Some questions regarding power distribution & serial communication

Project Discussion
1

Hey OpenMV forums,

I have some questions regarding a project I will be making soon. It includes the OpenMV cam, aswell as a slave Arduino nano for some additional tasks. The OpenMV board will communicate with the Arduino and tell it what to do. We are aware that the OpenMV microprocessors could be used as a substitute for an Arduino, though we still want to use it in this case.

  1. We will be using the Pan & Tilt shield to control two servos. Our question is: if we supply this shield using a (unregulated) 8 or 12-volt battery, would it power the OpenMV cam without having to add additional wiring or connections? And, can we somehow power the Arduino Nano aswell, using any of the connections on the shield? It’s safer to supply this Arduino with a 5V signal than with an unregulated battery voltage.

  2. Regarding the communication between Arduino and OpenMV, can this be easily done? Let’s say we want to tell the Arduino to control the movement of the car, to move either to the right or the left. As we’re not really experienced with communication between microprocessors, we would like to know whether this would take us a long time to figure out or if it’s a matter of a few hours of testing. Also, can the communication happen both ways? As in the Arduino also sending information back to the OpenMV. My apologies if this sounds like a rather stupid question, we’re just getting started with all of this.

  3. Perhaps related to #1), what is the extra (fourth) connection for on the P&T shield? The one next to S0, S1 and S2. Can this be used as an extra power source? It says something on the pinout image, though we don’t quite understand what it means.

I myself have a few years of experience with programming, and given that the machine vision part includes pre-made functions I should be able to figure that out rather quickly. So I do not foresee any trouble with that. It’s mostly the electrical part that we’re trying to figure out now.

Thanks in advance!

2

Yes there’s a 1A/5V regulator on that shield which powers the cam, servos and you can use the output to power the Arduino.

We have examples showing I2C, UART and SPI communications between the cam and Arduino, UART should be relatively easy to use.

No, it’s for regulated 5V input, instead of the battery connector.

3

Great! That’s all we needed to know. I found the UART example and I think I’ll get to it as soon as next week, to try and figure it out. Seems pretty straight forward. I now understand what the product page meant with the power distribution on the P&T shield, thanks for clearing that up. This answered all my questions.