Head module

Head module for the Keto 51 project will be located in the harvester head itself. The purpose of this module is to control the hydraulic valves and read the sensor inputs. It will be connected to the main control system using CAN bus. This way the wiring between the head and the base machine can be kept simple as only power and two wires for the CAN communication is needed instead of wiring all the valves and sensors all the way to the base machine.

Locating the electronic module to the head exposes it to quite challenging environment so there might be some additional problems to solve because of this. Vibration is probably the largest problem here.

The module will use AT90CAN128 microcontroller and also XC9572XL CPLD for the quadrature counters and output diagnostic monitoring.

Here is a photo of a partially assembled board. The board was designed and sent for manufacturing in the last minutes before leaving for vacation so it’s a bit of a mess in some ways and some problems have been found already. But it should work for prototyping.

Finding the right connector to interface the module to the outside world can be challenging too. For this first prototype a Molex Minifit Jr connector was chosen as it’s cheap and easy to get and should be quite easy to make changes compared to some other connectors out there.

But a better connector would be nice later. One alternative could be Econoseal from Tyco. This one is available in small quantity from the VEMS Shop. Another tempting connector is the Ampseal series which looks like it would be easier to make a sealed case with it. Just haven’t been able to find a place that would sell these in small quantity. If someone has suggestions for a possible sealed connector to use I’d be glad to hear of them.

Leave a Reply

You must be logged in to post a comment.