Designed and manufactured in Boulder, Colorado, USA, the SparkFun RTK Facet is your one-stop shop for high precision geolocation and surveying needs. For basic users, it’s incredibly easy to get up and running; for advanced users, the RTK Facet is a flexible and powerful tool, with full calibration by the NGS. With just a few minutes of setup, the RTK Facet is one of the fastest ways to take centimeter-grade measurements. By connecting your phone to the RTK Facet over Bluetooth®, your phone can act as the radio link to provide correction data as well as receive the NMEA output from the device. This is exactly how $10,000 surveying devices have been operating for the past decade - we just made it easier, smaller, and a lot more economical.
The RTK Facet works with common GIS software for Android and iOS including SW Maps Android / iOS, Field Genius, SurvPC, Survey Master, Vespucci, QGIS, QField, and any GIS software that supports NMEA over Bluetooth.
Under the hood of the SparkFun RTK Facet is an ESP32 WROOM connected to a ZED-F9P as well as some peripheral hardware (LiPo fuel gauge, microSD, etc). Additionally, housed under the dome of the RTK Facet is a surveyor grade L1/L2 antenna. It is the same element found within our GNSS Multi-Band L1/L2 Surveying Antenna. The built-in antenna has an ARP of 61.4mm from the base to the measuring point of the L1 antenna and an ARP of 57.4mm to the measuring point of the L2 antenna. The RTK Facet is programmed in Arduino and can be tailored by you to fit whatever your needs may be.
This device can be used in four modes:
At Power On the device will enter Rover or Base mode; whichever state the device was in at the last power down. When the POWER/SETUP button is pressed momentarily, a menu is presented to change the RTK Facet to Rover or Base mode. The display will indicate the change with a small car or flag icon.
In Rover mode the RTK Facet will receive L1 and L2 GNSS signals from the four constellations (GPS, GLONASS, Galileo, and BeiDou) and calculate the position based on these signals. Similar to a standard grade GPS receiver, the RTK Facet will output industry standard NMEA sentences at 4Hz and broadcast them over any paired Bluetooth® device. The end user will need to parse the NMEA sentences using commonly available mobile apps, GIS products, or embedded devices (there are many open source libraries). Unlike standard grade GPS receivers that have 2500mm accuracy, the accuracy in this mode is approximately 300mm horizontal positional accuracy.
When the device is in Rover mode and RTCM correction data is sent over Bluetooth® or into the radio port, the device will automatically enter Positioning with RTK mode. In this mode RTK Facet will receive L1/L2 signals from the antenna and correction data from a base station. The receiver will quickly (within a second) obtain RTK float, then fix. The NMEA sentences will have increased accuracy of 14mm horizontal and 10mm vertical accuracy. The RTCM correction data is most easily obtained over the Internet using a free app on your phone (see SW Maps or Lefebure NTRIP) and sent over Bluetooth® to the RTK Facet but RTCM can also be delivered over an external cellular or radio link to a 2nd RTK Facet setup as a base station.
In Base mode the device will enter Base Station mode. This is used when the device is mounted to a fixed position (like a tripod or roof). The RTK Facet will initiate a survey. After 60 to 120 seconds the survey will complete and the RTK Facet will begin transmitting RTCM correction data out the radio port. A base is often used in conjunction with a second RTK Facet (or RTK Surveyor, Express, etc) unit set to 'Rover' to obtain the 14mm accuracy. Said differently, the Base sits still and sends correction data to the Rover so that the Rover can output a really accurate position. You’ll create an RTK system without any other setup.
In addition to supplying position data the RTK Facet is capable of logging NMEA, RAWX, and SFRBX for post processing making it ideal for research and advanced positioning applications.
The RTK Facet is an open source hardware product meaning you can fully obtain, see, and even modify the electrical and mechanical design files. This allows for easier maintenance and repair over time.
Note: The SparkFun RTK Facet is just the enclosed device with thread adapter, charger, data cables, and carrying case. It does NOT include serial telemetry radio or associated mounting poles. These items will need to be purchased separately.
Supported GIS Data Collector Software:
GNSS Receiver: ZED-F9P
Bluetooth® Transceiver: ESP32 WROOM
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Based on 14 ratings:
2 of 2 found this helpful:
We bought a couple gnss, base and rover, we had used trimble, sokkia and emlid Gnss, and this is a good begining for surveyors, maybe sparkfun can develop a simple software like emlid flow for a most simply interface, and more capabilitys for take point for postprocessing. Good Job.
3 of 3 found this helpful:
10/28 Update- No detectable activity or response from tech support.
