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speed and frame rate for each interface


#1

Hi all!
I have a pair of questions about Pixy’s Interfaces.
Which is the frame rate and the speed of each interface?
I read that Pixy sends block information to Arduino at 1 Mbits/second over SPI, for example, and the maximum baud rate is 230 Kbaud over UART, but what about I2C and analog and digital output?

Another question.
Is the UART flow control Hardware or Software?

Thanks


#2

Hello Elia,
Pixy functions as an I2C or SPI slave, which means that it doesn’t supply the clock (the master supplies the clock and determines the clock rate). However, Pixy will work with SPI clock rates up to 1 mbit/s. I2C can function up to 100 kbit/s, although it may be more depending on the cable length and the pullup resistors used. It’s difficult to estimate the rate of analog output. The UART has no flow control.

What are you trying to determine exactly? What would you like to do with Pixy?

Edward


#3

Hi Edward!
Ok, thanks for the answers.
I’ve made a mouse emulator with PIC microcontroller and Pixy for my master degree thesis.
Now I’m writing all the specs of Pixy and my supervisor wants that I describe all the Pixy interfaces and their rate and speed.
This information is not in Pixy porting guide so I had to ask you.

Thank you very much :slight_smile:


#4

what is the maximum baud rate for the Pixy 2 camera over UART?


#5

HI Elia,
I’ve heard of people using 921600 baud with decent success, although I haven’t tried it myself (for lack of a controller that supports that rate.) I would also imagine that the cable would need to be reasonably short.

I usually use 115200 baud and it works well.

Edward