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???
07/17/08 16:41
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 		 #156807 - the cable appears to be correct
Responding to: ???'s previous message
3 goes to 2 and 2 goes to 3, ground is in the right place.

I rechecked PCB layout and found no mis-connects.

My scope shows the signal at the right place on the receive end of the cable.

The only strange thing is that when the null modem cable is connected to my PC and I turn off DC power to my board the Power On LED stays lit until I close hyper terminal. This LED is across the 5V regulator output. The 5V regulator, on my power layout, is powered from a 12VDC regulated wall wart.

Removing this wall wart - PC still connected with hyper terminal on - keeps the LED lit. PC still connected and hyper terminal turned off and the LED turns off.

Somehow 5V from my PC is feeding back through the Maxim chip and providing 5VDC to the entire board.

The DB9 connector on my board only has pins 2,3, and 5 connected to anything. Pin 5 is ground.

List of 32 messages in thread
TopicAuthorDate
SCON code question - data not seen            01/01/70 00:00      
   do you use a proper level convertor?            01/01/70 00:00      
      new cable            01/01/70 00:00      
   two different lever convertors            01/01/70 00:00      
   Check pins on cable            01/01/70 00:00      
      the cable appears to be correct            01/01/70 00:00      
   is data correct on the scope?            01/01/70 00:00      
      analog -vs- DSO            01/01/70 00:00      
         Triangular??            01/01/70 00:00      
         analog scope            01/01/70 00:00      
            oops - use 0x55            01/01/70 00:00      
   check Flow Control            01/01/70 00:00      
   Basics            01/01/70 00:00      
      Thanks Jon            01/01/70 00:00      
   Program works            01/01/70 00:00      
      feed through that wasn't            01/01/70 00:00      
         Correct spelling            01/01/70 00:00      
            just for the numbers or all characters?            01/01/70 00:00      
               In your case, to all            01/01/70 00:00      
                  fixed and not fixed            01/01/70 00:00      
                     not in that code            01/01/70 00:00      
   read mov data, data instruction            01/01/70 00:00      
      biblical            01/01/70 00:00      
         mov direct, direct instruction            01/01/70 00:00      
            to solve this            01/01/70 00:00      
            We talk of mnemonics            01/01/70 00:00      
               what matters is inside mcu            01/01/70 00:00      
                  The manufacturer defines            01/01/70 00:00      
                     Motorola versus Intel            01/01/70 00:00      
                  amateurs might hve some such, but no ..            01/01/70 00:00      
                     the assembler I use            01/01/70 00:00      
            no, it will not            01/01/70 00:00      

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