Help for the I2C communication!

Ttelmah · Guest

First check that you are usig the right address. PCM_programmer, has the right address. The address is 0x44, with then the read/write bit added below this, so it ends up being multiplied by two for sending to the chip.
Your code would not work, if the address was right, since you never set the chip to return data.
PCM_programmers functions look right. Try using the command write function to set the mode you want, and then his read function.

Best Wishes

PCM programmer · Joined: 06 Sep 2003 Posts: 21708

I'm assuming that he only wants to read the two diodes, so I have
the code to send the command, placed within the "read diodes" function.

I'm not sure what the state of the ISL29001 chip is, upon power-up.
It's possible that it comes up in the "power down" state. The data sheet
isn't clear on this. It might be that you have to send the "Reset"
command to remove the "power down" state, before you can talk to
the chip with i2c.

Also, the schematic on page 10 of the data sheet shows that you have
to connect the Power Down pin to ground. (The chip can be put in
a power-down state either by a software command or a hardware pin).
If any of those pins are not connected correctly, the result might be
to read all FF's back.
http://www.intersil.com/data/fn/FN6166.pdf

Kyaw Kyaw · Joined: 17 Dec 2006 Posts: 15 Location: Singapore

Hi all,
Thanks for ur supports. But now i try to run with PWM Programmer's code and i made all the setting correctly according to the schematic shown in the ISL 29001 datasheet. Actually I want is to get the Diode1 Data only because I want the light intensity value for control. Could you please make a check for the timming diagram of ISL 29001 included in page 6 of datasheet? I think we need to make acknowledge after sending the device address (0x44 + Read/Write) and after power down command. Thanks for consideration of my problem.

It may be the fault of my IC ISL 29001 because it is too small and I mounted in socket PCBvia soldering. But I check with the camera to see whether it is connected proprely to the socket PCB or not. I didn't see any fault.

Thanks and Best Regards,
Kyaw Kyaw.
_________________
Thanks and Best Regards,
Kyaw Kyaw.

PCM programmer · Joined: 06 Sep 2003 Posts: 21708

Kyaw Kyaw · Joined: 17 Dec 2006 Posts: 15 Location: Singapore

Hi PWM programmer,
I didn't change anything except the PIN Assignement for RS 232 mode because I used B0 and B5 to communication with computer. The rests are still the same as u made, even the ISL 29001 address (0x88 for read and 0x89 for write) commands. Unfortunately it still show FFFF (hex) for data reading. I also tried to send power down mode (0x8c) after sending the write address command. At that time it didn't show anything even the data value of FFFF(hex) or sample sentence. I also suspect on the IC soldering. This IC is very tiny one and I also try my best to solder it. Do you have any idea for power down mode. Thanks for ur support and considering my problem. Below is the code i tried to test.

#include <16F877A>
#fuses HS, NOWDT, PROTECT, BROWNOUT, PUT, NOLVP
#use delay(clock=20000000)
#use rs232(baud=9600, xmit=PIN_B0, rcv=PIN_B5)
#use i2c(Master, sda=PIN_C4, scl=PIN_C3, FORCE_HW)

int16 result=0;

VOID main()
{
WHILE(1)
{
prINTf ("\n\rHello World Testing ISL 29001\n\r");

i2c_start();
i2c_write(0x88); // Send the ISL29001 address
i2c_write(0x8c); // send power down signal
i2c_write(0x30); // Set internally timed
i2c_stop();
delay_ms(2500);

i2c_start();
i2c_write(0x89);
result=i2c_read();
i2c_stop();
printf ("\n\r data1 value1 is %x\n\r",result);

delay_ms (1000);

}
}
_________________
Thanks and Best Regards,
Kyaw Kyaw.

PCM programmer · Joined: 06 Sep 2003 Posts: 21708

You're not following my sample driver. You are inventing stuff.
I give up.

Kyaw Kyaw · Joined: 17 Dec 2006 Posts: 15 Location: Singapore

i also tried with ur program also. but still cannot get the result. that why i tried to use this program.

thanks & best regards,
kyaw kyaw.
_________________
Thanks and Best Regards,
Kyaw Kyaw.

Kyaw Kyaw · Joined: 17 Dec 2006 Posts: 15 Location: Singapore

Hi all, Today i tried to see the sda and scl pin outputs with scope and i found that it is working according to the timing diagram of ISL 29001 but still got FFFF hex and it was not included the 30 hex for writing to ISL29001. I tested with PWM Programmer's codes. It should be the ISL29001's defect. Thanks for helping me to solving my difficulties. Smile

_________________
Thanks and Best Regards,
Kyaw Kyaw.