40 input portc
- Thread starter senyabeb
- Start date
westaust55
Moderator
First use the dirsc to set the required pins as inputs
Eg: dirsc = %00000000 ; set all 8 pins of port c to inputs
then for example,
Let b0 = pinsc
From that, bit0 will hold the state of portc pin 0, bit1 will hold the state of portc pin 1, etc
Eg: dirsc = %00000000 ; set all 8 pins of port c to inputs
then for example,
Let b0 = pinsc
From that, bit0 will hold the state of portc pin 0, bit1 will hold the state of portc pin 1, etc
40 pin pic portc
Hi.
thanks for the reply
I've tried that , its ok with the new (28 pin) small surface mount pic
but I've a job with one of the old larger 40x pin pics. maybe the larger one can't support
b0=pinsc ?
ie
' to load portc
dirsc = % 00000000
let b0 = pinsc <= syntax error !!!!!
it don't compile highlights line 2 ..... syntax error ! ??
regards eric
Hi.
thanks for the reply
I've tried that , its ok with the new (28 pin) small surface mount pic
but I've a job with one of the old larger 40x pin pics. maybe the larger one can't support
b0=pinsc ?
ie
' to load portc
dirsc = % 00000000
let b0 = pinsc <= syntax error !!!!!
it don't compile highlights line 2 ..... syntax error ! ??
regards eric
westaust55
Moderator
Differences in Port C for 28X/X1 and 40X/X1 parts
The difference is that with the 28X/X1, that the “standard inputs as used by most commands such as serin are on port C and the same pins sare funcationality with signals such as PWM, hserin/out and the i2c plus SPI comms signals.
For the 40X/X1, those same “standard” inputs are on port B and now port C is a separate port which can act as simple IO but is the connections for those same PWM, hserin/out and the i2c plus SPI comms signals.
The difference is that with the 28X/X1, that the “standard inputs as used by most commands such as serin are on port C and the same pins sare funcationality with signals such as PWM, hserin/out and the i2c plus SPI comms signals.
For the 40X/X1, those same “standard” inputs are on port B and now port C is a separate port which can act as simple IO but is the connections for those same PWM, hserin/out and the i2c plus SPI comms signals.
40X portc
Hello again
I have 12 ls373 transparent latches, 6 configured as input and six as o/p. bussed on portc
with an ls154 I can write to each o/p and i/p using portc with the 28pin sm chip (using
%0000000 and %11111111 etc. (using OE and monostable to CLK) 8bits at a time.
with the 40X can write 8bits to portc and read in from portc only on a pin at a time basis
I wanted to configure the 40X chip to read 8bits into portc
ie
'b5=pinsc
I must be stupid cos I still don't get it !
regards Eric
Hello again
I have 12 ls373 transparent latches, 6 configured as input and six as o/p. bussed on portc
with an ls154 I can write to each o/p and i/p using portc with the 28pin sm chip (using
%0000000 and %11111111 etc. (using OE and monostable to CLK) 8bits at a time.
with the 40X can write 8bits to portc and read in from portc only on a pin at a time basis
I wanted to configure the 40X chip to read 8bits into portc
ie
'b5=pinsc
I must be stupid cos I still don't get it !
regards Eric
westaust55
Moderator
I think that it may not be possible. If someone has it working I am sure they will advise.
pinsc is not referenced in the manual in the way you are trying to use it.
With the 40X or 40X1, the commands
pins = the input port when reading from the port
outpins = the output port when writing to the port
pins = b0 or Outpins= b0 operates on (writes to) the output pins of Port B, and
B0 = pins operates on (reds from) the input pins of Port D
BUT, pinsc is always looking at the same port. (Port C) so I can see that it may not work.
While the logic in terms of which side of the “=” the word pinsc is on could work there are no examples in the manual for reading in from portc in the manner you want. Unfortunately I am not home at the moment to try it out.
pinsc is not referenced in the manual in the way you are trying to use it.
With the 40X or 40X1, the commands
pins = the input port when reading from the port
outpins = the output port when writing to the port
pins = b0 or Outpins= b0 operates on (writes to) the output pins of Port B, and
B0 = pins operates on (reds from) the input pins of Port D
BUT, pinsc is always looking at the same port. (Port C) so I can see that it may not work.
While the logic in terms of which side of the “=” the word pinsc is on could work there are no examples in the manual for reading in from portc in the manner you want. Unfortunately I am not home at the moment to try it out.
As covered by others, careful reading of the manual and testing in the editor shows that portC on the 40X1 won't work the way you want - will do all the pinsc/dirsc things except the one you want.
Can you re-arrange which ports the connections are on to achieve the functionality?
You also have the option of checking each pin individually, and if necessary, creating a binary map in b5.
Can you re-arrange which ports the connections are on to achieve the functionality?
You also have the option of checking each pin individually, and if necessary, creating a binary map in b5.
No reason "Let var = PINSC<cr><lf>" shouldn't be supported as far as I can see as it's just a special syntax case in the assignment parsing, unless there's something peculiar with the parsing engine.
In fact it would be possible to use PINSC as if it were a variable in expressions in most cases by detecting a reference to PINSC, prefixing a "PEEK $07,infra" and using 'infra' / 'keyvalue' as the actual PINSC variable. That it corrupts the 'infra' variable can be noted in the manual and only a small minority of people ( I'd say none ! ) would likely be using 'infra' and PINSC in the same expression. That way it would also be possible to have "IF PINSC = $xx THEN".
The same could apply to "LET var = outpins" rather than "READOUTPUTS var", but as I'm not having to do the work I would say "READPORTC var" would be an acceptable compromise and in line wth existing practice and convention.
I'd personally take the trick of using 'infra' ( or some other temporary variable ) to the next level and allow commands to be used as functions, for example ...
LET b0 = READADC(1)
LET b1 = PEEK($07) ^ $FF
When there's no following maths that can optimise to what the existing commands are, otherwise prefix that command using the temporary variable then use that in the rest of the maths. As with unary operators (NOT,DCD) only allow functions at the start of the line.
In fact it would be possible to use PINSC as if it were a variable in expressions in most cases by detecting a reference to PINSC, prefixing a "PEEK $07,infra" and using 'infra' / 'keyvalue' as the actual PINSC variable. That it corrupts the 'infra' variable can be noted in the manual and only a small minority of people ( I'd say none ! ) would likely be using 'infra' and PINSC in the same expression. That way it would also be possible to have "IF PINSC = $xx THEN".
The same could apply to "LET var = outpins" rather than "READOUTPUTS var", but as I'm not having to do the work I would say "READPORTC var" would be an acceptable compromise and in line wth existing practice and convention.
I'd personally take the trick of using 'infra' ( or some other temporary variable ) to the next level and allow commands to be used as functions, for example ...
LET b0 = READADC(1)
LET b1 = PEEK($07) ^ $FF
When there's no following maths that can optimise to what the existing commands are, otherwise prefix that command using the temporary variable then use that in the rest of the maths. As with unary operators (NOT,DCD) only allow functions at the start of the line.