Hi all,

I have small skid steer machine which I have modified to take control from two Arduino's using HC-12 wifi communication with software serial. So I have a controller with Arduino Mega, HC-12, LCD, pot and two single axis joysticks which transmits analog signals to the Arduino Mega mounted on the machine. PWM outputs then appropriately drive each hydraulic solenoid to control direction & speed. The pot value controls engine revs. This works fine.

The HC-12' are half duplex and so simultaneous data transmission is not possible. The controller transmits, the machine receives.... simple as that.

I want to be able to send engine fuel level, water temp and oil pressure back to the LCD on the controller without causing any latency / lag or delay to the skid steer, thus maintaining control functionality and safety.

I know the HC-12 are transceivers and so can send and receive, but the delay or induced stop in machine control while engine values are sent back to the controller is unacceptable.

Has anyone any ideas on how I can achieve my goal?

Thanks

 

How long is the delay while you send back your data?
If you cant simply leave all the control inputs as they are for that long then you have no option but to have two seperate channels of communication, on in each direction... See telemetry and video from RC drones.

Have you considdered splitting up the telemetry in to small chunks and sending it that way. you would still get short breaks in your control signals, that would need to ride through but they would be very short, imperseptable to an operator I would expect.

Of course you must also impliment some form od watchdog to stop the machine if some time expires between commands but again that would only need to be the time to send a byte or two of telemity data. All sub second stuff...

Is that any help?

 

Depending on how long the delay between sending data back to the controller and continueing feed of control values to the machine I might be able to get away with it. Would we be talking <100ms all round trip?

How would I go about recording the latency of sending a value through the wifi?

Thanks