I popped in the 1.8342MHz oscillator (after tying OE high) and the MAX3110E (after tying
high) and started to see if I could get communication to work.The first thing I did was try to configure the MAX chip. It took a couple of tries to get everything all set. Here is the sequence that I need to do:
Then this code sets the baud rate top 9600:
I had some trouble at the beginning with the actual communication. To start, I connected the RS232C lines to the RX and TX pins of the MAX3110E. Oops. They actually take the 0-5V IO from the buffers (RS232C-TTL inverters) that also live in the MAX3110E. I was supposed to go through those and then to RX and TX. I think I had mechanical connection problems with the port (just sticking wires into holes on the M/F gender changer). And, of course, I was afraid I might have fried the RX and/or TX ports.
So I backed up to do what I should have done. Work in stages instead of trying to get it all at once.
I routed RX to TX and sent data (replace the flashprog.exe wp16 83 c0 with flashprog.exe wp16 83 80) and flashprog.exe wp16 83 a with flashprog.exe wp16 83 30) where 30 is the digit ‘0’. And indeed, I received the data I sent. So I knew RX and TX weren’t fried.
Then I connected RX and TX to the buffers and tied the other ends of the buffers together. Again, I received the data I sent. So I knew the buffer circuits weren’t fried (at not totally fried).
Then I tried to just receive on the RS232C from puTTY. I was finally able to get data. Finally, I connected the transmit side up. And ‘0’ popped up on puTTY’s screen. Just as I’d hoped.