Display analog output proplem

chilly85 said:

Hi all,
I'm working with ADC in PIC16F877. The output is written on PortC in 8 bit.Could I display this output in 3 bit? For example
PortC = 11111111 -> PortE = 111
PortC = 01111011 -> PortE = 011
PortC = 00010001 -> PortE = 010
Could I do something like this? (I checked but not worked)

Code:

movlw B'01111011'
xorwf PortC,w
btfss status,z
movlw B'00000011'
movwf PortE

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chilly85 said:

Hi Eric,
I would like to send the output from PIC to computer by parallel port
But in parallel port I have only 3 bit (3 pin ) to read this data.
That's why I have to change from 8bit to 3 bit

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ericgibbs said:

You understand you can only represent 0 to 7 states with 3 bits.

Divide the 255 value by 16, right shifts required.

Q1: why have you only got 3 bits available on the PC's paraport.?

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Pommie said:

If you have only 3 bits then send it serial. Use the bits as Enable, Clock & Data. The enable will allow you to recover if a bit is somehow missed when windoze goes of on one of it's tea breaks.

Mike.

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chilly85 said:

In the parallel port I have 8 pin for input and output.But I used 5 pins for output already. So I have 3 pins left for input

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Nigel Goodwin said:

Do you have a serial port?, that would make everything far simpler for you, on both the PIC and PC sides.

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ericgibbs said:

If I follow correctly, you dont understand the parallel port configuration.

Can you say how you are using the '5 pins'.?

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chilly85 said:

I'm not sure what I'm doing is correct or not. Each I/O pin of parallel port I connect to outside circuit by a wire. So I can use each pin separately (from D0 to D7)

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Nigel Goodwin said:

Data is data, it's up to you what you do with it once it's in the PC - I've no idea what Labview is capable of, but Hyperterminal will read the data and store it in a file.

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ericgibbs said:

hi,
D0 thru D7 are normally configured as PC output pins.

They can be configured by the PC's program as inputs if required.

It would help if you could post a sketch of what you have connected to the port.

EDIT: this table may help.

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