My company is developing an on-water force measurement system for rowing (the sport). We have the sensors and general circuits to support them completed; however, we are encountering a hurdle adding wireless communication to the system. What we need to do is transmit 5Kbps from 8 rower sensors. This data must be received by the individual rower displays about 5 feet from each sensor and by a “hub” unit held by the coxswain, which is up to 40 feet away for the farthest rower.
We have bought some radios from RF Digital (RFD21733) and have been trying to get these to work for our application. With the radios incorporated onto our circuit boards and nested in our devices (on the sensor; in an LCD display box), we are getting up to 100 feet range between transmitter and receiver. However, as soon as we go out on the water with these prototypes, the range drops off to unacceptable (15 feet?). When we put the sensor on a rower in the back, the coxswain screen 40 feet away gets absolutely nothing. We have tried everything suggested by RF Digital (everything that is possible within our space constraints) to make these modules work, but the tests on water seem unaffected. If we put the transmitter on a rower close to the coxswain, the coxswain does receive full data. But not from the rowers in the back!
Can anyone recommend a radio system that will work more reliably for our application? Here is the CAD drawing of our sensor (3D pdf along with an explanatory jpeg) and a diagram of the wireless distances. Any help you can suggest is much appreciated.
Thank you!
