Good news for 433mhz RF!

Most of us are familiar with the issue of the Espruino getting bogged down dealing with random noise on RF receivers.

I was looking at the datasheet for the SYN470R, used in the good 433mhz receivers (the small yellow ones with the SOIC-16 package on them - these have at least twice the range as well, and are under $2/each on ebay), and came across this gem:

14.5. Data Squelching
During quiet periods (no signal) the data output (DO pin) transitions randomly with noise. Most
decoders can discriminate between this random noise and actual data but for some system it does
present a problem. There are three possible approaches to reducing this output noise:
1) Analog squelch to raise the demodulator threshold
2) Digital squelch to disable the output when data is not present
3) Output filter to filter the (high frequency) noise glitches on the data output pin.
The simplest solution is add analog squelch by introducing a small offset, or squelch voltage, on
the CTH pin so that noise does not trigger the internal comparator. Usually 20mV to 30mV is
sufficient, and may be achieved by connecting a several-megohm resistor from the CTH pin to
either VSS or VDD, depending on the desired offset polarity. Since the SYN470R has receiver AGC
noise at the internal comparator input is always the same, set by the AGC. The squelch offset
requirement does not change as the local noise strength changes from installation to installation.
Introducing squelch will reduce sensitivity and also reduce range. Only introduce an amount of
offset sufficient to quiet the output. Typical squelch resistor values range from 6.8MΩ to 10MΩ.

Sounds like we should be able to make 433mhz signals receivable directly on the Espruino with a decent receiver and a single resistor (soldering onto an SOIC package lead isn't too bad)!

All my good receivers are already in use, but I've got another 5 on order