Universal HAM radio/generator DDS Unit with AD9850 or AD9851
To demonstrate power of both PIC16F84 and AD9850(1) it was created probably
the most compact generator unit in the world which is usable for both HAM radio
equipment and universal signal generator.
The algorithm of the device is simple:
The LCD display works in 4 bite data transfer mode. 2 of 3 control lines are
shared with DDS unit. To allow maximum performance at the band reading inputs
there is a diode logic to recode band 1 to 8 into binary logic. The resistors
at the band inputs should be set according the voltage from band switch. In my
case it is 8 V, so there are 1k2 resistors.
The following picture is only application of that one for concrete case. The original PCB can be used, but it requires quite careful checking of all changes! (Sorry, I don't have time to draw new PCB, my experimental design I created with old PCB and "bird nest" approach...;-)))). |