search

webusb / arduino

WebUSB demos running on Arduino (and compatible) hardware.
580 stars 154 forks source link

Transfer more than 64ytes #105

Closed jeremypy972 closed 2 weeks ago

jeremypy972 commented 1 month ago

Hello, I'm trying to transfer JSON between Arduino and Chrome. But the data is divided in 64bytes chunks. Sounds that Chrome buffer is 4096.

I tired to change the value from 65 to 4096 in transferIn line in serial.js, but it has no effect. Is it something we can configure somewhere ?

Jérémy

jeremypy972 commented 1 month ago

Just after connect, received bytes is more than 64 (75 for instance), but on the second transferin I get data in two times (64+11).

reillyeon commented 4 weeks ago

There are two limits, the packet size and the transfer size. The value you pass to transferIn() controls the size of the buffer Chrome allocates for the transfer that can be filled by the device. The device sets the packet size in its USB descriptors and can fill that transfer buffer one packet at a time. The device controls when the transfer is "complete" and so it's possible that it only ever responds to a transfer request with 64 bytes.

jeremypy972 commented 2 weeks ago

Thanks