Here ist the latest project, a cooperation with
We developed a bat-receiver (actually a "bat scanner") where
a microprocessor is not only being used for the frequency
display, it also takes over the control of the board, implementing some
interesting features. Software and board designed have already been finished.
Tony is using a different case and has made his own
The analog part of the receiver is still NE612-based, but the internal signal for
the mixer is being produced by a PIC-processor. So the final receiver does not
need any kind of adjustment (because of the tolerances of some components the
analog receivers all had slightly different min/max frequencies). Currently the
range is 10-80 kHz, including birds, frogs and insects in the 10-20 kHz range
(step size is 2 kHz).
A two-digit display shows the frequency in kHz.
Instead of a frequency dial this receiver now has three small pushbuttons
"up", "down" and "mode" for selecting the frequency, starting the scan mode
and entering the configuration menu.
The configuration is being stored in EEPROM and restored on the next
a board with all components (and external wiring)
There may be a slightly different version of the software for
recording-boxes (bat receiver with VOX-operated tape recorder).
This version will probably scan in 5 kHz steps, output timer beeps
every 15 or 30 minutes and output of the current recording frequency
when bat-calls have been detected. The timer beeps will help to find
the time of most activity and the frequency markers will at least
give some hints about the possible bat species. Currently this
software version is just being planned, but the hardware supports
it and if there is demand, I will program it.
the kit ...
... some hours later
Update: A small batch of professionally manufactured boards is ready now and
we have been working with the first receivers in the field. The costs for a
complete kit with case are about 60 Euro.
short video of the receiver in action (and see the real stars here)
seen from above: Tony (right) and Frank (left) working on a completely different project