

Five known Winegard dish variants documented by Gabe Emerson (KL1FI) / saveitforparts and cdavidson0522:

Detail	HAL 0.0.00	HAL 2.05.003	Trav'ler Pro	Carryout	Carryout G2
Repo	Travler_Rotor	Trav-ler-Rotor-For-HAL-2.05	Travler-Pro-Rotor	Carryout-Rotor	winegard-sky-scan
Connection	RS-485 / RJ-25	RS-485 / RJ-25	USB A-to-A (ttyACM0)	RS-485 / RJ-25	RS-422 / RJ-12 6P6C
Baud rate	57600	57600	57600	57600	115200
Motor submenu	mot	motor	odu then mot	N/A (target + g)	mot
Motor control	a <id> <deg>	a <id> <deg>	a <id> <deg>	g <az> <el> only	a <id> <deg>
Search kill	os -> kill Search	ngsearch -> s -> q	os -> kill Search	N/A	NVS 20 (permanent disable)
Boot signal	NoGPS	NoGPS or No LNB Voltage	undocumented	N/A	Boot Complete then Loc Startup: IDU NOT Present
Min elevation	15 deg (firmware)	15 deg (firmware)	12 deg (firmware)	22 deg (firmware-enforced)	18 deg (firmware)
Max elevation	90 deg	90 deg	75 deg (hardware cap!)	73 deg (firmware default, NVS 102 override)	65 deg (firmware)
Position query	a -> AZ = / EL =	a -> AZ = / EL =	a -> AZ = / EL =	raw ints / 100	a -> floats
Tested model	LG-2112	LG-2112	SK2DISH	2003 Carryout	Carryout G2
HAL version	0.0.00	2.05.003	unknown	1.00.065	02.02.48
Prompt char	> (likely)	> (likely)	undocumented	undocumented	TRK> / MOT> / NVS> (confirmed)
Position format	AZ = / EL =	AZ = / EL =	AZ = / EL =	raw ints / 100	Angle[0] = / Angle[1] =
DVB tuner	unknown	unknown	unknown	unknown	BCM4515 (Broadcom)

Key Variant Differences

• Trav'ler Pro odu command: The Pro's IDU has its own MCU. You must first tunnel to the ODU with odu before entering the motor submenu. The regular Trav'ler's IDU is a dumb RS-485 passthrough.
• Carryout uses g not a: The Carryout has no individual motor addressing. It uses target to enter targeting mode, then g <az> <el> for combined moves. It also can't query its initial position.
• Carryout has no limit switches: Uses motor stalling to detect mechanical boundaries (audible grinding).
• Pro has the same leap-frog bug as the regular Trav'ler (copy-pasted).
• NVS d command dumps all NVS values. Confirmed on Pro and Carryout G2; likely available on all variants.
• Carryout DIP switches: All switches to off (up) may disable search mode, but behavior varies by unit.
• Carryout G2 uses a not g: Unlike the 2003 Carryout, the G2 uses standard a <id> <deg> motor addressing and the mot submenu — protocol-compatible with the Trav'ler family.
• Carryout G2 is RS-422 full-duplex: Separate TX/RX pairs at 115200 baud via RJ-12 6P6C, vs. RS-485 half-duplex at 57600 on the Trav'ler variants. Tested with DSD TECH SH-U11 USB-to-RS422 adapter (FTDI FT232R). Polarity matters — A/B (or +/-) labeling is not standardized; if you get garbled data at the correct baud rate, swap the +/- wires on the RX pair. TX pair polarity swap causes the dish to not receive commands (silent failure).
• Carryout G2 position format differs from Trav'ler: Position query a in MOT> submenu returns Angle[0] = 180.00 / Angle[1] = 45.00 — not the AZ = / EL = format used by HAL 0.0.00 and HAL 2.05. The CarryoutG2Protocol parser needs to handle this format.
• Carryout G2 firmware version 02.02.48 confirmed (Copyright 2013 - Winegard Company). Bootloader version 1.01. MCU: Kinetis (NXP ARM Cortex-M). DVB tuner: BCM4515 (Broadcom).
• Carryout G2 boot sequence: Bootloader → SPI init → Motor init (System=12Inch, master=40000 steps, slave=24960 steps, ratio=1.602564) → DVB tuner init (BCM4515) → NVS load → EL home (stall detect, 2s timeout) → AZ home (stall detect, 8s timeout) → Antenna Facing Front → TRK> prompt (if tracker disabled) or search start.
• Carryout G2 cable wrap: Confirmed from homing output: wrap_min:-42333 wrap_max:2333 (centidegrees). Total range ~446.66°.
• Carryout G2 has h <id> homing: Explicit motor home-to-reference command. Not documented on other variants.
• Carryout G2 has DVB/RSSI: Signal strength measurement via dvb submenu (lnbdc odu to enable LNA, rssi <n> to sample). Used for sky scanning / RF imaging. Atmospheric baseline measured at boot: ~494 (18V) / ~499 (13V) wideband.

