i2C 2 Slave and IR Led Problem

[emaxxenon]

Hello,

I have 1 master and 2 slave cards.
I use pic18f25k22 on all cards.
There are 16 ir leds in slave cards.
Master sends information to slave cards to turn these leds on one by one.
It reads one by one and sends it to plc.
It worked correctly in simulation tests.
I tested it for 3 ir leds on the board and it worked correctly.
But now I am having trouble for 16 ir leds when I test it on pcb.

Why could it be?

Master Code:

[Ttelmah]

You need to get rid of the ISR code in the master.

I2C_ISR_STATE, is for a _slave_. The '0' condition that starts it, is an
address match (so the slave address being received). Similarly the 0x80
state is an address match with the R/W bit set. Again _for a slave_.
On the master _you_ initiate all transfers, so there is no ISR. and the state
won't work correctly.

Currently you will get interrupts when the receive buffer fills, but the
state will not be correct, and then the byte will be read in two places. In
the main that is actually triggering the transaction, and then in the ISR
again. Not how this needs to happen.

There is a requirement in I2C, of a pause between a stop, and the next start
this is 4.7uSec for standard mode and 1.3uSec for fast mode. You are not
putting any pause at all at this point.

[emaxxenon]

[Ttelmah]

You do not use I2C_ISR_STATE in a master.

The whole point is in a master _you_ initiate all transfers. There is no
interrupt use for something happening on the bus because things only
happen when _you_ do them.

Just take the byte value you are reading back in the loop and set your
LED's from this.

I'd suspect your big problem is the lack of delay between stop and any
subsequent start. This is the 'bus hold time'. Required, but most
simulators don't bother to check this. The real chips will though.....

[emaxxenon]

[Ttelmah]

You need to get rid of all your SSP ISR code in the master.
Ensure INT_SSP is disabled.
Then where you have:

data = i2c_read(0);


Use the value read here to control the LED's.

Then wherever you have i2c_stop(), add a line afterwards with

delay_us(2);

You never read from T_SLAVE1. Does this ever return anything?. If so
you need to add code to read this.

[emaxxenon]

[Ttelmah]

What resistors are you using on the LED's?.
Because you use 'input_state', if the LED pin does not go high enough top be
seen as a '1' the code will return the wrong value. So if the pins are
'overdriven', there will be issues.

[emaxxenon]

[PCM programmer]

Here you define various slave addresses in the Master code:

[emaxxenon]