Crystal Oscillator Frequency Counter Tester

[poppniete]

Hi folks,

I've ordered the same kit a few weeks ago and it did not work after putting it together.
In my case I tracked the failure down to the LED display being the cause.  They sent mie a KYX3561BS, which is the common anode variant, although it should have been a KYX3561AS, the common cathode version.

I fixed the problem by flashing "counter3.hex" and by making the circuit changes proposed in the readme file found here: http://www.qsl.net/dl4yhf/freq_counter/freq_counter.zip

COUNTER3 uses the same pins as COUNTER2, but the control
outputs are inverted to drive COMMON ANODE display.
In the circuit, use PNP instead of NPN for T1 to drive
the 5th digit of a COMMON ANODE display, furthermore
connect D1..D4 with reverse polarity, and connect D4
to Vsupp instead of GND.

I guess I have to make a donation to the original author DL4YHF not only for supplying the firmware but for fixing the errors of chinese kit suppliers

Regards,

Jan