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I2C Queries

Long story short, I am using the Lego firmware for a non-lego system, so I am making my own drivers. Also, I am not sure which forum to post this in. When sending a signature query, the documentation says to send a query to a register 0x51-0x57, and that no more data is needed. What do I need to send to a register in order for it to count as a query? Do I need to send a 0, a 255, or does it accept anything?

Hello KJ,
You just need to send (for example) 0x51 (and nothing else and then start reading) if you want to get the largest detected object from signature 1.

Hope this helps!

Edward

I’m new to this, so sorry if this question is stupid, but what do I send that to? Do I send 0x51 to the register 0x51 on the device?

Edit: I now see some code which makes it seem that the Lego firmware does not use registers either. Is there any firmware that does? And additionally, does using register 0x00 read the values from the camera?

Hello KJ,
You essentially send a 0x51 byte to Pixy over I2C and start reading over I2C. I2C sometimes uses “registers”. These are essentially numbers that are implemented in firmware that do specific things – read (return) data or write data.

Hope this helps!

Edward