Ask Sail: Dueling Sensors
John Clements, of Baja, California asks:
I am an avid weather watcher, and I’ve found some extra uses for my wireless temperature sensors. I’ve got one in the reefer, one near the engine and one to monitor the air conditioning. Each has its own readout, so I can easily monitor temps all around the boat, for less than $150 for all four units!
The problem is they all intermittently go on the blink about once every week for half a day.
Gordon West replies:
Each remote sensor transmits on 433 MHz, about once per minute. Their internal oscillator clock circuits may lose or gain a second or so every day, and there may be a period when two remote sensors are transmitting data at exactly the same time. This leads to scrambled reception and no readout on the displays. You can pull the batteries from all the sensors to reset their signal sequence, and then replace them with fresh batteries. But there is still no guarantee there won’t be a collision of signals in the future. To eliminate the problem you need to use wired sensors.