Tractor gear change circuit

Thread Starter

tractorjames

Joined Feb 1, 2022
2
Hello, i dont know if this is the right place to be posting but im sure i will get told if not….

My tractors power shift gearbox has 4 clutchless gear changes and 4 manual gear changes. The clutchless changes are operated by solenoid valves on the side of the gearbox. The solenoids are controlled by a controller/ecu in the tractor cab which originally had a clumsy lever operated swich box to select the required gear. I have now fitted a gear lever with built in thumb scroll wheel for operating the clutchless changes.

A local electronics firm made me an interface that the new gear lever plugs into and then plugs into the tractors original controller. It translates the binary on off signal from the scroll wheel switch with 3 wires, into the signal that the original gear change lever worked with. The original set up has a 5v feed and earth and then 4 power supplies (one for each gear). Depending on the gear selected one of the 4 powers is pulled down with a load and the tractors controller powers up the relevant solenoid.

I now wish to make more of these interfaces for my other tractors but the chap that made my original one is too busy to do it. Is this something i can realistically make myself with no prior programming experience or is there anyone on here that would be interested in doing it for me?

Hope this isnt too long winded, tried to keep out of the detail of how the circuit works until i know if im posting in the right place but thought i best explain the back ground of the situation
Thanks
James
 
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Alec_t

Joined Sep 17, 2013
12,906
Welcome to AAC.
Sounds doable IF you know the signal format/protocol that the tractor's controller is expecting.
 

Thread Starter

tractorjames

Joined Feb 1, 2022
2
Welcome to AAC.
Sounds doable IF you know the signal format/protocol that the tractor's controller is expecting.
Hi , yes i have all that info. The frustrating thing is the chap that made the first one for me said it was nothing of a job and didn't charge me a lot of money its just he physically Doesnt have time to make me any more.
 

Alec_t

Joined Sep 17, 2013
12,906
Can you provide the scroll wheel spec and the signal protocol details?
Methinks a microcontroller was likely used in the interface. Someone here might be able to do the coding.
 

shortbus

Joined Sep 30, 2009
9,449
Hi , yes i have all that info. The frustrating thing is the chap that made the first one for me said it was nothing of a job and didn't charge me a lot of money its just he physically Doesnt have time to make me any more.
Will he share a schematic with you, of what he made?
 
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