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3 antennas would be enough, 2 on the cabin for the Roll (largest place to slip side by side) and one on the front center then you get a triangle.
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Front of tractor mounting isn’t possible for me as the tractor spend 70% of its time with a loader fitted…the arms get in the way!
So probably 1.5m spread is the best either direction.
This would be the ideal situation I think… Do all the processing on the computer / AOG, save having another external device with potential updates / changes etc, would also be easier to diagnose having each UBLOX connected directly to the PC…
Would also be nice to be able to pass through the correction information etc so that AgOpenGPS could display its fix info / RTK status etc…
Possibility to build these calcs into software with config page to setup how many antennas and location of said antennas / connection to PC Brian?
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It would be an option to connect both to AOG. The thing is, that the system with moving baseline and the UBX RelPosNED sentence is Ublox specific.
It works like this: #1 sends RTCM to #2, so connect #1 TX2 to #2 RX2.
#2 calculates the relative position to #1: heading, 3 vectors of direction, and length of vector to #1 this contains the RelPosNED sentence,that is Ublox specific.
#1 delivers position as every other GPS chip. When feeded with NRTIP it gives an absolute position, if not the normal GPS dissolution, whereas the heading and roll is allways correct, as it is relative from the 2 receivers.
So what the ESP32 does:
Feed one unit with NTRIP
Get position
Get relative vectors
Calculate roll (trigonometry)
Correct the antenna position by using roll and virtual Antenna movement (trigonometry)
Checks the sentences, the flags (GPS valid…), and the accuracy (length of vector to other antenna (suggested in Ublox manual))
Generate NMEA sentence (PAOGI (one for all) or GGA (position) + VTG (speed) + HDT (heading))
Transmit via UDP/ Wi-Fi or USB
It is doable in AOG, but you go back to USB. I like UDP since you can connect/ disconnected and Windows won’t care.
With the ESP32 solution it’s similar to a commercial solution, you get corrected data. Building is easy: the Ardusimple boards fit to Arduino uno layout, the esp too. Build a stack, connect to Arduino IDE, flash, configure in Webinterface- done. No IMU needed, maybe Wi-Fi router (with GSM for RTK) or connect ESP32 via USB
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a distance of 75cm will do, more is better see page 5 in UBlox reference:
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2 Antennas are enough, as pitch does not affect the direction.
I can certainly see reliability benefits of reducing number of USB / com connections to the PC…always potential for issues this way I guess… Does current version of AOG allow for GPS data incoming via UDP? Have got my autosteer PCB connected via UDP / makes sence to use this for as much as possible to simplify things…
I’ve actually never seen a dual antenna system in a tractor despite there being loads of autosteer tractors in my area.
Me neither come to think of it… But it does make sense to me / has got to be the best and fastest way to determine heading one would think…
It makes sense to me too but I’d be interested to see what difference it actually makes in field conditions. I’m assuming side draft has to be calculated out of the equation as L & R antennas would give a false heading.
I’m looking forward to getting my system out on real jobs rather than driving around in a bumpy maize field, to see just how accurate it is in work. Off topic but I’ve been impressed how well a correction signal 34Km away has worked up to now.
Yes, I currently have a test Setup on my desktop, that uses only UDP (GPS & steering).
RTCM/NTRIP from AOG over UDP to the PCB to the F9P, NMEA the other way.
I might be asking out of my depth here but is your F9P connected to Arduino D0 & D1?
If you mean me: connected to an ESP32.
Software: GitHub - doppelgrau/esp32-aog: Software to controll the tractor from AgOpenGPS
(Attention, documentation need to be fixed in some parts, IMU and dual GPS currently missing)
PCB: GitHub - doppelgrau/esp32-f9p-io-board: An IO-PCB (two motor-driver/H-bridge, CAN, RS232, ADS1115, relay, ethernet, ardusimple f9p compatible connector) with an ESP32 for 12V power, three 15V tolerant analog inputs, three 5V tolerant inputs.
(Software should run on other ESP32 setups too)
Any photos of your setup?
Yes and thank you. I’ll take a look.
The setup on my desk. PCB with the F9P fit into a 3d printed housing.
(PCB in front has no function other than holding the motor, potentiometer and LED - USB-cable only for programming/debugging connected.)
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It’s not about pitch, its about an accurate heading.