They are for a hot air balloon temperature reporting system. I use a
Dallas DS18S20 digital sensor to a PIC and then to the MIRF. The
temperature is transmitted to an LCD in the basket, about 50 feet away..
I've just received the MIRF's so I haven't finished the software.
I spent about 100 hours trying to get cheap 433mhz units working well.
Even with manchester coding and multiple samples I couldn't get
reliable RF transfer. I did get the units to work by sending a pulse
width modulated signal where the pwm width represented the
temperature. But because of receiver "switch on" delay I had to
calibrate the unit with an oil bath to translate sent pwm to received
value.
I understand the nRF2401 are becoming widely used for short distance
data transfers. Each transfer is very few bits, but the rapid update
rate makes it useful for systems like remote keyboards.
Its interesting that Norway, producers of the nRF2401, has a rapidly
growing high tech industry.
--- In Homebrew_PCBs@yahoogroups.com, "alan00463" <alan00463@y...> wrote:
>
> --- In Homebrew_PCBs@yahoogroups.com, "bob_ledoux" <bobledoux@p...>
wrote:
> >
> > I just bought the Sparkfun MIRF units. They are nice. I've been
> > experimenting with cheap RF units and the antenna requirements can
> > make or break the whole system. The MIRF have them built in, making
> > much simplier implementation--once you get past the configuration
bits.
> >
> I take it you're referring to the nRF2401A transceiver pair pictured
> here: http://www.sparkfun.com/shop/index.php?shop=1&itemid=396
> ?
> 1Mbps is indeed an impressive throughput for $19.95. What exactly
> are you using them for, if you don't mind my asking?
>
> Alan
>