Hello the prodct description is contradictory. I read at numerous places all Pixy digital IO is 3.3 v.
However in the wiki, it says:
_" The I2C interface operates as an I2C slave and requires polling.
There are weak 4.7K pullups to 5V on SDA and SCL signals, via R14 and R15."
_
I want to use only 3.3v as 5v would blow my GPIO pins. However it says SCL and SDA are tied to 5v … any ideas how can I change it to 3.3v ?
Hello Gaurav,
Pixy’s I/O ports are 3.3V (correct) and the I2C interface uses pullup resistors to 5V (also correct). Pixy’s digital inputs are also 5V tolerant. The I2C pullup resistors have been changed to 80K for hardware version 1.3A so they are very weak. What do you want to interface to (what controller or processor?) It is very likely that your controller or processor can handle the low current (on the order of 10uA) the pullups will source. But you can always remove R14 and R15 if you are concerned.
Hope this helps!
Edward
Hello Edward.
Thanks for the info. I am planning to use pixy with de0 nano altera FPGA board. Hopefully things work !
Thanks
Gaurav
Hi Gaurav,
I’ve worked with the Altera pats some. All of them I encountered had clamping diodes. This might be too bold to state outright, but I think all modern CMOS parts have clamping diodes to protect against overvoltage.
Hope it works out for you!
Edward