Adding wireless remote to a old Autohelm 3000

[sailorchic34]

Originally Posted by Saqqara

It is probably better to replace the brain entirely and use only the muscle from the old tiller pilot.

What you may be looking for is a project called Pypilot created by Sean Depagnier. It is currently in the process of being integrated with the Openplotter project. Both may be of interest to you.

OpenMarine

pypilot - open source marine autopilot

Sean has achieved what you are describing with three motors:
1) simrad tp22
2) autohelm linear ram
3) raymarine wheel pilot 4000mkii


While the technologies are open, he also sells some hardware on Tindie.

I will be trying this later this year. It's fairly easy to make a DIY autopilot with more features and for far less money then paying big money for a "Marine" AP.

[jpuype]

Originally Posted by sailorchic34

Yes they had a separate unit /box that interfaced between the nav interface to Autohelm unit. That "black box" took the nav course from the reciever and send left and right input to the old autohelm unit, much like the remote I added does manually. Not at all the same as sending NMEA0183 data direct to the autohelm.

....

But yes you could build a micro controller to decrypt NMEA0183 signals and then send left and right rudder commands to the old autohelm head unit.

However if you add a compass and rudder position (easy to do) and motor controller ...

One fellow even has cross track error built into his DIY controller. Quite advanced. Just that you can't send NMEA0183 digital data to the old autohelm as the old units did not have digital inputs or a processor as we thing of one.

But the old analog type autohelm does do a nice job of maintaining course with simple (by today's standard) and in my case discrete parts.

Hi Sailorchic,

Now I get the feeling we are talking the same language.

I just want to be able to for the thing to listen to the plotter. Or OpenCPN in my case (Running OpenPlotter). But I ideally I would also want to keep the manual control, when solo-sailing it is quick to set up without the need to boot the Rpi and set the whole thing up in the software, if all I want it is to keep a steady course when I'm on the foredeck changing a Jib.

So in my case a simple box decoding the NMEA signal from the RPi, and sending the right signals into the headunit would be perfect.

Is the information about the output from the Z075 interface (input on the headunit) available somewhere, what voltages/current on what pins?

Sincerely,
Jurgen

[sailorchic34]

Originally Posted by jpuype

Is the information about the output from the Z075 interface (input on the headunit) available somewhere, what voltages/current on what pins?

It depends. In racer99's unit, he has a newer (much cleaner) version of the autohelm 3000 with 5 wires for remote. mine is 4 wires for 1 degree port and starboard and 10 degree port and starboard. Those and engage and disengage are the only signals you can send. It also varies depending on which model of the 3000 you have. BTW the earily 4000's work mostly the same.

So you really can't send a data signal but you can activate a 1 or 10 degree turn in either direction. That is pretty much it.

There really isn't a schematic of the signals, for me it was all guesswork and touching wires together to see what did what.

[takemore]

Originally Posted by jpuype

Hi Sailorchic,

Now I get the feeling we are talking the same language.

I just want to be able to for the thing to listen to the plotter. Or OpenCPN in my case (Running OpenPlotter). But I ideally I would also want to keep the manual control, when solo-sailing it is quick to set up without the need to boot the Rpi and set the whole thing up in the software, if all I want it is to keep a steady course when I'm on the foredeck changing a Jib.

So in my case a simple box decoding the NMEA signal from the RPi, and sending the right signals into the headunit would be perfect.

Is the information about the output from the Z075 interface (input on the headunit) available somewhere, what voltages/current on what pins?

Sincerely,
Jurgen

Hi Jurgen,

I am new to this forum and just found this thread and your post. Your approach is exactly what I want to do. My boat has this old trusty rusty Autohelm 2000 and in my opinion it is rock solid, bulletproof and easy to handle and I would be happy to keep this control head in service.
The NMEA 183 NAV Interface was the Z050 and it was connected to the Remote plug. So this tells me that the only thing it can do is to trigger the + or -1 deg input to compensate the Xtrack error to the way point.
This should be easy to do with some kind of Arduino board and a little software which translates the Xtrack error input into some analog trigger output pulses.
Just a thought ....

Ingo

[jpuype]

Originally Posted by takemore

Hi Jurgen,

I am new to this forum and just found this thread and your post. Your approach is exactly what I want to do. My boat has this old trusty rusty Autohelm 2000 and in my opinion it is rock solid, bulletproof and easy to handle and I would be happy to keep this control head in service.
The NMEA 183 NAV Interface was the Z050 and it was connected to the Remote plug. So this tells me that the only thing it can do is to trigger the + or -1 deg input to compensate the Xtrack error to the way point.
This should be easy to do with some kind of Arduino board and a little software which translates the Xtrack error input into some analog trigger output pulses.
Just a thought ....

Ingo

Hi Ingo,

I'm pretty sure it is the Z075. The manual of the Z050 which is available online states it takes NMEA0180 (not NMEA0183) data, the Z075 is the updated device that does also take NMEA0183.

Anyway, I think all it probably would take is an arduino (Uno? Micro?) and a couple of 12v relays as hardware.
The old Nav Interface box also had a rotary control to indicate speeds that (assume) world influence the rate of turn, and the delay to allow for reaction time. I assume one could delete that one and use the 'Speed through water' (RHW) or 'Speed over ground' (RMA) NMEA sentences.

