The Coach App does not capture data from local sensors but instead retrieves processed data from a Boat App. Transmission between the two Apps is achieved wirelessly over a WiFi connection, however no internet connection is required. No configuration aside from connecting the devices to the WiFi is required, connection between the two Apps is configured and established automatically when both are running.
The link between the two apps is error resilient and handles intermittent loss of connectivity gracefully. It’s also latency aware, meaning that the Apps compensate for the network latency to provide perfectly synchronized data to the Coach. When using quality hardware, a WiFi for on-water use can easily span 50 meters or more. Good signal quality is important to allow timely delivery of data packets from the Boat to the Coach App. This is especially critical if you want to record Rowing in Motion Videos. If you find the graphs in the Coach App stuttering, this indicates a problematic WiFi connection with intermittent drops of data packages.
Portable Access Points
The easiest way to setup a WiFi for Rowing in Motion is using a portable WiFi (sometimes called “MiFi”) access point with integrated batteries. These devices usually fit a SIM card and allow sharing a mobile data connection with a small numbers of WiFi devices. Rowing in Motion will not need an internet connection for realtime data transmission, so you can operate the portable WiFi access point without a SIM card just fine (though you may wish to do so for working with Analytics).
We have tried various mobile WiFi Access Points but found that some of them have bad antennas and provide insufficient range, so you need to be careful choosing one. We have made good experience with devices from Huawei such as the Huawei E5331 or Huawei E5220. They are fairly small and their battery lasts long enough for 3 to 4 rowing sessions.
If you have another device that works well for you, please let us know so we can add it to this list. With a portable access point you’re range is usually 30-50m.
Personal Hotspot connections work ok if you follow close behind the boat (20-30m) and are easy to set up. Personal Hotspot is only available on certain devices and must usually be allowed by your mobile carrier. While being easy to use and not requiring external hardware, Personal Hotspots most significant drawback is that it drains the battery very fast and provides a less stable connection than a dedicated WiFi access point.
Consumer-grade WiFi Access Points
By far the best solution is using a quality WiFi Access Point with at least two external antennas (MIMO, Diversity) on a battery or custom mobile power supply. We have made good experience with TP-Link Access Points that operate on 12V, so they can be directly attached to a standard 12V battery. With those Access Points, you can easily achieve a range between 50-70m and even more is possible with the right type of antenna.