CTP Autopilot problems

[Bill O]

Martin,
That was an excellent presentation on how it is to be connected!


Bill O.

[MartinR]

In the simple version, the leads from the motor would just go to the pypilot contoller, brown and black in my case.

Here the brown and black go to the center terminals of a double pole/double throw switch. The grey and green go to one side of the switch (they come from the CPT motor controller). On the other side of the switch the cables from the pypilot motor controller are connected. Switch is in separate location.

I have a second switch that does the same with th power supplies. Switches over the power to either Pypilot motor controller or CPT.

[Bill O]

The pypilot can do the simple point/shoot and other course corrections as the CPT controller and obviously much more when hooked up correctly to gps and wind.

Was there any reason you kept the CPT controller?

Fairly simple swap out to put a new Pi zero in place if the brains ever went down.



Bill O.

[Exile]

Originally Posted by hpeer

A64, it really, really is only 2 wires.

Funny, but I've been corresponding with both PelagicAP (brains) as well as Lecomble & Schmitt (muscle), and they've been trying to tell me the same thing. "Only 2 wires."

Originally Posted by MartinR

Yes, in principle it is only two wires. In reality you want to be able to switch between the pypilot controller and the CPT controller and this means 4 wires. It is a very simple thing to do.

This is the hangup for me, although probably only in my own mind. And although you're describing the process for the CPT I think the same basic procedure applies with any sort of actuator, in my case two different sets of brains for one muscle (below decks ram). Fwiw, Pelagic has cautioned me to use two completely indpt sets of wires for data & power, and to transition from the B&G brain over to the Pelagic brain in one fell swoop. They have recommended Bulgin waterproof connectors but I don't see why a far less expensive (and convenient) DPDT switch as you used wouldn't also work.

I drilled a hole in the bottom of the CPT drive unit and installed another watertight cable gland.



A 4*1.5mm cable is connected to A) the drive motor B) the CPT motor controller output. The other endof the cable is connected to two DPDT switches, that lets you choose controller and supplies it with power. A single 4 pole DPDT switch would be better, but I took what I had. You can either have this switch in the CPT drive unit, or like me outside somewhere in the cockpit.



This is most helpful. Thank you. But at the risk sounding like even more of a noob than I already know I am, I'm getting a bit tossed over some vocabulary. In essence, you're talking about connecting the two drive motors of the Py and CPT; what Py calls the 'Motor Controller' and CPT the 'Drive Box'. IOW, the two 'computers/controllers' of each unit simply connect to their respective drive motors. You are simply adding 2 wires to the 2 already in place in the drive motors in order to go back & forth btwn the Py and the CPT systems. The CPT (wheel) actuator (muscle) stays in place. I don't want to create any confusion with my wording so please correct/clarify as needed.

The rest is just installation of the tinypilot unit and motor controller. Pretty straightforward. My tiny pilot is situated next to the Nav screen.



The whole process took me about 2 hours, most of the time spent pulling a data cable from the Nav station to the motor controller.

As Bill O mentioned, I'm assuming pulling this data cable wouldn't be necessary if you had data transmitted over wifi since the Py has the ability to receive it wirelessly? Am I understanding this correctly?

Finally, I'm not quite understanding how one controls the Py. Is it necessary to run it via OpenCPN or OpenPlotter, or can it -- like the CPT -- be manually operated for a simple compass course? If not, are there other PC or device-based programs it can be operated from?

[Bill O]

Exile,
Watch this basic pypilot (=tinypilot) setup video, maybe it will be easier to see how it works.
https://www.youtube.com/watch?time_c...ature=emb_logo


Bill O.

[Exile]

Originally Posted by Bill O

Exile,
Watch this basic pypilot (=tinypilot) setup video, maybe it will be easier to see how it works.
https://www.youtube.com/watch?time_c...ature=emb_logo


Bill O.

The video shows a remote control which the website says is not included but also says any IR TV remote would probably work after programming. It also suggests platforms other than OpenCPN & OpenPlotter but doesn't list any. Also unclear about the need for a rudder sensor. There are other videos I haven't watched and of course forum information. Lots to learn and probably worth it given the potential & price.

[Bill O]

Originally Posted by Exile

The video shows a remote control which the website says is not included but also says any IR TV remote would probably work after programming. It also suggests platforms other than OpenCPN & OpenPlotter but doesn't list any. Also unclear about the need for a rudder sensor. There are other videos I haven't watched and of course forum information. Lots to learn and probably worth it given the potential & price.

