nouvelle_adr
Posts: 3
Joined: Sat Dec 08, 2018 3:46 pm

i2cdetect doesn't catch ANY address (no device detection)

Sat Dec 08, 2018 3:49 pm

Hello,
I have ti046b1 chip (Serial I2C F-RAM) (Dell laser printer with almost dead toner cartridge)
I tried to read it with my raspberry Pi 3, so I connected SDA SCL VDD GND as shown in pictures, but when I run the command "i2cdetect -y 1" on my Raspberry it shows no device connected to I2C interface (empty) like that:

[email protected]:~ $ i2cdetect -y 1

0 1 2 3 4 5 6 7 8 9 a b c d e f

00: -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --

do you have any idea to solve that ?
- I tried by inverting SDA SLC connections
- I tried by pulling-up to 3.3V SDA and SCL with 10k resistors (as stated viewtopic.php?t=7664)

could you please help me to solve that ?

And to anticipate your first question : I checked all the connections for this wiring :)

Image
Image
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Last edited by nouvelle_adr on Sun Dec 09, 2018 2:21 pm, edited 1 time in total.

Andyroo
Posts: 689
Joined: Sat Jun 16, 2018 12:49 am

Re: i2cdetect doesn't catch ANY address (no device detection)

Sat Dec 08, 2018 5:49 pm

When you say ' I tried by inverting SDA SLC connections' do you mean swapping them or using a level inverter?

Some of these chips use a 10-bit addressing scheme not an 8-bit one (for security) so you may need an external reader :twisted:
Need Pi spray - these things are breeding in my house...

nouvelle_adr
Posts: 3
Joined: Sat Dec 08, 2018 3:46 pm

Re: i2cdetect doesn't catch ANY address (no device detection)

Sat Dec 08, 2018 8:05 pm

Andyroo wrote:
Sat Dec 08, 2018 5:49 pm
When you say ' I tried by inverting SDA SLC connections' do you mean swapping them or using a level inverter?

Some of these chips use a 10-bit addressing scheme not an 8-bit one (for security) so you may need an external reader :twisted:
the "inverting" that I did is a simple swapping :)

Thank you for your assumption on probable 10-bits addressing, but here https://www.eevblog.com/forum/projects/ ... p-ti046b1/there are some people who have managed to read/write on this TI chip (with Arduino)

Andyroo
Posts: 689
Joined: Sat Jun 16, 2018 12:49 am

Re: i2cdetect doesn't catch ANY address (no device detection)

Sat Dec 08, 2018 11:08 pm

I would be tempted to buy blanks from Alibaba to be honest :lol: That link seems to be a Lexmark chip and not a Dell - they may be the same but I'm not putting any money on it. (Hate Dell printers)

You could try altering the clock speed on the I2C bus as some chips support:
  • 100 KHz
  • 200 KHz
  • 400 KHz
  • 800 KHz
  • 1.2 MHz

I think that you need to add the speed into /etc/modprobe.d along the lines of

Code: Select all

options i2c_bcm2708 baudrate=xxx
or at the command line:

Code: Select all

i2c-bcm2708 baudrate=xxx
i2c-dev
or

Code: Select all

modprobe -r i2c_bcm2708
modprobe i2c_bcm2708 baudrate=xxx
Problem is there is lots of contradictory info on this and I only have one I2C device handy and its working at the mo :lol:

I'm also interested in P$4 - hate lines floating - wonder if its a chip select - does it trace out anywhere?
Need Pi spray - these things are breeding in my house...

nouvelle_adr
Posts: 3
Joined: Sat Dec 08, 2018 3:46 pm

Re: i2cdetect doesn't catch ANY address (no device detection)

Sun Dec 09, 2018 2:19 pm

Andyroo wrote:
Sat Dec 08, 2018 11:08 pm
I would be tempted to buy blanks from Alibaba to be honest :lol: That link seems to be a Lexmark chip and not a Dell - they may be the same but I'm not putting any money on it. (Hate Dell printers)

You could try altering the clock speed on the I2C bus as some chips support:
  • 100 KHz
  • 200 KHz
  • 400 KHz
  • 800 KHz
  • 1.2 MHz

I think that you need to add the speed into /etc/modprobe.d along the lines of

Code: Select all

options i2c_bcm2708 baudrate=xxx
or at the command line:

Code: Select all

i2c-bcm2708 baudrate=xxx
i2c-dev
or

Code: Select all

modprobe -r i2c_bcm2708
modprobe i2c_bcm2708 baudrate=xxx
Problem is there is lots of contradictory info on this and I only have one I2C device handy and its working at the mo :lol:

I'm also interested in P$4 - hate lines floating - wonder if its a chip select - does it trace out anywhere?
Test done with these frequencies, and nothing happened :(

but look:
you gave me an idea, so I connected the scope while the chip is inside the printer in order to see what is the communication frequency, it gives me that (approximately I guess something like 360KHZ):
Image

What do you think ?

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