Hardware Specs (SK-1000)

Spec	Value
Weight	45 lbs
Stow dimensions	10"H x 42"L x 26"W
Stow height	9.75"
Max deployed height	37" above mount
Arm reach	32.5" from base center
Dish size	~33" x 23" (Ku-band reflector)
Azimuth range	0-455 deg (before cable wrap)
Power input	120VAC -> 12VDC (RP-SK87 supply)
LNB bias	12-18VDC via coax
Motor type	Likely stepper with gearing (unconfirmed)
Satellites (DISH)	110, 119, 129 (61.5 manual only)
Satellites (Bell)	82, 91

Hardware Protocol Notes

• RS-485 serial, 57600 baud, 8N1 (via USB-to-RS232 + DTECH RS232-to-RS485 + RJ-25)
• Motor commands: a <motor_id> <degrees> (0=azimuth, 1=elevation)
• Position query: a (in motor submenu) returns AZ = <val> EL = <val> SK = <val>
• Two motor control methods:
  • a <id> <deg> — queues command, waits for current motor to finish. Tolerant of rapid command streams from Gpredict.
  • g <az> <el> <sk> — immediate move, aborts on any new keystroke/character. Some firmware has a typo listing the order as az/sk/el.
• Skew motor can run simultaneously with AZ or EL (the others are mutually exclusive)
• Elevation floor: HAL 2.05 unreliable below 15 degrees with direct motor commands
• Cable wrap limit: usually 360 or 455 degrees, dish reverses at limit
• Console does not accept backspace — hit enter to clear on typo
• Firmware prompt character is > (ASCII 62) — used for reliable response termination in prompt-terminated read strategies

RS-485 vs RS-422 — Serial Bus Differences

The Winegard variants use two different differential signaling standards. Understanding which one matters for choosing the right USB adapter.

RS-485 half-duplex (2-wire): One shared differential pair carries both TX and RX. Only one device talks at a time — the transmitter drives the bus, then releases it so the other side can respond. This is how the Trav'ler IDU communicates with the ODU: the IDU sends a command on the shared T/R pair, then listens for the response on the same wires. Simple wiring (2 signal wires + ground), but throughput is limited by the turn-around time between send and receive.

RS-422 full-duplex (4-wire): Two separate differential pairs — one dedicated TX pair and one dedicated RX pair. Both sides can transmit simultaneously because the signals don't share wires. Higher throughput (no bus turnaround penalty), and the Carryout G2 uses this at 115200 baud. Point-to-point only (one transmitter per pair).

RS-485 full-duplex (4-wire): Electrically identical to RS-422 wiring (same 4-wire differential pairs), but the RS-485 spec allows multiple transmitters on each pair (multi-drop bus). For our point-to-point dish↔computer connection, 4-wire RS-485 and RS-422 are interchangeable.

Property	RS-485 half-duplex	RS-422 / RS-485 full-duplex
Signal wires	2 (+ GND)	4 (+ GND)
Direction	One direction at a time	Both directions simultaneously
Max nodes	32 drivers + 32 receivers	1 driver + 10 receivers (RS-422)
Max distance	1200m / 4000ft	1200m / 4000ft
Max baud	~10 Mbps	~10 Mbps
Voltage swing	±1.5V to ±5V differential	±2V to ±5V differential
Bus turnaround	Required (adds latency)	Not needed
Typical adapter	USB-to-RS485 (DTECH, etc.)	USB-to-RS422 (FTDI, DIYables, etc.)

Practical consequence for this project: The Trav'ler's RJ-25 connector exposes both a half-duplex pair (pins 2-3, labeled T/R) and a dedicated receive pair (pins 4-5, labeled RXD). Gabe's code uses only the half-duplex pair via an RS-485 adapter. Davidson's G2 code uses all four wires as RS-422. The same physical connector may support both modes depending on the firmware — this is unconfirmed on the Trav'ler but worth testing if you have a 4-wire adapter available.

Serial Connector Pinout

The physical connector is an RJ-25 (6P6C) on the Trav'ler or RJ-12 (6P6C) on the G2 — same form factor, same 6-pin modular jack.

