2018-12-25, 10:52 PM
The problem with Seatalk is that it uses 9-bit sentences. The UART uses 8 Bits by default. I'm not an Arduino expert, but I think you can read 9-bit sentences with Arduino.
Another possibility is to use a SeaTalk to NMEA converter like this one https://www.ebay.com/itm/SEAYAK-Seatalk1...:rk:5:pf:0
or this more complete one: https://ocenav.com/en/base-stations-atm105a/, with which you can integrate all marine communication standards.
More complicated, you can read the pulses from the speed sensor directly with a GPIO from the Raspberry Pi. As the hall sensor produces, as you said, 12 Volt pulses. This voltage must first be reduced to the 3V input of the Raspberry GPIO, for example by using a voltage divider mounted as a pull down system,
![[Image: pull-down-abierto.png]](https://i.postimg.cc/Gpvf9rBg/pull-down-abierto.png)
although the best system is by optoisolation, for example with the 4n25 or better with the LTV817
![[Image: Raspberry-Optocoupler.jpg]](https://i.postimg.cc/8zzkhKdb/Raspberry-Optocoupler.jpg)
That if, it will be necessary to write a program in Python to read the pulses and to turn them into speed
Another possibility is to use a SeaTalk to NMEA converter like this one https://www.ebay.com/itm/SEAYAK-Seatalk1...:rk:5:pf:0
or this more complete one: https://ocenav.com/en/base-stations-atm105a/, with which you can integrate all marine communication standards.
More complicated, you can read the pulses from the speed sensor directly with a GPIO from the Raspberry Pi. As the hall sensor produces, as you said, 12 Volt pulses. This voltage must first be reduced to the 3V input of the Raspberry GPIO, for example by using a voltage divider mounted as a pull down system,
although the best system is by optoisolation, for example with the 4n25 or better with the LTV817
That if, it will be necessary to write a program in Python to read the pulses and to turn them into speed