If you want you can PM me your e-mail adress and we can discuss this further in private ...

Jurgen

[Boston Blackie]

Great stuff Sailorchic! Brilliant to breathe new life into old gear. Good on ya.

[jpuype]

Originally Posted by radams

I’m a new member, so hello everyone!
I’ve got Autohelm 3000 with 5 pin socket for remote controller, been trying to ad remote and I think I did something wrong. I connected 5 pins according to scheme that I have found on another forum (1 pin common and four for proper buttons on main unit).

Does anyone know wher I could possibly find the schematics for this 5 pin layout? I'm trying to rig up something for my old Autohelm 2000, but I can't seem to source this shcematic.

Sincerely,
Jurgen

[racer_99]

Hey Jurgen,

I can possibly look it up for you, but it's pretty straight forward if you open up the unit.
In any case, don't waste time on implementing NMEA 2 Autohelm - been there, done that. And it is not worth the effort.

Hooking up a wireless remote is cool, I would do that again. But I canceled the interface (hooked up to the Raspberry) stuff. It works not accurate and sucks in general.

And to make things clear: The original interface does the same stuff (I own one) and sucks the same way. Can't compete with a modern unit.

Cheers, Andy

[Pendragon35]

Would it be difficult, in your opinion, to change the wired remote for the Simrad WP 32 to a wireless unit? I have the WP 32...(works fairly well) and I have the wired remote. But the connector is broken, so I have to rewire the remote to WP32 connection in any case. Any thoughts that a non-electrical engineer could understand?

[sailorchic34]

Originally Posted by Pendragon35

Would it be difficult, in your opinion, to change the wired remote for the Simrad WP 32 to a wireless unit? I have the WP 32...(works fairly well) and I have the wired remote. But the connector is broken, so I have to rewire the remote to WP32 connection in any case. Any thoughts that a non-electrical engineer could understand?

Oddly enough I looked into that. I had an old Simrad wheel pilot with the wired remote. The remote is a Serial interface, that is a 4 wire, plus, minus, and two wires for transmit my guess it sent nmmea 0183 bus. So it's not really simple to connect a wireless remote to it.

When my Simrad died, I went back to the autohelm 3000. I'll probably add a relay card to my new Homebrew autopilot that I'm still dinking around with.

[Norsailor]

I am new to this forum and have been following this thread with interest.
I have been using the Autohelm 3000 since 1978 and it has worked beautifully all these years. This season however it goes off course now and again without any corrective inputs from the controller, and it does not revert to stby.
Any hints from the forum what may be the cause? Also, is there a schematic of the controller available on the net?

[sailorchic34]

If it always turns to One Direction less than the other it's probably the power transistors where one is going bad or gone bad. The autohelm 3000 has very few parts. Voltage regulator the H Bridge power transistors and a monolithic chip that is now made of unobtainium.

There are two tip120 and two tip125 Darlington power transistors. They are dirt cheap and fairly easy to replace once you take the board out of the case. A $20 desoldering iron and a $20 soldering iron is all you need to remove and replace the four power transistors. There may also be two small capacitors adjacent to the four power transistors that should be replaced as well if they are burnt.

On the other hand if it makes random changes of Direction both port and starboard then the monolithic chip probably has gone bad and you're done.

[Norsailor]

Thanks for the advice sailorchic34. I'll gather up my courage and open the box!

[Norsailor]

I have opened the controller box and found no burned components. However, there were pieces of a flat round plastic cover loose in the box. I was unable to locate the missing 1/4 of this piece. The box has never been opened, so it should be there somewhere.
The remaining pieces fit on top of the mag sensor and has obviously been a cover of some kind for protection. There is a plastic screw that goes through the sensor into the balance weight and this also has gone through the plastic cover.
Now the weight was not tight against the sensor, but could be tightened by turning the screw.
Could the fact that the weight was loose have influenced the behavior of the
controller? Also, is this cover plate essential for the functioning of the autopilot?

[sailorchic34]

The top cover is really just for protection. You can't really tell if a Darlington transistor is functioning or not without testing in circuit. Which is hard to do when you don't have all the tools. Assuming the heading sensor, is mounted so it freely swings, it should work ok. Generally if a Darlington is bad if it turns less in One Direction then the other. This is a symptom of one or more bad power transistors in the h-bridge. the four Darlington transistors form the H Bridge which is common in bidirectional control of 12 volt Motors.

What you have is two tip120and two tip125 wired so that one set gives you forward and the other set gives you reverse on a 12 volt motor. When a Darlington transistor starts burning out one side will turn slower than the other. This manifests as the helm turning One Direction More than the other and not holding course. It's hard to test which one is bad so I just replace all four, when that starts happening. Just remember to replace like with like. That is the 120 and the 125 look the same except for the text on the front of the case of the transistor.

The old autohelm 3000's were prone to burnout darlington's if the Helmsman turn the wheel well the autopilot was engaged. Don't ask me how I know this. the key is to never turn the wheel manually when the belt drive is engaged as that will generate a reverse voltage that can damage the darlington's. It may take several attempts doing that before it starts mis-functioning. that is actually a weakness and all autoPilots.