Implement communication from arduino to Pi
rwilbur opened this issue · 4 comments
We need to figure out if this is going to use UART or SPI
I'm wondering which one is more noise redundant and whether ground voltage differences could pose an issue. Maybe not given cable length. I was thinking of a differential link (RS485/LVDS) but this would increase the complexity a bit and the number of components required. Maybe UART could give us the necessary speed, do you know how fast the UART can go on this Arduino?
Looking at the clock rate and from what people have said online it appears to be capable of 2Mbps. I agree the differential UART link would be nice to have because of the robustness to noise. I have used RS232 in quite noisy environments and have never had noise issues with it so in practice it might be perfectly acceptable. I think the fewer the parts the better.
I presume the Arduino only has a UART output (0 to 3.3V) instead of +-12V? To add RS232, we may need to add an extra module anyway, a MAX232 perhaps? Maybe these come in premade modules for rpi / arduino.
I meant 3.3v when I said 232 but that is incorrect. I think the 3.3v UART would probably be fine. The UART on the PI is also 3.3v so they should play nicely together. If these 2 devices are super close together we can probably do a good job keeping noise down by just having a super connection.