Discussion in 'Ham Radio Discussions' started by PD9X, Jan 10, 2017.
Rats. Sorry !!
I have managed to drive the relays and such with an Arduino Nano, but am still having problems with the PLLs.
The EPROM and 80C31 are removed. I hope to make an Arduino plug in board to replace them.
It is quite a learning curve!
One problem was the 8525A has I2C, CBUS and the PLLs all on the same clock and data lines. The Arduino locks out the A4 and A5 pins (used for I2C) so they cannot be used for anything else once the I2C has been started. So far, I have not found how to turn the Nano procerssor's I2C hardware on and off.
So I've added an MUX..
and can select the function with...
digitalWrite(MUX0,LOW); // 0 = I2C, 1 = Other, 2 = +5V, 3 = gnd.
This looks to be working ok, but driving the 2 x MC145159 PLL chips (in series) has proved to be a problem for me as I have not figured out the numbers required as yet.
Just yesterday, I purchased a second one, an 8525B version, so I do need to get it all going.