ESPUSB - Here you can chat about the specifics of the hardware involved

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By RichardS
#52798 Just wondering? I know it works with I/O on AVR, but I think people would like to know the details of this...

RichardS
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By cnlohr
#52819 They are kind of differential. During normal data they are differential, but end-of-packet is specified by both lines going low for two time slices.

The two wires are directly connected to two adjacent GPIOs (in the low-speed mechanism). Only thing in addition is I wired a 1.5k resistor between d- and 3.3v.

*EDIT* Supposedly, there's also supposed to be resistors in line with D+/D- -- though for short runs I don't think it's needed.
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By RichardS
#52846 So if its differential the voltage swings must be large enought to cause 0 and 1 transistions on the I/O, if the 2 differential pairs hung out a say Vcc/2 and just swung north and south of one another I can not see how the I/O would "see" that.....

RichardS