FAQ – SailTimer Wind Instrument™
Solar charging & battery care
Please go to this page for the FAQs on solar charging and battery care.
Please go to this page for the Android FAQs.
How are True Wind and Wind Angle determined?
We had a newsletter explaining the various wind measures and how GPS is involved.
Should the RB battery connectors be under the nose cone or under the battery?
Why is the cover clear on the tail?
Solar panels are used as the tail in this innovative product design, so the cover over them is clear. It is opaque over the electronics on the new Wind Instrument RB since there are no relevant details there — but it still gives you a hint of what’s under the hood. Other than the solar panels, the tail is white to minimize heat build-up.
What mobile devices support Bluetooth 4?
iOS: The Wind Instrument can transmit directly the following devices or newer models: iPhone 4S, iPad 3rd generation, iPod Touch 5th generation, and iPad Mini. Android: The specifications of your device may indicate if it uses Bluetooth 4 (also called Bluetooth Smart, and Bluetooth LE – Low Energy). Bluetooth 4 works on Android version 4.4 (KitKat) and newer versions such as 5.0 (Lollipop) and above. If you need to check what version of Android you have, it is in Settings – About Phone.
Can Bluetooth 4 transmit from my mast height?
The Wind Instrument RB is designed for boats of all sizes including keelboats and bluewater multihulls. Bluetooth Low Energy (Bluetooth 4/5) has an official range of 330 feet+ (100+m) as shown on Wikipedia. The new Wind Instrument RB has a transmission distance for even the tallest masts: 100 feet (30.5m) typical with obstruction and 280 feet (85m) with line of sight. You can optimize the signal strength by placing the Wind Instrument on the masthead where it gets a direct view down below, rather than trying to send radio waves straight through the solid metal masthead. This is also easy to get familiar with on the ground before mounting.
Can I still use my boat's wifi network?
Yes, the Wind Instrument uses Bluetooth 4, so that you can still use your mobile device for wifi and/or internet access.
Should the Wind Instrument be visible under Bluetooth devices in Settings?
No. On Android and iOS, you should scan for the Wind Instrument in the API, not in general Settings on the mobile device. In iOS, after the Wind Instrument is connected to the API using Bluetooth, it appears on the list in Settings, but not before. That has a security advantage, so that others cannot see your Wind Instrument in their Settings.
If my mobile device is connected to the Wind Instrument on Bluetooth LE (4), can I connect to other Bluetooth 4 accessories at the same time?
Yes. One of the advantages of Bluetooth over wifi is that you can have multiple connections at the same time. (With wifi, you can only be on one network at a time.) So your mobile device can connect e.g. to a Bluetooth 4 GPS receiver, Bluetooth 4 speakers and the SailTimer Wind Instrument™ all at the same time.
How can I receive the wind data on several phones/tablets/watches simultaneously?
Bluetooth devices usually only connect to one device at a time. Wifi is a broadcast, but Bluetooth is usually 1:1. That is true for the Wind Instrument partly for security reasons, and also to reduce power consumption due to solar charging. But some apps can rebroadcast the incoming Bluetooth data on wifi, and can receive wifi data (https://wi-rb.com/apps/).
If any of your crew are using smartwatches, those are typically receive data from the the phone/tablet. So one person could have the phone/tablet in the cockpit, and another person could be wearing the watch up on the front deck. Some of the apps that can display wind data (https://wi-rb.com/apps/) do have watch apps. It is a function of each app though, so you would need to check a particular app to verify.
Then as another alternative, we also do have the accessory called the Air Link (https://wi-rb.com/sailtimer-air-link-features/) that can receive the Bluetooth data and retransmit it on wifi, for any number of devices to receive (using apps that can receive NMEA data on wifi).
So there should be several ways to accomplish this. :-)
Could I accidentally receive wind data from a neighbouring boat?
No, when you connect to your Wind Instrument, you can rename the connection (under the “i”), which makes it clear that you are connecting to your own Wind Instrument. The Bluetooth 4 protocol contains a number of measures to protect your data. For example, your transmissions from the masthead are encrypted. Also, to save power the Wind Instrument only allows one connection at a time (so no-one else can get your data).
Will the VHF antenna on my masthead affect the digital compass in the wind direction arrow?
No, we have not seen any examples of a masthead antenna creating Bluetooth interference or magnetic fields affecting wind direction.
How much space does the Wind Instrument need, for rotating?
Can I maintain the Bluetooth 4 connection when my tablet/smartphone goes to sleep?
Yes, the API will keep the connection running in the background even if you put your tablet/smartphone to sleep. That’s handy for crowd-sourcing your wind data while preserving battery power in your device. But when putting the tablet/smartphone to sleep, you can also press Disconnect in the API if you need to preserve power in the Wind Instrument (since it uses more power when connected).On iOS, If using the SailTimer app (or Charts Edition), your iPad/iPhone won’t automatically go to sleep. But if you manually put the device to sleep, the data connection from the API to the app is terminated. Therefore on iOS, leave the screen on the API if you want to put your iPad/iPhone to sleep and keep the Bluetooth 4 connection on.
