Lost Depths

[AnchorageGuy]

I have an older Raymarine ST40 depth sounder and until recently was getting my depth readings via a SeaTalk to NMEA converter by Raymarine and a Serial to USB converter to my laptop. All was working well for almost 2 years. Suddenly the depth stopped showing. When I connect the NMEA out from the Raymarine converter to my computer and use HyperTerminal I get this. I have rechecked and reconnected every wire and connection. The GPS outputs fine. Also replace the SeaTalk to NMEA box just in case that was the problem.

[Cheechako]

The first thing I do if the depth stops is to go down and scrape off the transducer underwater. Unless your transducer shoots thru the hull...

[AnchorageGuy]

The depth sounder is working just fine. We have only lost the depth readings to OpenCPN on the computer. Guess I should have been clearer. Chuck

[nohal]

Chuck...
What you show on the screenshot is totally broken, NMEA sentences have to be text and numbers. A bit cryptic, but readable...
Did you have the port speed etc. set correctly in hyperterminal? Did you try to use another Serial-USB converter?

Pavel

[AnchorageGuy]

Pavel, Thanks. I do know what the NMEA sentences should look like and yes the port setting is correct. When I connect just the GPS I get a good read in the HyperTerminal with everything correct and the GPS working fine with OpenCPN. This is through the same Serial to USB cable, so that's working. When I switch to only the depth sounder, what you see is what I get. I'm baffled since this has been working. The GPS is connected directly while the depth sounder is connected via the SeaTalk/NMEA converter, which I have just replaced in case it was bad. The depth sounder on it's own is fine and feeds data to the repeater on the flybridge. The SeaTalk/ NMEA converter is wired correctly. If not it won't read at all in the HyperTerminal. Chuck

[rgleason]

Does not look too good for your Raymarine output. I wonder if that is not producing?
--- What physical connections? Are they nice and clean?

[AnchorageGuy]

I pulled every connection apart, inspected, cleaned and put it all back together. No improvement. Chuck

[nohal]

Chuck...
Really hard to say without access to the hardware. If we are sure that the ST part is OK (and I believe it as even if it was broken, the NMEA should look like NMEA) and if we are reasonably sure it is not the converter box as 2 of them result in the same output, I would personally really try another Serial-USB converter and cables/connectors between the box and the converter. The electrical properties of the GPS serial port and the one in the box can be different which might (or not) cause a difference.
I'm afraid I can't suggest much more without connecting an oscilloscope to the box output...

Pavel

[a64pilot]

I haven't used a serial to USB converter in awhile, but if I remember right, they need a driver. Try un-installing and re-installing the driver.
They may also be hard to find now, If your going to be in PC this weekend and need one, I feel pretty sure I have one or two laying around and I could bring one.

[AnchorageGuy]

nohal, I was kind of afraid of that, but thought I would put it out there. Thanks for trying. Chuck

[AnchorageGuy]

Thanks a64pilot. The Serial to USB is working fine with several other connections to the computer so I don't think we will mess with it. I will probably upgrade the depth sounder soon anyway. We're in Carrabelle heading south. Chuck

[Dsanduril]

The screen shot looks an awful lot like disagreement over either baud rate or data structure (7 vs. 8 bits or parity). Since you are using Hyperterminal anyway, I'd open the connection using different settings. There are a lot of combinations, so I'd work from 1200 up to 9600 baud, then start playing with parity and data bits at different speeds.

Don't see how/why your SeaTalk bridge might have changed any of that, but the output certainly looks like that kind of garble, so I'd spend a little time seeing if you can hit on the right settings.

[irwin37]

Check your serial port settings, looks like you may have the wrong baud rate setting, could be on the receiving (laptop) end or the sending end.

Opps.....Guess I could have read the last post.

[AnchorageGuy]

Thanks I'll give it a try. Chuck