I was very excited to receive the unit. My use case is that I'm building a house in a rural area and wanted to collect data points to generate a high resolution topo map and precisely map power and water lines, sprinkler boxes, etc..
The unit would not charge right out of the box. It powered on fine, and would communicate with my laptop fine. The charger worked with other devices, and other good charging block/cables did not work on the Facet. So- RMA (shipped at my expense). Sparkfun tech support has shown little motivation to understand/fix the problem and get the unit back to me. Tech support has been polite and matter-of-fact through email (they don't provide ANY phone support). After receiving it on 10/13, I was told yesterday (10/21) that someone would look at it on 10/25. POOR!
I used the unit until the battery died and it did what I expect and needed for the time it worked. I'm sure I would have posted a pretty positive review if not for this out-of-the-box quality issue and the poor R&R experience.
1 of 1 found this helpful:
The RTK Facet is a really useful tool and I've been using it with SWMaps to perform many tasks around the farm. Field and fence layouts, locations for lines etc... It's a really awesome tool and accuracy was confirmed in horizontal and vertical using a local monument with precise H and V coordinates. Thanks Sparkfun for an awesome kit. For some reason it won't let me leave 5 stars. It deserves all 5 though.
2 of 2 found this helpful:
Great work sparkfun on putting together a unit that competes with some of the best GNSS receivers in the market from Trimble, Leica, Sokkia, etc.
The possibility of tuning this device to cater to your needs is another huge advantage that I've found very useful. F9P chip is next level. I've been enjoying 14mm accuracy on my projects and aiming to tune that down to 6mm with some least squares adjustment!
Great work sparkfunners!
1 of 1 found this helpful:
I've only used it a little so far but overall impressed. Compares very favorably to traditional survey units, amazing for the price. Only real issue is that you are still at the mercy of expensive correction services if you want to use it as a rover with NTRIP rather than buying 2 and running Base+Rover.
Excelente capacidade de conexão muito acima das grandes marcas do mercado. É uma excelente solução. Produto muito bem concebido. Parabéns Sparkfun.
I have been operating this device using Landstar 7 software and utilizing a local CORS station and I've been getting Fix solutions and rarely Float Solutions. However my Landstar 7 Subscription expired and now using Field genius for Android. Unfortunately, I'm getting DGPS solution in FGA.
El Equipo Facet RTK con su receptor Ublox ZED F9P es muy preciso aún sin correcciones en tiempo real Ntrip. Me llega a dar mediciones de 4-5 centímetros con RTK float. De latencia de punto base en otros países al pesar que en Honduras no está activa estaciones CORS Ntrip. Con cliente caster rtk2go.com me alcanza para tomar puntos de 4/5 cm. De error en cielo despejado. Aspirando tener Rtk fix en un momento de llegada de correcciones Ntrip en Honduras. Por ahora toca hacer Postproceso a falta de otro equipo base SparkFun. Mis 5 🤩 estrellas para este fabuloso equipo.
Seven months ago I knew nothing about GNSS, I started using my first Facet about 6 months ago, since then I bought an RTK drone and a second Facet. I'm using one as a base and the other Facet as a rover, marking GCPs. I also took a course in orthomosaic mapping. I use the base and rover with an Ntrip caster and a pair of LoRa radios, the base casts to the rover for the GCP survey, and then it casts to the drone for RTK corrections, producing a staggering level of accuracy. The firmware is getting better all the time, with many features making it the rival of units costing many times the price of the SparkFun Facet. I'm hooked!
I am using this for precision surveying needs for my land/home build needs. I have a background using Trimble and Topcon systems in profession work and have loved SparkFun for all my sensor and chip project needs. Purchased two units, one for base and another as my rover. Using two plug and play 100mW 915 Mhz Telemetries, tested via PC to PC com first and then plugged in. Instant correction data sent, love the ease there.
Edit: after some tinkering I was able to store and retrieve the BaseConfiguration file. I was even able to download and configure all my control points via PC and then migrating back to SD card. Pretty easy setup now!
I had four control points surveyed in on my property and then set up the base on a tripod with a tribrach. Using the WiFi RTK configuration, I was able to use the Fixed, Geodetic base configuration to zero in on my base control. I then shot the three other control points using SW Maps with the Rover and was getting incredible precision, about 10mm.
The WiFi RTK configuration works, though some features are lacking or not functioning correctly. One of those is not being able to properly 'Add' a Geodetic Fixed Base point and actually save that point for recall.
After plugging in an SD card and configuring my four control points with Northing, Easting and Elevation, then 'Adding', I was able to click the load button and change between. After powering off base and turning on again, the configurations I added were all removed. I was hoping 'Add' would allow for long term storage of Fixed configuration, not ideal having to add each time.