[Mark McLeod]

Originally Posted by emusteve

I'm trying to read a group of 4 io pins to get a numerical value as the status of an outboard device. I'm trying it out using the edubot controller so I'm looking at io pins 1-4 which translates to PortA bits 0-3. I was trying to do the following:

sensor_value = (PORTA & 0x0f);

iIt compiles ok, but the result is always 0. I double-checked that I have set the pins to INPUT, and have set the number of analog channels to NO_ANALOG. sensor_value is an unsigned char.

I also tried reading the pins individually as rc_dit_in01 through rc_dig_in04 and got the proper values, so I know the hardware is ok. Anyone know what gives here? Any help would be appreciated.

We're doing the same thing with a BCD switch.

I tested this on the EDU controller and it worked.
With unconnected pins you get 0x0F
With dig I/O 1 signal-to-gnd you get 0x0E
With dig I/O 1&2 connected you get 0x0C

in user_routines.c, User_Initialization()
 
Set_Number_of_Analog_Channels(NO_ANALOG);	 /* See ifi_aliases.h */
 
IO1 = IO2 = INPUT;	 
IO3 = IO4 = IO5 = INPUT;
IO6 = IO8 = IO10 = INPUT; 
 
// IO3 = IO4 = OUTPUT;
// IO5 = IO7 = IO9 = OUTPUT; 
 
IO7 = IO9 = OUTPUT; 
IO11 = IO13 = IO15 = OUTPUT; 
 
// rc_dig_out03 = rc_dig_out04 = 0;
// rc_dig_out05 = 0;
 
 
in user_routines.c, Process_Data_From_Master_uP()
 
	PrintString((char *) "PORTA = ");
	PrintByte(PORTA & 0x0f);