Return of the YAPP

[alan-bc]

I'll look into it when I get to a computer. The simulator definitely used the hardware of another design. I might have got the link to the hardware wrong.

Thank you so much for the time!

As it happens, more diligent internet searching has turned up the schematic for your Autopilot Remote, which includes your "generic" SeaTalk reader circuit as well as a few more bits clearly intended to write to the bus.

So I think I'm OK!

For this part of the project.

Sadly, I have another problem that's going to take some thinking. One of my SeaTalk gauges is an ST40 BiData, which displays Depth, Speed and Temperature. (In Raymarine speak, "Bi" apparently means three.)

The temperature determination is by a simple resistive sensor and ONLY that sensor is used to determine the water temperature. Worse, the ST40 broadcasts what it knows to the SeaTalk bus, so any other display that might be coerced into displaying the temperature will only display what the ST40 tells it to.

I could just remove the ST40 from the bus, but then I'd lose something important; Speed Through the Water messages, which are required for determining True Wind Speed and Direction.

It looks like I'm going to have to build a SeaTalk to SeaTalk filter.

This project just got more complicated ...

 

[northwind]

Thank you so much for the time!

As it happens, more diligent internet searching has turned up the schematic for your Autopilot Remote, which includes your "generic" SeaTalk reader circuit as well as a few more bits clearly intended to write to the bus.

So I think I'm OK!

For this part of the project.

Sadly, I have another problem that's going to take some thinking. One of my SeaTalk gauges is an ST40 BiData, which displays Depth, Speed and Temperature. (In Raymarine speak, "Bi" apparently means three.)

The temperature determination is by a simple resistive sensor and ONLY that sensor is used to determine the water temperature. Worse, the ST40 broadcasts what it knows to the SeaTalk bus, so any other display that might be coerced into displaying the temperature will only display what the ST40 tells it to.

I could just remove the ST40 from the bus, but then I'd lose something important; Speed Through the Water messages, which are required for determining True Wind Speed and Direction.

It looks like I'm going to have to build a SeaTalk to SeaTalk filter.

This project just got more complicated ...

If your goal is to replace the water temp sensor with one for the engine coolant, why don't you simply use the pins on the back that the sea temp sensor is connected to? Reverse engineering seatalk to do this is way ott, its also a pain as the bi data will not display speed without the thermistor connected on the back, you can't then squirt a temp reading in from elsewhere to bypass this value as its read internally on the instrument.

 

[AngusMcDoon]

So, your SeaTalk Simulator seems perfect.

I'm writing because the page from your old (OLD) website does not include a schematic, it says to just use the SeaTalk2USB circuit.

The Seatalk Diagnostic project uses the Seatalk2USB hardware. The Seatalk simulator project uses the autopilot remote hardware without the push buttons or LED (although they do no harm if they are there). The schematic and layout are files for DesignSpark (and a BOM XL spreadsheet) are here...

miniwinwm/YAPP

Note this comment from an earlier post:

- The processor part number on the schematics is not always correct as I was lazy when copying and pasting designs. The non USB ones all work the the PIC18F26K22 and the USB ones work with the PIC18F2550.