This spring I equipped my Fastrac 8310.
This tractor is Trimble ready, it had an Trimble IMU on the front left wheel and all the harness for the NAV controller and main screen.
A special feature on this tractor is that the steering wheel is mechanically linked to the wheels so the steering wheel will turn all time.
The OEM autosteer hydraulic block has a built-in safety: as soon as you take control of the steering wheel a bypass valve is activated, dumping the autosteer pressure. So even if Autosteer try to turn you can easily override it, you just feel a very little resistance in the steering wheel.
So instead the NAV I put an AiO, used the analog WAS signal from the 4WD/diff lock, the factory valve driven by a cytron and connected the CANBUS to use the original engage signal programmable on the tractor screen.
Fastrac_schema_autosteer.pdf (1,7 Mo)
The antenna ( cable enter on the top rear window and goes down inside the rear left pillar):
The Lock valve is controlled by the ECU, it must be diverted and a 8 ohm resistance put on the ECU side to avoid error code.
(I think the side (blue/black) on the picture are inverted on this picture)
Here the whole connector that goes behind the seat:
(The 3 pin connector is for the power
the yellow wire is WAS
black and white are for the ISO implement plug, for work switch)
Here the wire tapped in the analog WAS signal:
(I works but the signal change slightly when the work-lights are on.
I think it maybe would be better to use the 4 original wires from Trimble IMU going the the front axle to tap near in the sensor and feed it with AiO 5v. Adding a relay to switch 5v source when AiO is ON/OFF)
The harness installed:
(You can see the blue AOG ethernet cable going from left to the right side)
The harness, ethernet and GPS cable under the helper seat, ready for AIO
The AiO to NAV adapter:
My AiO(custom made):
The board ready to install
The tablet is powered on the right side trough the original GPS harness, AiO and charger are powered with ignition switch, there’s a switch to turn the system OFF if not used for a while.
The OEM streerswitch is used to cut power to the Cytron for aditional safety.
The OEM engage button is used, over CANBUS
The tablet, with 3Dprinted mount and 1.5in RAM mount.
The tablet, AOG and AgIO start automatically at ignition switch.
I also modified AOG to automatically make a clean shutdown of the tablet at power lose (ignition switch off)
I use a custom firmware, mainly because of the CANBUS engage (thanks @andyinv ), but also because I use RVC and the Teensy ADC(no ADS1115)
I also had to add 80 to the minimum PWM, for some reason this Trimble valve need 125 to move, at time AOG was limited to 100.
The whole ino is pretty experimental:
Autosteer_gps_teensy_RVC_fastrac.zip (33,3 Ko)
It worked well the whole spring!