Date: Mon, 20 Apr 2015 21:48:55 +0200 From: Bernd Walter <ticso@cicely7.cicely.de> To: freebsd-usb@freebsd.org Cc: Bernd Walter <ticso@cicely7.cicely.de> Subject: Strange problems with CH340G (uchcom) Message-ID: <20150420194855.GA29418@cicely7.cicely.de>
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I tried to flash an ESP8266 with the onboard CH340. The same board works fine when I use a CP2102 instead of the CH340. Flashing requires a python tool, which sends a SLIP encoded request and expects a SLIP encoded response with 115200@8n1. The read function however times out receiving the response without getting a single byte, even if I add a high delay between sending and reading. The strange thing is that I can see a valid response on a scope just a few µs after the request completes, while the receiver don't even see the first byte. If however I physically loopback the CH340 it receives it's own request just fine. Two CH340 xconnected work fine too. Same when I xconnect a CH340 and a CP2102. Now I'm completely out of ideas, why the python tool has problems to see the response data with the CH340. -- B.Walter <bernd@bwct.de> http://www.bwct.de Modbus/TCP Ethernet I/O Baugruppen, ARM basierte FreeBSD Rechner uvm.
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