PCA9626 with pic18f45k80 are not working

[eeeahmet]

Hello,

i am new in forum. my code is

[PCM programmer]

1. Does your LED (on pin D0) blink correctly, if you remove all the i2c code ?

2. What is your crystal frequency ?

3. Why are you using the CANTX and CANRX pins for your i2c ?

[eeeahmet]

thanks your reply,

1. yes blink correctly
2. my crystal frequency is 16MHz and fuse 4xpll
3. I use because there is no pins i can use for i2c. Also i use hardware spi for mmc and i don't use can bus in this circuit
4. I use 10k resistors for pullup because i have seen datasheet application

5. yes my tris function is the same with you

but I realized my circuit voltage is down 5V to 4.5V i guess the circuit has some short cuts i will check tomorrow. What do you think about it?

thanks again PCM programmer

[PCM programmer]

Yes, I think correcting your power supply problem is the first thing you
should do. If possible, use a +5v voltage regulator, such as LM7805
or a similar regulator. Or, use a +5v regulated wall transformer.
But the +5v must be stable.

[eeeahmet]

i checked it and solved the problem. the circuit voltage is 5V now but there is not still blink.

what can i do some else

[PCM programmer]

[Ttelmah]

I'd guess you are working at 3.3v?.
If so you need to significantly lower your I2C resistors.
The pull up provides a current to pull the line high. At 100KHz (slow), 10KR, is just about 'OK' for a slow I2C bus, with limited capacitance, and 5v supply. However for 3.3v I2c, even with only 30pF total capacitance, at 100KHz, you get a _maximum_ resistor value of 6.67KR. Typically 4K7R, is a good 'safe' value at 5v, and is acceptable at 3.3v, if you have a short bus, unless you are pushing high speed, or have an exceptional level of capacitance. However 10KR, is too high to be safe. I'm guessing the example you used was at 5v....

Then You are using address A2. So you have the binary pattern 0b 101 0001 on the select pins?. A0, A4, and A6 high, and the other pins pulled low. Remember the select pins are the high seven bits of the address.

Lower your I2C bus resistors, and run the I2C bus scanner program published by PCM programmer (in the code library). If it finds the device, you will _know_ what address it really is at. If not, then you know you have a hardware problem.

Best Wishes

[eeeahmet]

hi,

i realized my adress is not a2. it is 2a and i use 5v voltage level.

i changed pullup resistors an i checked it with oscilloscope high and low level very stable now.

i have tried i2c scanner and now comminication is working very well.

but still no blinking rgb leds.

i think my code is wrong iam sure that now.


i2c_start();
i2c_write(0b00000110);
i2c_stop();

its software reset adress


i2c_start();
i2c_write(0x2a);
i2c_write(0x00); // Mode 1 address
i2c_write(0b01101111); // oscillator settings normal mode
i2c_stop(); // Stop
delay_ms(1); // delay at least 500 us
its configure mode1 register and set oscillator settings of ic


i2c_start(); // Start
i2c_write(0x2a); // Slave Address
i2c_write(0x01); // Mode2 register address
i2c_write(0b00100000); // Outputs change on STOP,
i2c_stop();
its configured mode 2 register and change status of led with stop command or ack bit.

thats mean this configure settings are pca9626_init()

after i have tried this
i2c_start();
ack=i2c_write(0x2a);
i2c_write(0x1d);
i2c_write(0xff);
i2c_stop();
normaly leds open now but there is nothing.

final part of my code is

#include <18f45k80.h>
#device adc=10
#device *=16

#Fuses HSH,PLLEN,NOPUT,NOIESO,NOFCMEN,NOBROWNOUT,NOWDT,NOMCLR,NOEBTRB,NOEBTR//,INTRC_IO

#use delay (clock=64M)

#use I2C(master,scl=pin_b2,sda=pin_b3,fast=1000000)

int1 ack=0;

void main ()
{
PORT_D_PULLUPS(true);
output_a(0x00); output_b(0x00); output_c(0x02); output_d(0x03); output_e(0x00);
set_tris_a(0b10000001); set_tris_b(0b00000011); set_tris_c(0b10010000); set_tris_d(0x00); set_tris_e(0x00);

//ds1307_init(); // install DS1307

output_low(pin_d0); // Led power is ON
output_low(pin_d4); // OE pin low

i2c_start();
i2c_write(0b00000110);
i2c_stop();

i2c_start();
i2c_write(0x2a);
i2c_write(0x00); // Mode 1 address
i2c_write(0b01101111); // oscillator settings normal mode
i2c_stop(); // Stop
delay_ms(1); // delay at least 500 us

i2c_start(); // Start
i2c_write(0x2a); // Slave Address
i2c_write(0x01); // Mode2 register address
i2c_write(0b00100000); // Outputs change on STOP,
i2c_stop();


while(true)
{
// CHASE control
i2c_start();
ack=i2c_write(0x2a);
i2c_write(0x1d);
i2c_write(0xff);
i2c_stop();
if(ack==1)
output_low(pin_b5);
else
output_high(pin_b5);
}
}

pin_b5 is ack check pin and its show me ic sending me ack bit

[Ttelmah]

Ouch. Are you trying to make the MMC harder?.
Have you got the MMC working?.
Seriously, if not, re-think and work at 3.3v. It makes SD/MMC, about 50* easier.....

You have got OE pulled up?.
You need a short pause each time between I2C_STOP, and I2C_START. The chip specifies 4.7uSec for standard mode I2C between these. You have pauses in several locations, but not each time.
Your software reset is 'wrong'. You need to select the reset address, and then send 0xA5, then 0x5A, then stop. Otherwise you are not resetting.
You haven't set a group duty cycle or frequency for blinking, or enabled any individual output, so not surprised it doesn't do anything....

[eeeahmet]

Thanks for your answer.
Yes i work before sd/mmc and sd card work 3.3v pic is 5V. spi communication wires have got level shifting mosfet and 4k7 pullup.

No OE pin has not got a pullup resistor.


I tried your way but there is no blink anyway but your code more sensible.

[Ttelmah]

OE _requires_ a pulldown. The LED's won't ever light without it.....
The signal needs either to connect to the processor and be driven low, or be pulled down.

Best Wishes

[Ttelmah]

Just as an 'add on' to this.
The point about a 'pull up', is if you are using a processor pin to control it, then the pull up ensures it is 'off' when the processor is not working. Ideally you want to let it go high as soon as power fail is detected, otherwise the driver can keep driving as the power fades away, which can cause some problems.

Best Wishes

[eeeahmet]

thanks Ttelmah for your answer

I already driven low with pic. That pin is not open drain but i tried pulldown and pullup but no change. I checked package and pin layout but there is not any mistake. Already i said the ic sends me ack so i have a communication with ic. I don't understand where am i making a mistake.

[Ttelmah]

The classic thing at his point is to try a much simpler test. Set just the first, to feed off it's own PWM, and program this to a fixed level.

Best Wishes

[eeeahmet]

Hi,

I2C_start();
ack=I2C_write(0x2a);
I2C_write(reg_number);
I2C_write(value);
I2C_stop();

now ack bit is '0'

but


I2C_start();
I2C_write(0x2a);
ack=I2C_write(reg_number);
I2C_write(value);
I2C_stop();

ack bit is '1'

i dont understand