Change receiver frequency on Fine Offset unit?

[L.F.]

My console is a W8681 with 868.3 MHz receiver frequency. The touch screen was playing up so I bought an apparently identical replacement, labelled N98GY. Unfortunately this has an 433.9MHz receiver! The PCBs are slightly different too. I wondered if there is any way of replacing the 433 receiver unit with an 868 one? I can't swap them over as the pinouts are quite different.

[AllyCat]

Hi,

No, that's very probably "impossible". The reason is because it's not just the radio frequency that is different, but also the "wireless protocol" and the hardware functions. Over the last few years Fine Offset appear to have been "cost-reducing" their hardware; the older models use an "intelligent" radio receiver that (temporarily) stores the whole data packet, which is then sent to the microcontroller when requested (perhaps via a SPI data bus).

However, it does appear that the "latest" stations (e.g. Maplin from a few years ago, Clas Ohlson for a few months) now use a "simple" receiver (with only 3 or 4 pins) which potentially could be swapped. Unfortunately, neither retailer has actually changed their stock numbers, although at least the Clas Ohlson Consoles do look different (blue backlight).

So, for your case, I recommend that you just bite the bullet and buy a new external transmitter module from Maplin for £15. I'm fairly sure that the old (cabled) sensors are all compatible with the new(er) temperature/humidity/transmitter modules. Or, return the Maplin Console and try to obtain one of the "old" 868 MHz Consoles, for example via ebay.

Cheers, Alan.