Quote:
Originally Posted by SiriusHardware
As I read it, DA52 has tried using a USB camera (post #156) and is suffering a lot of lag.
Historically speaking USB comms had to go through a bit of a bottleneck on the Pi since all USB traffic went through one narrow channel, or that was my understanding - That may have improved on the later models.
Imagine trying to initiate an action on the online connected MK14 and not seeing it respond for several seconds, it would be like trying to speak while listening to your own delayed voice.
The 'proper' cameras for the Pi seem to have their own exclusive highway over which to communicate with the Pi.
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That is largely true. Early Pi's used the USB channel for its ethernet link too, which meant they were sharing bandwitdth on a single hub.The newer Pi 4 has a faster USB interface (up to 10x!) with more channels but the concern still somewhat applies. The Pi has a "CSI-2" fast serial interface on most models (other than the compute modules). The version of the Pi camera for the Pi Zero is half the price of the one for the larger PI's but can be connected to them with an adapter cable as the size of the connector is different on the Zero, but the signals are the same. The big problem I saw for my application is the cable is rather short but that would not be a problem in other uses.
For this application, however you could set a USB camera to quite a low resolution (320 x 200) which is pretty fast and low lag.