Trav'ler pinout (RJ-25, bottom view, clip up):

Pin	Label	RS-485 use	RS-422 use
1	GND	Ground	Ground
2	T/R-	Shared data-	TX- (computer→dish)
3	T/R+	Shared data+	TX+ (computer→dish)
4	RXD-	(unused in half-duplex)	RX- (dish→computer)
5	RXD+	(unused in half-duplex)	RX+ (dish→computer)
6	N/C	Not connected	Not connected

Carryout G2 pinout (RJ-12, clip away, per Davidson's wiring guide):

Pin	Wire Color (Davidson)	Wire Color (confirmed)	RS-422 Function
1	White	Orange/White	GND (PE)
2	Red	Orange	TX+ (TA) — computer→dish
3	Black	Green/White	TX- (TB) — computer→dish
4	Yellow	Blue	RX+ (RA) — dish→computer
5	Green	Blue/White	RX- (RB) — dish→computer
6	Blue	Green	Not connected

Note: Wire colors vary by cable manufacturer. The "confirmed" column is from a standard 6P6C flat cable tested 2026-02-12. Always verify with a multimeter before connecting. Polarity is critical: swapping +/- on the RX pair produces garbled data at the correct baud rate (systematic bit inversion, not random noise). Swapping +/- on the TX pair causes silent failure (dish doesn't respond because it can't decode the inverted framing).

Adapter chain by variant:

Variant	Adapter	Wires Used
Trav'ler (Gabe's setup)	USB→RS232→RS485 (DTECH)	Pins 2-3 only (half-duplex)
Carryout G2 (Davidson)	USB→RS422 (5V TTL)	Pins 2-5 (full-duplex)
Carryout G2 (confirmed)	DSD TECH SH-U11 USB→RS422 (FTDI FT232R)	Pins 1-5 (full-duplex + GND)
Carryout G2 (ESP32)	ESP32 UART2→RS422 module (DIYables)	Pins 2-5 (full-duplex)

RS-422 Module Notes (DIYables MAX490)

The DIYables RS422-to-TTL module uses the MAX490 transceiver chip (2.5 Mbps max, well above our 115200 baud). Key specs:

• 5V TTL logic on the microcontroller side (RXD/TXD)
• 15 kV ESD protection on RS-422 lines
• TVS diode for lightning/spike suppression
• 10 ohm current-limiting resistors for overcurrent protection
• Built-in 120 ohm termination resistor (reduces echo on long runs)
• Power + TX/RX activity LEDs
• Board size: 5.0cm x 2.7cm

Failsafe concern: The MAX490 does not have failsafe logic, and the module has no provisions for passive failsafe bias resistors. When the RS-422 bus tri-states (no driver active — e.g., between commands, during power transitions, or if the dish firmware is slow to respond), the receiver inputs float and may see random transitions interpreted as garbage data. This can cause spurious bytes in the serial stream.

Workaround options:

1. Add external bias resistors — pull A/RX+ toward V+ and B/RX- toward GND through ~560 ohm resistors. This biases the idle bus to a known logic-high state (RS-422 "mark" / idle). Solder to the module or add inline on the RJ-12 breakout.
2. Use the prompt-terminated read strategy — our CarryoutG2Protocol._send() reads until > (ASCII 62) which naturally filters out garbage between commands, since random transitions are unlikely to produce a valid > in context.
3. Ignore idle noise in firmware — the Winegard firmware likely ignores unexpected input while it's processing or idle, but any bytes received during the bus float could corrupt the next valid command if they land in the UART buffer at the wrong time.

For short cable runs (under ~3m between ESP32 and dish), the built-in 120 ohm termination is sufficient and bus float is less likely to cause issues. For longer runs or electrically noisy environments (near motors, power supplies), add the bias resistors.

Firmware Console Commands

?              — list available commands
motor / mot    — enter motor submenu (firmware-dependent)
a              — show position (in motor submenu)
a <id> <deg>   — move motor to absolute position
h <id>         — home motor to reference position (G2, possibly others)
g <az> <el>    — go to AZ/EL (aborts on new input)
q              — exit current submenu
odu            — tunnel to outdoor unit (Trav'ler Pro only)
os             — enter OS submenu
  tasks        — list running tasks
  kill <name>  — kill a named task (e.g. "kill Search")
ngsearch       — enter search submenu (HAL 2.05 only)
  s            — stop search
nvs            — enter non-volatile storage submenu
  d            — dump all values (confirmed on Pro and G2)
  d <idx>      — dump single value with name/current/saved/default
  e <idx>      — read NVS value
  e <idx> <v>  — write NVS value
  s            — save changes
dvb            — signal info / LNB signal strength submenu
  lnbdc odu    — enable LNA in ODU mode (powers LNB for reception)
  rssi <n>     — read RSSI signal strength averaged over n samples
reboot         — reboot firmware
stow           — fold dish flat (caution: modified feeds may not survive)

Known NVS Indices

Full dump in docs/g2-nvs-dump.md (firmware 02.02.48, captured 2026-02-12).

