I2c on BBB

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Niki
 
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I2c on BBB

Post by Niki »

I want to send and receive data with I2C2 (P9_19= I2C2 Clock, P9_20= I2C2 Data). The Adafruit IO Python Library (Justin Cooper) for Debian I have installed.

My programm in the Python Shell is:

>>>from Adafruit_I2C import Adafruit _I2C
>>>i2c = Adafruit_I2C(0x77)
>>>adress = 0x21
>>>i2c.write8(0x12, 0x22)
Error accessing 0x77: Check your I2C adress
-1

On P9_19 and P9_20 I have no Clock respectively Data output. Both stay on logical 1.

Please, can you help me and tell me what I have to do in order to make it work.

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adafruit_support_rick
 
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Re: I2c on BBB

Post by adafruit_support_rick »

what do you get from i2cdetect -y 1
Can you post the output? Is anything detected at 0x77?

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Niki
 
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Re: I2c on BBB

Post by Niki »

Thank you for helping me.
If I write i2cdetect -y 1 in the linux shell, it says "Error: Can`t use SMBUS Quick Write command on this bus"
I am sorry but I dont know what I have to do to detect on 0x77.
When I test with my Hp-Logic Probe on P9_19 or P9_20, there is always Logic 1.

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adafruit2
 
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Re: I2c on BBB

Post by adafruit2 »

are you running these as 'sudo' commands?

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Niki
 
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Re: I2c on BBB

Post by Niki »

There is no change using sudo command.

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