Programming concept for a port

[RenesasT]

Hello All,

After long time, have a great day all.

I need your help. All suggestion would be greatful for me.

I am using renesas controller, I am taking data in Port lets say port 1 which is of 8 bits,

I am taking status of 3 sensors , which could be either high or low. i.e 0 or 1.

The sensors A, B, C are connected to port 1.0, 1.1,1.2 respectively.

I am reading port in 8 bit variable as sensor.

I am writing below program

sensor=P1;

Its like P1.7P1.6P1.5P1.4P1.3P1.2P1.1P1.0

It is working. Now thing is that. Now I need like P1.7P1.6P1.5P1.4P1.3P1.1P1.0P1.2 in the sensor.

What to write for that?

suppose Port 1=0x01 (00000001) , then I need sensor value as 0x02(00000010).
If Port 1=0x06(00000110), then I need sensor value as 0x05 (00000101).

Please help me.

 

[srizbf]

...I am reading port in 8 bit variable as sensor.

sensor=P1;

....
What to write for that?

suppose Port 1=0x01 (00000001) , then I need sensor value as 0x02(00000010).
If Port 1=0x06(00000110), then I need sensor value as 0x05 (00000101).

Please help me.

already sensor=P1;
you want it as 0x02.
It is an input port.

You have not described what you want ?

 

[KlausST]

Hi,

I really don´t know what you need.

The sensors are on bit 0, 1 and 2.
So at first I´d mask the three bits by ANDing port value with 0b0000 0111.
Then the result can only be 0...7
binary: 000, 001, 010, 011, 100, 101, 110, 111
Now you could do a switch/case processing.

Or use a table with 8 entries.

Klaus

 

[mfro]

sensor=P1;

P1.7P1.6P1.5P1.4P1.3P1.2P1.1P1.0

P1.7P1.6P1.5P1.4P1.3P1.1P1.0P1.2

What to write for that?

From what I understand, you just want bit 0, 1 and 2 shuffled around?
Of course you could shift around the resulting bits, but if there is no simple arithmetic to convert your port value to your expected signal value, I would just use a table to translate the lower 3 bits:

uint8_t table[] = { 0, 2, 4, 6, 1, 3, 5, 7 };

port = P1;
sensor = (port & ~7) | table[port & 7];

You'll need bit ops in microcontroller coding regularly. Get accustomed with them.