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[solved] Stepper driver over I2C not recognized

Posted: Fri Sep 05, 2014 11:26 pm
by raspmz
Hi,

I'm new to the I2C programming.
I bought this stepper driver module (http://www.elv.de/output/controller.asp ... ail2=30930)

I then followed the instructions to enable i2c on my raspberry. (https://learn.adafruit.com/adafruits-ra ... guring-i2c)
This seems to work as I can get the address of another i2c device by using i2cdetect -y 1

But if I only connect the stepper driver, no address is found by i2cdetect.
Does anybody have experiences with this stepper driver?

Many thanks in advance!

Re: Stepper driver over I2C not recognized

Posted: Sat Sep 06, 2014 7:52 am
by joan
That looks like a serious piece of kit.

How are you connecting it to the Pi? Does it need jumpers on the board to set its address?

Re: Stepper driver over I2C not recognized

Posted: Sat Sep 06, 2014 1:10 pm
by raspmz
I used 2 wires to connect it to the scl and sca (3 and 5) port of the pi.
There is a jumper to set to address to 192 or 194.
If i use my windows i2c to usb tool it is possible to control the driver, but my pi does not show any connected device if i attach it to it.

Re: Stepper driver over I2C not recognized

Posted: Sat Sep 06, 2014 1:17 pm
by hansotten
raspmz wrote:I used 2 wires to connect it to the scl and sca (3 and 5) port of the pi.
There is a jumper to set to address to 192 or 194.
If i use my windows i2c to usb tool it is possible to control the driver, but my pi does not show any connected device if i attach it to it.
The RPIi is a 3.3V device, your device 5V. What pull up resistors are attached? The RPi has pullups, your device may or may not have pull ups. To strong pull ups are dangerous to the RPi btw. Bidirectional level convertors exist for I2C and also may have (optional) pullup resitors.

With the USB I2C device its all 5 V and possible stronger pullups?

Re: Stepper driver over I2C not recognized

Posted: Sat Sep 06, 2014 1:19 pm
by joan
You also need to connect the ground wire between the Pi and the device (and the power if you are powering it from the Pi).

Re: Stepper driver over I2C not recognized

Posted: Sat Sep 06, 2014 7:37 pm
by raspmz
I know about the ground, i only forgott to mention that :D
My device is powered by an external powersupply as my stepper needs 10V.

Thx hansotten, i haven't thought about the 3.3 V :?

Re: Stepper driver over I2C not recognized

Posted: Sat Sep 06, 2014 8:10 pm
by raspmz
The RPIi is a 3.3V device, your device 5V. What pull up resistors are attached? The RPi has pullups, your device may or may not have pull ups. To strong pull ups are dangerous to the RPi btw. Bidirectional level convertors exist for I2C and also may have (optional) pullup resitors.

With the USB I2C device its all 5 V and possible stronger pullups?
thx hansotten, this pointed me in the right direction. The iSMT driver module uses 5V pullups.

Re: Stepper driver over I2C not recognized

Posted: Wed Sep 17, 2014 8:15 pm
by raspmz
Thanks for your help. It is working now. I needed a level shifter and some pullup resistors for the decice.