20x2 i/o
- Thread starter jmumby
- Start date
Yes, all I/O pins can be input or output, except C.6 which is input only because of the silicon design.
With respect to HSEROUT, that's saying the command cannot be used to output data on the Download Serial Output pin ( leg 19 ).
As for pull-up and pull-downs with serial coms; it depends on what you are interfacing to and polarities involved. A SERIN pin, used by the program but not connected, should be pulled-down for Nxxxx polarity, pulled-high for Txxxx polarity, to remain in its natural 'idle' state.
With respect to HSEROUT, that's saying the command cannot be used to output data on the Download Serial Output pin ( leg 19 ).
As for pull-up and pull-downs with serial coms; it depends on what you are interfacing to and polarities involved. A SERIN pin, used by the program but not connected, should be pulled-down for Nxxxx polarity, pulled-high for Txxxx polarity, to remain in its natural 'idle' state.
Different pins in use. The "H" part designates hardware, so you must use C.0 for HSEROUT (pin #10), and B.6 for HSERIN (pin #12).
I never use pull-ups for serial comms.
Serial In cannot be used for anything else but that.
Serial Out can also be used for an Output only.
And as noted, C.6 is an Input only.
And, of course, +V and 0V cannot be used for anything else bar power supply.
BUT I am sure that you've already figured that one out.,
MPep.
westaust55
Moderator
i2c (as available on the hi2c pins) is also serial comms and needs pull-up resistors
Another rudimentary question I would imagine. Im talking to a device that requires DTR and DSR. The device is RS232 level rather than TTL. Would I pipe the DTR and DSR signals thru the other two level shifters on the MAX232? The datasheet says that RTS and DTR are the same so im just going to join those together.
Try looking here:RS232 pinouts
Gives reasonable descriptions and what pins/signals to connect together.
If you plan using DTR and DSR in your PICAXE program, then yes connect them through the MAX232 converter.
If you run out of converters, however, simply duplicate the download circuit. Remember to 'invert' the signal's polarity.
Gives reasonable descriptions and what pins/signals to connect together.
If you plan using DTR and DSR in your PICAXE program, then yes connect them through the MAX232 converter.
If you run out of converters, however, simply duplicate the download circuit. Remember to 'invert' the signal's polarity.