Hi Sean, we have now successfully crossed the Atlantic with pypilot!
Very happy with the steering aspect but the lack of working NMEA output over USB has been a major, major headache. We had to keep the old autopilot switched on to provide heading data for the instruments and for the radar, which doesn't work well without a heading input. It hasn't been good for the state of our batteries having the old system switched on and it still doesn't give us rudder data because the sensor is connected to the pypilot.
The pypilot seems incapable of connecting as a WiFi client to feed data into the xb8000 because there is nowhere to configure the nmea port number for client connection in the LCD interface. That would be the only alternative to nmea output over USB.
Using open cpn as a bridge is not a good solution. Firstly the radar and instruments would fall at the same time if the nav tablet fails. They are supposed to provide redundancy so there are two ways of seeing the data, not to work as a chain when any failed device can bring the others down. Also I have multiple devices which can run opencpn and no way to know which is on at any time. I couldn't set them all to echo the nmea because that would duplicate it when more than one opencpn is in use.
AIS data only comes from the xb8000 so that needs to be the main WiFi hub the tablets connect to. It would be unreliable if it passed through anything else. So autopilot needs to send heading and rudder via instruments to the nmea wired input of the xb8000. Xb8000 only supports 5 WiFi clients, another good reason to use wired connection and save those for the Android tablets (I use Android tablets and phones as instrument displays inside and outside so all 5 are needed)
Xb8000 must be access point not client because we use the Vesper watchmate app for anchor alarm etc.
Finally, the only opencpn devices we normally use on passage are Android, they only have one wifi interface. Adding a raspberry pi plus a second WiFi just to echo rudder data would be a big waste of precious battery power, sledgehammer to crack a nut and probably unreliable.
It's pretty standard for all autopilots to output rudder and heading as a minimum over wired nmea. the autopilot is very likely to be the only source of that data so feedback is unlikely. If its not wanted them the user doesn't have to connect it. Can we get that working as a quick solution until a fully configurable nmea system is working?
As regards the second rudder input, is not important but since you asked... our rudders are hydraulically connected and can get out of alignment so they each have separate sensors and displays to monitor that. Starboard sensor connected direct to an instrument which can output nmea. Port sensor connected to an autopilot which should then output nmea to drive the port instrument. If one ram or rudder fails we lock it as a trim tab and can steer with just the other rudder. It would be nice if we could fail over to the nmea from the instrument on starboard side if the directly connected port sensor fails but mainly we just need the nmea output working on the pypilot so there is something to drive the port rudder gauge.
Anyway, the TLDR version: tinypilot should be a drop in replacement for existing autopilots without reconfiguring everything else on board. Existing autopilots generally all output heading and rudder data over wired nmea so I think tinypilot should do that too (via USB)
Very happy with the steering aspect but the lack of working NMEA output over USB has been a major, major headache. We had to keep the old autopilot switched on to provide heading data for the instruments and for the radar, which doesn't work well without a heading input. It hasn't been good for the state of our batteries having the old system switched on and it still doesn't give us rudder data because the sensor is connected to the pypilot.
The pypilot seems incapable of connecting as a WiFi client to feed data into the xb8000 because there is nowhere to configure the nmea port number for client connection in the LCD interface. That would be the only alternative to nmea output over USB.
Using open cpn as a bridge is not a good solution. Firstly the radar and instruments would fall at the same time if the nav tablet fails. They are supposed to provide redundancy so there are two ways of seeing the data, not to work as a chain when any failed device can bring the others down. Also I have multiple devices which can run opencpn and no way to know which is on at any time. I couldn't set them all to echo the nmea because that would duplicate it when more than one opencpn is in use.
AIS data only comes from the xb8000 so that needs to be the main WiFi hub the tablets connect to. It would be unreliable if it passed through anything else. So autopilot needs to send heading and rudder via instruments to the nmea wired input of the xb8000. Xb8000 only supports 5 WiFi clients, another good reason to use wired connection and save those for the Android tablets (I use Android tablets and phones as instrument displays inside and outside so all 5 are needed)
Xb8000 must be access point not client because we use the Vesper watchmate app for anchor alarm etc.
Finally, the only opencpn devices we normally use on passage are Android, they only have one wifi interface. Adding a raspberry pi plus a second WiFi just to echo rudder data would be a big waste of precious battery power, sledgehammer to crack a nut and probably unreliable.
It's pretty standard for all autopilots to output rudder and heading as a minimum over wired nmea. the autopilot is very likely to be the only source of that data so feedback is unlikely. If its not wanted them the user doesn't have to connect it. Can we get that working as a quick solution until a fully configurable nmea system is working?
As regards the second rudder input, is not important but since you asked... our rudders are hydraulically connected and can get out of alignment so they each have separate sensors and displays to monitor that. Starboard sensor connected direct to an instrument which can output nmea. Port sensor connected to an autopilot which should then output nmea to drive the port instrument. If one ram or rudder fails we lock it as a trim tab and can steer with just the other rudder. It would be nice if we could fail over to the nmea from the instrument on starboard side if the directly connected port sensor fails but mainly we just need the nmea output working on the pypilot so there is something to drive the port rudder gauge.
Anyway, the TLDR version: tinypilot should be a drop in replacement for existing autopilots without reconfiguring everything else on board. Existing autopilots generally all output heading and rudder data over wired nmea so I think tinypilot should do that too (via USB)