Wingsail Controller Evolution

The wingsail is mounted on ball bearing races, and must be able to freely rotate. It also has a trim tab that must be controlled.

My solution to this has been to develop a controller to operate a trim tab servo under the command of a radio signal of some type.

The Voyager Sail Controller is visible in the image of Voyager 2.0 sailing, as the green PCB in wingsail.

Voyager 2.0 with Sail Controller V1 fitted in the Wingsail 

The first designs used Bluetooth 4 as the communications link. The Voyager Sail Controller was set up as a Slave Bluetooth 4 device, connecting to the main Voyager Controller which was the Bluetooth  Master.

This worked well but the Bluetooth 4 modules had a continuous current drain of about 9mA while connected.

Prototype Wingsail Controller using Bluetooth 4

Voyager Sail Controller V0 using Bluetooth 4 - August 2018

Voyager Sail Controller V1 using Bluetooth 4 - March 2019

During 2019 we changed the main telemetry link to the vessel to be LoRa radio using the Ebyte devices. 

The Ebyte LoRa devices can be operated in a low power mode, where they wake up at predetermined intervals and check for a signal and then return to sleep. In practice, this yields an average current drain of around 6mA.

It also yielded the benefit that there are less components required on the Main Voyager controller, because the radio link to the wingsail is the same as the telemetry link to shore.

The only problem is the slow data rata rate and high latency. This yielded delays of around 1 to 2 seconds from when the wingsail should be responding.

Voyager Sail Controller V2 using LoRa Radio - May 2019

In 2022 the Bluetooth 5 module JDY-25M became available, and new Wingsail controller V4 was developed.

The JDY-25M Bluetooth 5 module has an idle current of around 1mA.

The low current consumption, combined with high data rate and low latency make a good option.

As of mid-2022, this is best version of the Wingsail controller yet.

When the wingsail is fitted with 2 x 2200mAHour 18650 cells, the wingsail has a projected battery life of at least 2 months.

This compares very well with the original Bluetooth 4 Wingsail controller having a battery life of around 8 days.

Voyager Sail Controller V4 using Bluetooth 5 - February 2022