# HG changeset patch
# User Adam Novak <interfect@gmail.com>
# Date 1477543220 25200
#      Wed Oct 26 21:40:20 2016 -0700
# Node ID 774834381fea0cb89e88058b70ffa48243032077
# Parent  cc28502a220f297e56fa9d99e7ea74480e1cd15f
[uv5r] Work around low DTR on pl2303 chips on modern Ubuntu. Fixes #4165

This makes the UV5R driver explicitly set DTR to 1 and wait a bit for the radio
to stop trying to transmit and pay attention. DTR is defaulting to 0 when the
port is closed on Ubuntu 16.04 with the stock pl2303-based programming cable
that comes with the UV-82, and a low DTR activates the push-to-talk switch, at
least on the UV82. The radio needs a little time to come out of transmit mode
before it is ready to talk with CHIRP.

diff -r cc28502a220f -r 774834381fea chirp/drivers/uv5r.py
--- a/chirp/drivers/uv5r.py	Sun Oct 16 16:55:56 2016 -0700
+++ b/chirp/drivers/uv5r.py	Wed Oct 26 21:40:20 2016 -0700
@@ -398,6 +398,16 @@
 def _do_ident(radio, magic):
     serial = radio.pipe
     serial.timeout = 1
+    # Newer pl2303 drivers in Ubuntu are defaulting DTR to low, but that makes
+    # the radio transmit instead of talking to the computer. We need DTR to be
+    # high. See <http://askubuntu.com/a/469485/170317>
+    LOG.info("Set DTR")
+    # This is redundant since currently pyserial defaults DTR to true, and no
+    # other code changes it.
+    serial.dtr = True
+    # This is the actual fix: the radio needs a chance to respond to DTR coming
+    # high when the port opens.
+    time.sleep(1)
 
     LOG.info("Sending Magic: %s" % util.hexprint(magic))
     for byte in magic: