Re: [Flashforth-devel] Problems with I2C

[Peter J. <pe...@me...>]

To me, this sounds like the slave is not acknowledging, the PIC is 
waiting and the watch-dog timer expires.  Hence, the reboot.  Can you 
put an oscilloscope or logic analyser on the I2C lines to see if the 
slave is actually acknowledging the address byte on the 9th clock?
Peter J.


On 27/03/14 17:14, Thomas Buschhardt wrote:
> Hallo,
>
> I've problems to get my I2C-Master running. Here is my config:
>
> PIC18F2620
> Clock 8MHz
> OSC = INTIO67
> TemperaturSensor: DS1621
>
> Here is what I do:
> I connect the sensor SDA with PIC.Pin 15 and the SCL with PIC.PIN 14. 
> I tested different pullup-resistors on both lines (10K - 3.3K - 1.8K).
> I tested different sensor-addresses: 1001 000 (all AddressPINs GND) 
> and 1001 100 (A2 with 10K resisitor to 5V, A1-A0 GND)
>
> I import i2c_base.txt (\flashforth\PIC18\forth) and use the example 
> from ff-tutorial-guide.pdf.
>
> When I run the "init_(tempsensor)" the PIC reboot. I find out that 
> ":i2cinit" come back with "OK", but when I run ":i2cws" (+ slaveaddr) 
> the PIC reboot.
>
> I know the Sensors are ok, because I tested them in a selfmade heating 
> control (since 2010 - written in Ruby - sorry :-)) and I have ca. 10 
> of these IC's there.
>
> If I can send any more informations please drop a mail :-)
>
> Thank you
> Thomas
>