sl-controls
de9a835cc2
Adds saltybot_cellular ROS2 package for the Waveshare SIM7600X 4G HAT
(SIMCom SIM7600A-H) providing GPS telemetry, modem monitoring, and
MQTT relay over cellular for remote operation.
gps_driver_node:
- Opens /dev/ttyUSB2 (NMEA), optionally sends AT+CGPS=1 on /dev/ttyUSB0
- Parses GGA (position) + RMC (velocity) from any NMEA talker (GP/GN/GL/GA)
- Validates NMEA checksum before parsing
- Publishes /gps/fix (NavSatFix, covariance from HDOP × ±2.5m CEP)
- Publishes /gps/vel (TwistStamped, ENU vE/vN from course-over-ground)
- Publishes /diagnostics (fix quality, sat count, HDOP)
cellular_manager_node:
- Polls AT+CSQ, AT+CREG?, AT+COPS? every 5s over /dev/ttyUSB0
- Publishes /cellular/status (DiagnosticArray: rssi, network, connected)
- Publishes /cellular/rssi (Int32, dBm) and /cellular/connected (Bool)
- Auto-reconnect via nmcli or pppd when data link drops
mqtt_bridge_node:
- paho-mqtt client (graceful degradation if not installed)
- ROS2→MQTT QoS 0: /saltybot/imu, /gps/fix, /gps/vel, /uwb/ranges,
/person/target, /cellular/status
- MQTT→ROS2 QoS 1: saltybot/cmd→/saltybot/cmd, saltybot/estop→/saltybot/estop
- Per-topic rate limiting (imu:5Hz, gps:1Hz, person:2Hz) → <<50KB/s budget
- Optional TLS, configurable broker/port/prefix/auth
Deliverables:
saltybot_cellular/gps_driver_node.py — 402 lines
saltybot_cellular/cellular_manager_node.py — 362 lines
saltybot_cellular/mqtt_bridge_node.py — 317 lines
config/cellular_params.yaml — full config documented
launch/cellular.launch.py — all nodes, all params as args
test/test_cellular.py — 60 pytest tests, no ROS2
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
71 lines
3.7 KiB
YAML
71 lines
3.7 KiB
YAML
# cellular_params.yaml
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# Configuration for saltybot_cellular package — SIM7600X 4G HAT.
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#
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# Run with:
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# ros2 launch saltybot_cellular cellular.launch.py
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#
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# Hardware: Waveshare SIM7600X 4G HAT (SIMCom SIM7600A-H)
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# /dev/ttyUSB0 — AT commands
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# /dev/ttyUSB1 — PPP data (managed by NetworkManager/pppd, not ROS2)
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# /dev/ttyUSB2 — NMEA GPS output
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# ── GPS driver ─────────────────────────────────────────────────────────────────
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# The GPS port streams NMEA sentences once AT+CGPS=1 is sent.
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# If GPS is already running (e.g., from a previous session), set gps_init_enable: false.
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gps_port: /dev/ttyUSB2 # NMEA output port
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at_port: /dev/ttyUSB0 # AT command port (for CGPS=1 init)
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baud_rate: 115200
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publish_rate: 1.0 # Hz — GPS updates at 1 Hz max
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frame_id: gps # Header frame_id for NavSatFix + TwistStamped
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gps_init_enable: true # Send AT+CGPS=1 on startup
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gps_init_cmd: AT+CGPS=1 # Command to start GNSS receiver
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at_init_timeout: 3.0 # Seconds to wait for AT response
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# GPS accuracy (used for NavSatFix covariance computation)
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# SIM7600A-H spec: ±2.5m CEP (circular error probable) at HDOP=1
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gps_accuracy: 2.5 # metres CEP at HDOP=1
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# ── Cellular manager ───────────────────────────────────────────────────────────
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# AT commands are polled to monitor signal quality and registration status.
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# The data connection itself (4G LTE) is managed by the OS (NetworkManager or pppd).
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poll_rate: 0.2 # Hz (poll every 5 seconds — avoid AT flooding)
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at_timeout: 2.0 # Seconds per AT command
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# Data connection management
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# "nmcli": NetworkManager profile (recommended for Orin Nano running Ubuntu)
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# "pppd": pppd service unit (systemctl restart pppd-cellular)
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# "none": monitoring only, no auto-reconnect
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connection_method: nmcli
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nmcli_profile: saltybot-cellular # nmcli connection profile name
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apn: "" # APN (set if NetworkManager needs it)
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reconnect_interval: 30.0 # Seconds between reconnect attempts
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# ── MQTT bridge ────────────────────────────────────────────────────────────────
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# Relay telemetry to a remote MQTT broker over the cellular link.
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# For home-lab deployment: run mosquitto on the Jetson or a cloud VM.
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# For production: use TLS + authentication.
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mqtt_broker: mqtt.saltylab.local # Broker hostname or IP
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mqtt_port: 1883 # 1883 = plain, 8883 = TLS
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mqtt_user: "" # Leave empty to disable auth
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mqtt_password: ""
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topic_prefix: saltybot # MQTT topic prefix (saltybot/gps/fix, etc.)
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client_id: saltybot-jetson
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keepalive: 60 # MQTT keepalive interval (seconds)
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reconnect_delay: 5.0 # Seconds between MQTT reconnect attempts
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# TLS (set mqtt_port: 8883 and provide CA cert path)
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tls_enable: false
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tls_ca_cert: "" # e.g. /etc/ssl/certs/mqtt-ca.crt
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# Per-topic outbound rate limits (Hz). Keeps cellular bandwidth < 50 KB/s.
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# At 1 Hz per topic × ~100 bytes/msg × 6 topics ≈ 600 bytes/s = 0.6 KB/s
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imu_rate: 5.0 # Hz — /saltybot/imu → saltybot/imu
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gps_rate: 1.0 # Hz — /gps/fix, /gps/vel
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person_rate: 2.0 # Hz — /person/target
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uwb_rate: 1.0 # Hz — /uwb/ranges
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cellular_rate: 0.2 # Hz — /cellular/status (once per 5s)
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