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Author Topic: USB-I2C converter - Cypress CY8C9560A  (Read 2619 times)


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USB-I2C converter - Cypress CY8C9560A
« on: October 06, 2017, 09:33:41 AM »

Good Morning,
I am using the CY8C9560A module from Cypress and I am trying to communicate with it through I2C. Using the Arduino SDA and SCL works without any problems, but when I try to use the USB-I2C(http://www.robot-electronics.co.uk/htm/usb_i2c_tech.htm) and USB-ISS(https://www.robot-electronics.co.uk/htm/usb_iss_tech.htm) converters and I get no response. I know it only supports I2C standard (100Khz), anyway I set the USB-ISS to 100Khz but without success. Is something missing? For example some kind of configuration. Has anyone ever come across this problem?
I am trying to send the following commands to address 0x40 (using Arduino is 0x20):
To select port 0:
55 40 18 01 00
To set the port as output:
55 40 1C 01 00
Enable Outputs Alternately:
55 40 08 01 AA
But no luck.
Sending equivalent commands through Arduino works fine:
20 18 00
20 1C 00
20 08 AA
Thank you so much.
Júlio Ferreira

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Re: USB-I2C converter - Cypress CY8C9560A
« Reply #1 on: October 06, 2017, 04:19:38 PM »

Hello Júlio,

We have not used these adapters ourselves unfortunately, but hopefully some of the other forum members can help.

One thing we did notice is that the 5 bytes of the command need to be sent together and so please check that your PC application does this without gaps between.

Best Regards,
FTDI Community