Index	Setting	Default	Notes
20	Disable Tracker Proc?	FALSE	Set TRUE to prevent TV satellite search on boot
38	Sleep Mode Timer Secs	420	7 minutes before sleep
41	Satellite Scan Velocity	55.00	°/s during TV search
80	AZ Max Vel	65.00	°/s azimuth max velocity
81	AZ Max Accel	400.00	°/s² azimuth max acceleration
83	AZ Steps/Rev	40000	Stepper steps per full rotation
85	EL Max Vel	45.00	°/s elevation max velocity
88	EL Steps/Rev	24960	Stepper steps per full EL rotation
101	Minimum Elevation Angle	18.00	Firmware floor (degrees)
102	Maximum Elevation Angle	65.00	Firmware ceiling (degrees)
103	Elevation Home Angle	65.00	EL position after homing
112	Disable Dipswitch?	FALSE	Override physical DIP switches
113	Dipswitch Value	101	DirecTV config (ignored when tracker disabled)
128-133	AZ/EL PID Gains	varies	Kp/Kv/Ki tuning parameters

Error Messages

Message	Meaning
AZ MOTOR STALLED	Obstruction preventing rotation
EL MOTOR STALLED	Obstruction preventing elevation change
EL Motor Home Failure	Requires EL recalibration via IDU menu

IDU/ODU Cable Wiring (if cut)

Top row: Green, Yellow, Orange. Bottom row: Red, Brown, Black.

Power

120VAC input to RP-SK87 power supply, outputs 12VDC to IDU. Internal coax carries 12-18VDC bias for LNB — do not connect 5V equipment (SDR LNAs, etc.) without bypassing the power injector.

Physical Setup

• Base marked with arrows and "BACK" at 0/360 deg (North)
• Align "BACK" with true North for accurate tracking
• Gpredict rotor config: 127.0.0.1:4533, 0->180->360 mode, min EL 15, max EL 90
• No obstructions taller than 8" within 32.5" of base center

Calibration

On power-up, the dish performs calibration movements to establish position and cable wrap limits (~10-15 minutes on Carryout, shorter on Trav'ler). After calibration, firmware automatically starts a TV satellite search — the init sequence kills this.

Carryout uses motor stalling (not limit switches) to detect mechanical boundaries — expect audible grinding during calibration.

EL recalibration (via IDU buttons): POWER -> ENTER (hold 2s) -> User Menu -> INSTALLATION -> Calibrate EL -> confirm hard stop position.

Emergency Manual Stow

Last resort only. 5/16" socket + 6" extension into auxiliary drive hole. Turn clockwise slowly. Ensure arm faces "rear" label before lowering. Improper execution can damage motor.

Known Bugs (from upstream)

• Leap-frog elevation bug: original travler_rotor.py lines 98-105 modify target_az instead of target_el. Fixed in leapfrog.py. Present in both Trav'ler and Trav'ler Pro repos. See docs/bugs.md.

Upstream References

• github.com/saveitforparts/Travler_Rotor (HAL 0.0.00)
• github.com/saveitforparts/Trav-ler-Rotor-For-HAL-2.05 (HAL 2.05)
• github.com/saveitforparts/Travler-Pro-Rotor (Pro, USB)
• github.com/saveitforparts/Carryout-Rotor (Carryout, HAL 1.00.065)
• github.com/saveitforparts/Carryout-Radio-Telescope (RF scanning/imaging)
• github.com/cdavidson0522/winegard-sky-scan (Carryout G2 sky scan + rotator)
• Gabe Emerson / KL1FI — gabe@saveitforparts.com
• YouTube: Trav'ler v1 demo (youtu.be/X1hnReHepFI), v2 demo (youtube.com/watch?v=URJZjo5EcpQ)

Testing

No hardware-in-the-loop tests yet. Protocol implementations can be mocked for unit testing — FirmwareProtocol is an ABC with clear method contracts.