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NahanniV · 09-05-2018, 14:40

Quote:

Originally Posted by boat_alexandra

...
Not sure how you would connect the i2c intertial sensors.. so that is likely the only part you would have to do something to resolve.
...

Is the pilot code reading the i2c inertial sensors directly ?
I thought heading could come from NMEA or SignalK ?

seandepagnier · 09-05-2018, 19:40

The nmea spec does not define the fields needed for inertial units so you would need to invent your own. There are a few fields for pitch and roll, but I have many more.

signalk can definately do it, but it would be a network socket which is both unreliable and not guarenteed delivery on time which is really bad. signalk over a serial port is a bad idea without
checksums, and because of the readable data format, the messages are quite long which would make a measureable lag even at 115200 baud, so you would have to go much faster.

So basically either way you will get some amount of lag either a little or a lot, and to minimise it would probably be more annoying than just getting a raspberry pi zero W for $10

I don't say it's not possible, but I don't suggest windows unless you have direct i2c or other low-level periphial access. The time from inertial measurement to motor reaction is critical and if it is slow, it would degrade the autopilot performance. As it is, the motor is also controlled through a hardware serial port which has very little delay and I tested this vs USB.

Furthermore, I don't know how to set processses to have real-time priority with guarenteed execution on windows like they are on linux.

It can be made to "work" reading gyro data from web sockets, just like having a very loose linkage in a windvane with too much play works, but steers not as well.

I'm not sure windows is a suitable platform. Don't expect me to implement it, but I will do my best to answer questions if you decide to. pypilot is portable and should run on anything and it's free software so you can make it work.

NahanniV · 10-05-2018, 06:17

Can the PyPilot control be made dock-able like the dashboard ?

I also find a Bar Graph style Rudder Angle Indicator quite informative.
Are you planning to implement rudder feedback ?
I think using rudder feedback to limit rudder angle is a better solution than using limit switches; Easier to install and gives more function.

seandepagnier · 10-05-2018, 06:48

I already support rudder feedback, and produce nmea sentences for opencpn. You can also use switches as well, or neither, and in that case rely on overcurrent protection which actually works pretty well.

NahanniV · 10-05-2018, 09:53

Is your hardware reading the ruder angle ? If so, what sensor is used ?
Or is it getting the information from somewhere else ? Like NMEA or SignalK ?

seandepagnier · 10-05-2018, 11:52

Right now, the motor controller has 3 optional wires. These supply 5v power, ground, and read an analog voltage for the rudder position. You can use a 5k ohm potentiometer, or linear hall sensor.

rgleason · 18-05-2018, 06:46

Sean, I compiled pypilot v 0.5.000 for Windows and put in release tab here
https://github.com/rgleason/pypilot_pi/releases

Is this plugin supposed to move the the website downloads page? If so, should I move it out of the Development Beta Plugins and into the regular Plugins section?

rgleason · 18-05-2018, 07:06

Quote:

Originally Posted by boat_alexandra

Right now, the motor controller has 3 optional wires. These supply 5v power, ground, and read an analog voltage for the rudder position. You can use a 5k ohm potentiometer, or linear hall sensor.

There are many types of linear & rotary position sensors. With a rudder you would want a linear sensor, but would that also be best for a steering quadrant?

Two that I found without considering cost, voltage etc.
Position Sensors
https://www.rls.si/eng/products/rota...netic-encoders

Approaches for position sensing
https://sensorso.com/measure-position.html

Found this 12" stroke 350 lb linear actuator
https://www.amazon.com/ECO-WORTHY-Ac...osition+sensor

Maximum current draw = 3 Amps, Maximum Load = 330lbs(1500N).
12V motor has gearbox and is rated to hold up to 330 lbs when not moving
he housing thickness is 2mm, motor power is 30w 12v 400 rmp.
The Max. Load for Push application is 1500N, and for Pull application is 1200N.
It's IP54.
To adjust the stroke: this actuator can adjust the stroke by dismantle the actuator and there is a black line to adjust stroke inside actuator.
Or pls check our actuator with controller http://www.amazon.com/dp/B00XHDAFY8, you only need to assemble a limit switch to adjust the stroke.

Is it fast enough? comments: Great actuator, slow, but works great for application.
Very strong, use as chicken coop door actuator and it hasn't skipped a beat...
too slow purchased faster actuator

rgleason · 18-05-2018, 07:30

Here is a much more expensive linear actuator with a built in hall effect sensor.
These probably would not be adequate for wheel quadrant, as pneumatic actuators are normally used.
https://www.amazon.com/Progressive-A...re-bullets-btf

Here is a well documented linear actuator 12vdc or 24vdc
http://www.midwestmotion.com/dclinear.htm

Opie91 · 18-05-2018, 07:44

Rick,

Are you talking about connecting this to the quadrant, below deck? If so one major hurdle to overcome is the fact that these cheap actuators do not have a clutch that allows them to disconnect remotely allowing free steering while the pilot is not in use.

This option puts you in the big money.

seandepagnier · 18-05-2018, 08:53

Quote:

Originally Posted by rgleason

Sean, I compiled pypilot v 0.5.000 for Windows and put in release tab here
https://github.com/rgleason/pypilot_pi/releases

Is this plugin supposed to move the the website downloads page? If so, should I move it out of the Development Beta Plugins and into the regular Plugins section?

Yes, the plugin is already on the website download now.