That was an older video and it now comes w/an IR sensor and remote. Some people comprehend things better when they see it and that's why I linked the video. There are other videos here if you want to watch them.

Openplotter on a RPi (~$35 + a SD card) is easy to do and is a good mini winter project.

You don't necessarily need a rudder position sensor, but we have one only to see how much rudder we have and if we need to adjust the sails. IMO I'll take all the info I can to make everything work better and for a $5 add on to the motor controller its worth it (if you don't already have one). If you have OCPN or Oplotter hooked up, no need to buy a gauge as the rudder angle is displayed on the dashboard.

Bill O.

[MartinR]

Originally Posted by Exile

As Bill O mentioned, I'm assuming pulling this data cable wouldn't be necessary if you had data transmitted over wifi since the Py has the ability to receive it wirelessly? Am I understanding this correctly?

Finally, I'm not quite understanding how one controls the Py. Is it necessary to run it via OpenCPN or OpenPlotter, or can it -- like the CPT -- be manually operated for a simple compass course? If not, are there other PC or device-based programs it can be operated from?[/COLOR]

The cable is from the tinypilot to the motor controller. These are two different units. The tinypilot is accessed by WiFi and can be controlled in different ways. Directly from Openplotter. By a web interface from whatever browser. I use my phone. By infrared remote.

The web interface is simple and has soft buttons for changing course.

[MartinR]

Originally Posted by Bill O

The pypilot can do the simple point/shoot and other course corrections as the CPT controller and obviously much more when hooked up correctly to gps and wind.

Was there any reason you kept the CPT controller?

Fairly simple swap out to put a new Pi zero in place if the brains ever went down.



Bill O.

I kept the CPT controller for redundancy. Also nice to have a fixed autopilot control at the helm. I use the pypilot 90% of the time, though.

[geoleo]

WHAAAAAAAAAAAAAA??? I thought there CPT s were the greatest since sliced bread!! apparently not. Best pilot I ever had was a ray 7001

[hpeer]

They were, new way to slice bread, much sexier!

[a64pilot]

So as a sort of other way to skin a Cat, it should be child’s play to connect a CPT drive motor to an existing autopilot?
The control / signal commands should work?
Other than to keep an autopilot from binding up and either damaging itself or the rudder, why is a position indicator needed?

[MartinR]

Originally Posted by a64pilot

So as a sort of other way to skin a Cat, it should be child’s play to connect a CPT drive motor to an existing autopilot?
The control / signal commands should work?
Other than to keep an autopilot from binding up and either damaging itself or the rudder, why is a position indicator needed?

Position indicator is not needed. Pypilot measures the current and cuts power if too high. This set point is adjustable. No risk of damaging anything.

Not sure about the CPT controller, but would think same same. Also there is a shear pin on the drive unit that will give in case of excessive force.

[Bill O]

Originally Posted by MartinR

Position indicator is not needed. Pypilot measures the current and cuts power if too high. This set point is adjustable. No risk of damaging anything.

Not sure about the CPT controller, but would think same same. Also there is a shear pin on the drive unit that will give in case of excessive force.

Agree the rudder position indicator is not needed, but a nice to have for sail trim and when backing the boat into a slip. Besides the settable high voltage parameter (if the rudder goes hard over/hits end stop), the position indicator allows one to have a "soft stop" feature and shuts the motor down before the rudder goes hard over. Ours is set at 30 degrees, while hard over is 35 degrees. This helps avoid the massive power spike if it ever tries to go hard over (never had a situation yet where it even came close to hitting the soft stop).

Another use for the position indicator is to provide an actual value (degrees) of rudder movement/oscillation to help adjust the gain(s) for various sea states. Could arbitrarily eye ball the gain adjustment, but seeing the amount of rudder movement is helpful.

Power consumption monitored by the pypilot is yet another parameter for setting the gain, which I do not believe the CPT provides. This is a standard feature in the pypilot and don't need a position indicator for this function.


Bill O.

[a64pilot]

CPT belt jumps if it gets bound up.
I use a tie wrap on a wheel spoke as a rudder indicator.

I’m leaning towards getting a B&G autopilot next year and using it to drive the CPT drive, then having a second CPT in a box down below as backup.