[lm-sensors] Random values with pcf8591 chip driver (Now as a new

[lm-sensors] Random values with pcf8591 chip driver (Now as a new

[Mirko Buholzer]

I am using a pcf8591 chip on a linux 2.6.8 Kernel. The Adapter Driver is 
the scx200_i2c. When I do a sensors command I get random values on each 
input channel. Channel 1/2/3 are all set to 0V.

voyage:~# sensors
pcf8591-i2c-1-49
Adapter: NatSemi SCx200 I2C
Chan. 0:    1.28 V
Chan. 1:    1.28 V
Chan. 2:    1.28 V
Chan. 3:    1.28 V
Output:     0.00 V (enabled)

Does anyone have any hints or tricks on how I can proceed with debugging 
and error correction? Or is this a known problem?

Thanks and best Regards,
Mirko

-- 

Mirko Buholzer
mirko@buholzer.com

[lm-sensors] Random values with pcf8591 chip driver (Now as a new

[Mirko Buholzer]

I load the modules as follows:

modprobe scx200_i2c scl4 sda5
modprobe pcf8591 input_mode=0

Mirko Buholzer wrote:

> I am using a pcf8591 chip on a linux 2.6.8 Kernel. The Adapter Driver 
> is the scx200_i2c. When I do a sensors command I get random values on 
> each input channel. Channel 1/2/3 are all set to 0V.
>
> voyage:~# sensors
> pcf8591-i2c-1-49
> Adapter: NatSemi SCx200 I2C
> Chan. 0:    1.28 V
> Chan. 1:    1.28 V
> Chan. 2:    1.28 V
> Chan. 3:    1.28 V
> Output:     0.00 V (enabled)
>
> Does anyone have any hints or tricks on how I can proceed with 
> debugging and error correction? Or is this a known problem?
>
> Thanks and best Regards,
> Mirko
>

[lm-sensors] Random values with pcf8591 chip driver (Now as a new

[Jean Delvare]

Hi Mirko,

> I load the modules as follows:
> 
> modprobe scx200_i2c scl4 sda5
> modprobe pcf8591 input_mode=0

Do you have any other chip on that I2C bus? Maybe the bus isn't working
at all and it's not the PCF8591 fault. How did you come to these values
for scl and sda?

-- 
Jean Delvare

[lm-sensors] Random values with pcf8591 chip driver (Now as a

[Mirko Buholzer]

The pcf8591 is the only chip. When I do a "i2cdetect 1" and change the 
hardware address from 100 to 000 you can see the output below (The UU 
value comes from the loaded chip driver), so for me it looks like a 
detected chip?

100:
voyage:~# i2cdetect 1
WARNING! This program can confuse your I2C bus, cause data loss and worse!
I will probe file /dev/i2c-1.
I will probe address range 0x03-0x77.
Continue? [Y/n]
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          XX XX XX XX XX XX XX XX XX XX XX XX XX
10: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX
20: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX
30: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX
40: XX XX XX XX XX XX XX XX XX UU XX XX XX XX XX XX
50: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX
60: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX
70: XX XX XX XX XX XX XX XX


000:
voyage:~# i2cdetect 1
WARNING! This program can confuse your I2C bus, cause data loss and worse!
I will probe file /dev/i2c-1.
I will probe address range 0x03-0x77.
Continue? [Y/n]
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          XX XX XX XX XX XX XX XX XX XX XX XX XX
10: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX
20: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX
30: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX
40: XX XX XX XX XX XX XX XX 48 UU XX XX XX XX XX XX
50: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX
60: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX
70: XX XX XX XX XX XX XX XX


Thanks for your feedback!
Regards Mirko

Jean Delvare wrote:

>Hi Mirko,
>
>  
>
>>I load the modules as follows:
>>
>>modprobe scx200_i2c scl4 sda5
>>modprobe pcf8591 input_mode=0
>>    
>>
>
>Do you have any other chip on that I2C bus? Maybe the bus isn't working
>at all and it's not the PCF8591 fault. How did you come to these values
>for scl and sda?
>
>  
>