OSS-RTK – Open Survey System RTK

Configuration Structure — Web UI

This document describes the configuration structure of the RTCM LoRa Transmitter device as exposed through the Web UI. It serves as input for the work on redesigning the interface in Figma.

The interface is divided into 5 tabs:

#	Tab ID	Label	Description
1	`wifi`	WiFi	WiFi connection configuration
2	`ntrip`	NTRIP	NTRIP caster configuration
3	`gga`	GGA Position	Base station position (GGA)
4	`lora`	LoRa Radio	LoRa radio parameters (SX1276)
5	`rtcm`	RTCM Filtering	RTCM message type filtering

Global actions (outside the tabs)

Action	Type	Behavior
Save & Restart	Submit (primary)	Validation → confirm dialog → POST config → device restart
Reload Config	Button (secondary)	Fetches the current configuration from the device
Restart Device	Button (danger)	Confirm dialog → device restart

Configuration sections — field details

1. WiFi

Field	JSON Key	Type	Required	Validation	Default value	Notes
WiFi Network (SSID)	`wifi.ssid`	`string`	✅	Non-empty	`""`	Has a “Scan” action — opens a modal with a list of available networks
Password	`wifi.password`	`string` (password)	❌	—	`""`	Empty = open network
Connection Timeout	`wifi.timeout`	`integer` (ms)	✅	min: 5000, max: 60000, step: 1000	`30000`

Additional functionality: WiFi scan modal

Displays a list of networks sorted by RSSI (signal strength)
Each network shows: SSID, BSSID, channel, RSSI (dBm), encryption type (open/secured), signal strength icon
Clicking a network inserts the SSID into the form field
The Rescan button allows re-running the scan

2. NTRIP

Field	JSON Key	Type	Required	Validation	Default value	Notes
Host	`ntrip.host`	`string`	✅	Non-empty	`"91.198.76.2"`
Port	`ntrip.port`	`integer`	✅	min: 1, max: 65535	`2101`
Username	`ntrip.user`	`string`	❌	—	`""`
Password	`ntrip.password`	`string` (password)	❌	—	`""`
Mountpoint	`ntrip.mountpoint`	`string`	✅	Non-empty	`"RTN4G_VRS_RTCM32"`	Has a “Fetch” action — opens a modal with a list of mountpoints
Connection Timeout	`ntrip.timeout`	`integer` (ms)	✅	min: 5000, max: 60000, step: 1000	`10000`

Additional functionality: NTRIP mountpoint fetch modal

Requires the Host and Port fields to be filled in first (validation before opening)
Sends a request to the NTRIP caster with the provided credentials
Displays a list of mountpoint names
Clicking a mountpoint inserts its name into the form field
The Refresh button allows re-running the fetch

3. GGA Position

Field	JSON Key	Type	Required	Validation	Default value	Notes
Latitude (°)	`gga.latitude`	`float`	✅	min: -90, max: 90, step: 0.0001	`50.2346`	Decimal degrees, positive = North
Longitude (°)	`gga.longitude`	`float`	✅	min: -180, max: 180, step: 0.0001	`19.2084`	Decimal degrees
Altitude (m)	`gga.altitude`	`float`	✅	step: 0.1	`266.0`	Meters above sea level
Send Interval (ms)	`gga.sendInterval`	`integer` (ms)	✅	min: 1000, max: 60000, step: 1000	`2000`	Interval for sending GGA to the NTRIP caster

4. LoRa Radio

Field	JSON Key	Type	Required	Validation	Default value	Notes
Frequency (MHz)	`lora.frequency`	`integer` (Hz in API)	✅	min: 137 MHz, max: 1020 MHz	`433000000` (433 MHz)	UI displays MHz, API stores Hz
Spreading Factor	`lora.spreadingFactor`	`integer` (enum)	✅	6–12	`7`	Select: SF6, SF7, SF8, SF9, SF10, SF11, SF12
Bandwidth (Hz)	`lora.bandwidth`	`integer` (enum)	✅	Values from the list	`125000`	Select — see table below
Coding Rate	`lora.codingRate`	`integer` (enum)	✅	5–8	`5`	Select: 4/5, 4/6, 4/7, 4/8
TX Power (dBm)	`lora.txPower`	`integer`	✅	min: 2, max: 20	`20`
Sync Word (hex)	`lora.syncWord`	`integer` (hex)	✅	Format: `0x[0-9A-Fa-f]{2}`	`0x12`	UI displays hex (e.g. `0x12`), API stores an integer

Allowed Bandwidth values:

Value (Hz)	UI Label
7800	7.8 kHz
10400	10.4 kHz
15600	15.6 kHz
20800	20.8 kHz
31250	31.25 kHz
41700	41.7 kHz
62500	62.5 kHz
125000	125 kHz
250000	250 kHz
500000	500 kHz

5. RTCM Filtering

Field	JSON Key	Type	Required	Validation	Default value	Notes
Allowed Message Types	`rtcm.messageTypes`	`array<integer>`	✅	Min 1 element	`[1005, 1007, 1019, 1020, 1033, 1075, 1085, 1095, 1125, 1230]`	UI: textarea, comma-separated
High Priority Types	`rtcm.priorityMessageTypes`	`array<integer>`	❌	—	`[1005, 1075, 1085, 1095, 1125, 1230]`	UI: textarea, comma-separated; Types transmitted with higher priority

API Contract

All endpoints are available over HTTP on port 80 (Access Point).

