I2C write - value too big

[Acetronics2]

Hi,

I wonder the '675 was running @ 4Mhz , the '88 is running @ 8Mhz ... which is the limit for using " I2C SLOW" ...

Did you try that DEFINE ???

Just an idea ...
Alain

[mister_e]

Not a problem for the 24LC512 unless the pull-up resistor are way to high... it can run up to 400KHz, 1MHz for FC version.

But there's few mistakes in the code.... sure i missed a few

[ruijc]

Hello sayzer, Mister-e and Acetronics

1. You have two "goto" s one after the other. When the first one runs, the second one will not run!

this is true. I sampled this section from the hole code to test your help but there are some " ' " missing there.

However, removing the missing links and compiling errors the final result is the same.

Code:

I2CREAD SDA,SCL,CTW,ADDR.highbyte,addr.lowbyte,[tempe]

Why do you split addr in 2 ?
Code:

I2CREAD SDA,SCL,CTW,ADDR,[tempe]

This have to be changed in ALL I2CREAD AND I2CWRITE lines

This is my biggest problem. What you suggested was my first written code and it didnt worked.

This was my problem in the past and resolved with the help of Skimask.
(see post...)
http://www.picbasic.co.uk/forum/showthread.php?t=8153

Frankly,i didnt understood then as i still dont now, but it worked.

The problem now is that it's not returning good values after the 127 mark and i believe that it's related with 1111111 going to 10000000 since that i read nothing but 000.x from there.

( see attached pic )

.

[ruijc]

Well, i think i just fixed one problem and found a new one

I have sucessfuly use the code " I2CREAD SDA,SCL,CTW,ADDR,[tempe] ".

After several changes i tryed Mister-e's suggestion and removed the OSCTUNE=0 line.

It doesnt make sense to me ( or does it ? ), but it's working this way now.

The new problem that i found is that while debugging i found out that the problem related with getting low values passed the 120'ich mark IS NOT related with the eeprom/low-highbytes.

I got a variable resistor to simulate the LM35 and was changing the value while recording, and i could see that the value captured dropped after the conversion and before recording to the eeprom.

this is the capture while increasing the variable resistor

111,3
111,3
111,8
112,3
112,3
112,7
112,7
113,2
113,7
114,2
114,7
115,2
115,7
116,2
117,6
118,1
118,6
118,6
118,6
118,6
119,1
121
121,5
122
122,5
122,5
122,5
122,5
0,4
0,9
0,4
0,9
0,4
0,9
0,4
0,9
0,4
0,9

now i'm lost

.

[Acetronics2]

Hi, Ruicj

Can you tell us how you get those values :

( 122.5 is NOT a PbP value ...)

- Input value range ( volts ? ) / ref voltage
- Math used ( in PbP )
- Values you want to to output

It's "not so clear" ...

Alain

PS : ANSEL doesn't match the ADCIN PORT !!! Check it !!!

[ruijc]

Hello Acetronics,

these values i get from:

FOR ADDR=st TO ed
     
   		adcin temp,va
 
tempe=(va*/5000 )>>2

        toggle red
        toggle green
        pause   418    ' calibration to get  1200  readings  ( 2 per second ) in 10 minutes   - 
        debug " recorded value: ", dec tempe," position  ", dec ADDR, 13,10

the debug line gave these values after the adcin conversion.
I'm colecting the voltage directly from the variable resistor which is simulating the voltage from a LM35 ( 0,2v - 1,5V )
I'm not using any reference value, just VDD and VSS( i know...it's lame...but i'm not looking for the best resolution for now )

.

[Acetronics2]

seen it ???

: ANSEL doesn't match the ADCIN PORT !!! Check it !!!

ANSEL select A1 and A2
ADCIN select A0 ...

Alain

[ruijc]

Acetronics,

You are right !!! Thank you ( and the rest of the guys for the help )

This was set when i was playing with several sensors

But how can it be ?? If i have the ANSEL with a different channel, how can i get values on channel A0 ??

This is why i didnt see it