My wind cups have started making sound when spinning; what can I do?
See the new stainless steel axle and wind cup bearing (bushing) in Accessories. The new axle fits all previous models of Wind Instrument. This would also be covered under warranty.
Are there privacy or security issues if I crowdsource wind data?
We respect your privacy. The Wind Instrument is also very secure, and uses encrypted data. You can share wind conditions for the live wind maps with no identifying information. Sharing your wind data is optional, with the Share button in the API. More details here.
The tail looks much bigger than the nose cone; do they balance?
Yes, the Wind Instrument is designed to be perfectly balanced, and has adjustments for balance. It is an optical illusion that the tail is heavier than the nose cone. You can easily stand it up and turn it around without attaching the mounting rod, as shown in this YouTube clip. The tail is thin, and has three large air gaps in it: one in the hollow between the solar panels, and two at the bottom of the board for the Bluetooth 4 LE antenna. Also, the battery is moved to the leading edge of the circuit board, close to the axis of rotation. The nose cone serves as a counterweight out on the end of the pointer to provide leverage and balance without adding too much extra weight.
Is there a smoothing function for the Wind Instrument?
Yes, there is averaging in the API: on the line with the name of the Wind Instrument at the right, click on (i). On the panel that opens (screenshot), there are some advanced settings including Wind Direction Smoothing. You can set the smoothing (averaging) period. This was originally in the iOS version of the API, but in Feb. 2016 is also being added to the Android version of the API (the next version after 2.0).
Do I need to protect the digital compass in the tail from magnets?
The wind direction is determined by a digital compass that is insanely sensitive, even though it is only about the size of the head of a pin. Like all compasses, it needs to be kept away from magnets, magnetic fields, speakers, hard drives, electric motors etc. In models up to 2018, the blue cap for the off-switch contains a magnet. So as noted in the Owner’s Manual (p. 11), it is important to only snap the blue cap into place on on the top edge of the tail section, but to otherwise keep the blue cap away from the electronics. You don’t need to worry too much about magnetizing the new Wind Instrument RB. It was mostly the steel case on the battery that could get magnetized on previous models, but the battery is in the nose cone now and is easy to remove or replace. Even if the battery in the nose cone did get magnetized, the magnetic field wouldn’t reach to the digital compass in the tail.
Does the digital compass work worldwide for wind direction?
Yes. Magnetic declination is the difference between true north (based on earth’s poles) and magnetic north (measurement of compass). This varies globally depending on your location. To preserve power consumption the Wind Instrument is designed to send the apparent wind to the API on a phone/tablet or Air Link, where GPS data is available. The API or Air Link then calculates the magnetic declination for your location.
What is the Cloud Server Activation on the order page, and why is it necessary?
With the Cloud Server Activation, we split the costs of the hardware and software. It is a way to reduce customs fees, taxes and duty for customers outside of North America. The cloud server just refers to the Wind Instrument software, which also gives you the option of viewing live wind maps online from a server. If you are in North America, this payment for hardware and software individually doesn’t affect you. You need both the hardware and software, and together they give you a price that is far lower than standard masthead anemometers.
How can my multiplexer or Raspberry Pi get data from the Wind Instrument?
The SailTimer Air Link™ accessory is the best way to get the data to your multplexer or Raspberry Pi. The wind data is sent from the masthead on Bluetooth 4 (Low Energy), to the Air Link. The Air Link can then retransmit on wires or wifi to your device. (Although there are Bluetooth 4 dongles available for the Raspberry Pi, there is no driver for the Bluetooth 4 data protocols and encryption used by the Wind Instrument. Bluetooth 4 is too new, and only has standard protocols for devices like wireless keyboards and wireless speakers.) Fortunately, the Air Link can send NMEA 0183 sentences from the Wind Instrument using TCP port 55556. Then on the Raspberry Pi you can use a command like “nc airlink.local 55556” to access the wind data. If your boat is in a place with wifi and internet access, the Air Link can also be accessed online, so that you can check wind conditions at your boat from home or work.
Is Audio Navigation speaking with magnetic north or true north?
What are the optimal settings for accurate conversions to True Wind?
Smoothing (averaging of wind direction) in the API app can help keep TWS independent from jumps in wind angle (e.g. due to vibration in high winds or on a coach boat bouncing over waves). TWS should be independent of boat speed, but may increase with less accuracy if AWA is jumping around. (TWS = True Wind Speed. AWA = Apparent Wind Angle.)
If smoothing is increased to average across 4 seconds, TWS is unaffected by boat speed and everything is very stable. However you may not want to do this because it makes the wind gauge respond more slowly. Smoothing over 3 seconds works mostly, but some spikes still sneak through. In our testing, that does not happen at 4 seconds.
In the API to get 4 seconds, consider the transmission rate and the smoothing over X transmissions. For example, if you have transmissions set at 5 Hz (5 per second), smoothing over 20 transmissions would give 4 seconds.
We haven’t changed this in the API, since users will usually want quick reactions — but we plan to do this when sending crowdsourced data for True wind speed and direction to the SailTimer cloud server. You have the option to set it in the Smoothing settings in the API if needed.