Monday, July 1, 2019

Tinypilot Installed and Working

Sean's Tinypilot is installed and steered from Okinawa, Japan to Southern Taiwan. I had a number of issues wit the rest of my navigation setup, but the tinypilot steered all the way.

My new Octopus hydraulic steering pump
 I mounted the steering pump on the aft bulhead of the engine room below the water-lift muffler. There was a by-pass valve above. I replaced it with the new hoses. The 3rd hose is the vent and runs up to the wheel steering pump in the binnacle. The power wires run to a 30 Amp fuse on the forward bulkhead of the engine room. The control wires run through the bulkhead to the motor controller on the other side, in the dry, clean area.

Sean's large motor controller
The large motor controller mounted on the outside of the aft bulkhead of the engine room where there is little chance of getting splashed with salt water or worse. On the bottom are the 12volt power wires coming in and the 2 wires to the motor. On the top the serial control cable up to the tinypilot in the cockpit. I had to extend the serial line to about 6 meters. The other wire is the home-brew rudder position sensor under the aft berth next to the rudder post.

Rudder position indicator before installation
The rudder position indicator is just a precision potentiometer tied to the rudder post. The pot is wired as a voltage divider across 5 volts giving an output ranging from 0.1 to 1.1v a 10k pot is probably best. My 5k pot needed resistors added to each side to get the range set.

Keyboard and mouse for OpenCPN and Tinypilot
The tinypilot is double sticky taped in position on the front of the dodger. The serial cable and a USB power supply. I intend to add wire clips screwed to the hatch frame, but haven't finished yet.

Tinypilot and it's remote
 A closer view of the tinypilot display and the Raspberry Pi Zero W under neath. It is currently running in the Access Point (AP) mode. So it needs to listen for UDP broadcast packets and forward the GPS and AIS data to the opencpn computer mounted above.

Opencpn and my Garmin 152H GPS

Opencpn and my Garmin 152H GPS are mounted at the top of the dodger enclosure. I thought they would be safe from wave splashes there. They are, but they white paint reflects a lot of light making them difficult to read in the daytime.

Normally opencn runs on an Orange Pi PC 2, an H5 cpu quad core 64bit ARM chip. But it's SD card memory is failing so I have backup Orange Pi PC Plus, (32bit) and also a Raspberry Pi 3B+ that is new.

In the past I've only run opencpn standalone. But with the Tinypilot I am trying openplotter on the RPI, but I don't have an evaluation of it yet.


  1. Great article about your pypilot install, as you said in the forum, there is very few real installs documented, thanks for sharing yours.
    I am going to do as you, I have just not decided how big hydraulic pump I need.

    Finclipper 35

    1. Thank you. My decision on the pump was because a friend's 51 foot ketch didn't steer well with an RPU80 but did with the RPU160. The guidelines I found for my boat suggested it was on the border between the two sizes. So I went with the larger one with the adjustable flow rate.

      My wheel is 5 turns, lock to lock. And a 20 cubic inch cylinder. I have not had a chance to test and adjust the flow yet. I think about 11 seconds should be correct.