`GET /api/config` — Fetch configuration

Response 200 OK — application/json

{
  "wifi": {
    "ssid": "string",
    "password": "string",
    "timeout": 30000
  },
  "ntrip": {
    "host": "string",
    "port": 2101,
    "mountpoint": "string",
    "user": "string",
    "password": "string",
    "timeout": 10000
  },
  "gga": {
    "latitude": 50.2346,
    "longitude": 19.2084,
    "altitude": 266.0,
    "sendInterval": 2000
  },
  "lora": {
    "frequency": 433000000,
    "spreadingFactor": 7,
    "bandwidth": 125000,
    "codingRate": 5,
    "txPower": 20,
    "syncWord": 18
  },
  "rtcm": {
    "messageTypes": [
      1005, 1007, 1019, 1020, 1033, 1075, 1085, 1095, 1125, 1230
    ],
    "priorityMessageTypes": [1005, 1075, 1085, 1095, 1125, 1230]
  },
  "display": {
    "updateInterval": 500
  }
}

Note: The display section is present in the API but is not exposed in the current UI.

`POST /api/config` — Save configuration

Request — Content-Type: application/json

Body: the same structure as the response from GET /api/config. All sections are optional — the sections sent overwrite the existing configuration, while omitted sections remain unchanged.

Response 200 OK:

{ "success": true, "message": "Configuration saved. Device will restart." }

Response 400 Bad Request:

{ "success": false, "message": "Invalid JSON" }

{ "success": false, "message": "No data received" }

Response 500 Internal Server Error:

{ "success": false, "message": "Failed to save configuration" }

Behavior: After a successful save, the device automatically restarts after ~1s.

`POST /api/restart` — Restart the device

Request: Empty body.

Response 200 OK:

{ "success": true, "message": "Device restarting..." }

`POST /api/wifi/scan` — Scan WiFi networks

Request: Empty body.

Response 200 OK:

{
  "success": true,
  "networks": [
    {
      "ssid": "MyNetwork",
      "bssid": "AA:BB:CC:DD:EE:FF",
      "rssi": -45,
      "encryption": "secured",
      "channel": 6
    }
  ]
}

Field	Type	Description
`ssid`	`string`	Network name
`bssid`	`string`	Access point MAC address (format: `XX:XX:XX:XX:XX:XX`)
`rssi`	`integer`	Signal strength in dBm (higher = better)
`encryption`	`string`	`"open"` or `"secured"`
`channel`	`integer`	WiFi channel

Response 500:

{ "success": false, "message": "Scan failed" }

`POST /api/ntrip/mountpoints` — Fetch NTRIP mountpoints

Request — Content-Type: application/x-www-form-urlencoded

Parameter	Required	Description
`host`	✅	NTRIP caster host address
`port`	✅	Caster port
`user`	❌	Login (if required)
`password`	❌	Password (if required)

Response 200 OK:

{
  "mountpoints": ["RTN4G_VRS_RTCM32", "NEAREST_RTN", "VRS_3_2"]
}

Response 200 OK (error):

{ "error": "Connection failed" }

Response 400 Bad Request:

{ "error": "Missing host or port parameter" }

Validation (UI-side)

Validation happens before the form is submitted. List of rules:

Rule	Error message
`wifi.ssid` is empty	“WiFi SSID is required”
`ntrip.host` is empty	“NTRIP host is required”
`ntrip.port` < 1 or > 65535	“NTRIP port must be between 1 and 65535”
`gga.latitude` < -90 or > 90	“Latitude must be between -90 and 90”
`gga.longitude` < -180 or > 180	“Longitude must be between -180 and 180”
`lora.frequency` < 137 MHz or > 1020 MHz	“LoRa frequency out of valid range (137–1020 MHz)”
`lora.spreadingFactor` < 6 or > 12	“Spreading factor must be between 6 and 12”
`lora.txPower` < 2 or > 20	“TX power must be between 2 and 20 dBm”
`rtcm.messageTypes` is empty	“At least one RTCM message type must be configured”

Note: Validation exists only on the UI side. The backend does not validate values — it accepts whatever it receives in valid JSON.

Data conversions (UI ↔ API)

Field	UI format	API format	Conversion
`lora.frequency`	MHz (e.g. `433.085`)	Hz (e.g. `433085000`)	UI→API: `× 1e6`, API→UI: `÷ 1e6`
`lora.syncWord`	Hex string (e.g. `0x12`)	Integer (e.g. `18`)	UI→API: `parseInt(val, 16)`, API→UI: `"0x" + val.toString(16)`
`rtcm.messageTypes`	Comma-separated string (e.g. `"1005, 1075"`)	Array of integers (e.g. `[1005, 1075]`)	UI→API: split + parseInt, API→UI: join
`rtcm.priorityMessageTypes`	Comma-separated string	Array of integers	same as above

Network and Access Point

The device starts an Access Point named OSS-LoRa-TX-XXXX (where XXXX = the last 4 characters of the MAC)
The AP has no password (open network)
AP timeout: 3 minutes without a client → the AP shuts down
After a client connects and then disconnects: 3 minutes → the AP shuts down
The Web UI is available at http://192.168.4.1/

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OSS-RTK – Open Survey System RTK

Configuration Structure — Web UI

UI Navigation

Global actions (outside the tabs)

Configuration sections — field details

1. WiFi

2. NTRIP

3. GGA Position

4. LoRa Radio

5. RTCM Filtering

API Contract

GET /api/config — Fetch configuration

POST /api/config — Save configuration

POST /api/restart — Restart the device

POST /api/wifi/scan — Scan WiFi networks

POST /api/ntrip/mountpoints — Fetch NTRIP mountpoints

Validation (UI-side)

Data conversions (UI ↔ API)

Network and Access Point

`GET /api/config` — Fetch configuration

`POST /api/config` — Save configuration

`POST /api/restart` — Restart the device

`POST /api/wifi/scan` — Scan WiFi networks

`POST /api/ntrip/mountpoints` — Fetch NTRIP mountpoints