asante porter

Connects FTDI usb cable to the controller module's UART.

udev rules

• http://www.reactivated.net/writing_udev_rules.html#basic
• https://wiki.archlinux.org/index.php/udev
• # udevadm monitor --environment --udev --kernel - Prints items that can be matched using ENV{NAME}=="..." syntax
• sudo modprobe ftdi_sio vendor=0x0403 product=0x7f38 - magic incantation to create a ttyUSB0 device
• udevadm info --attribute-walk --name /dev/ttyUSB0 - prints items that can be included in rules.
• udevadm info --attribute-walk --path /devices/pci0000:00/0000:00:11.0/0000:02:00.0/usb2/2-2/2-2.2 - prints items that can be included in rules.
• but udev runs one entry at a time, rules cannot match across entries, except by passing messages via environment variables?
• Testing indicates that certain environment variables persist across more consistently than the device attributes. Simplest solution is to always test for environment variables along with the SUBSYSTEM and perhaps KERNEL.

udev rules

# udev detects an ftdi device, (usable with libfdti I suppose)
# inserting  ftdio_sio module with our vendor's parameters creates a ttyUSB0
# udev can only match one entry at a time, but this triggers additional add entries.
ACTION=="add", SUBSYSTEM=="usb",                  \
  ATTR{idVendor}=="0403", ATTR{idProduct}=="7f38", \
  RUN+="/sbin/modprobe ftdi_sio vendor=0x0403 product=0x7f38"

# create a symlink to the ttyUSB device created automatically above
# rename to AsantePorterX where X is each connected cable/cradle starting at
# zero.
ACTION=="add",                                       \
  ENV{DEVNAME}=="ttyUSB[0-9]",                        \
  ENV{ID_MODEL_ID}=="7f38",                            \
  ENV{ID_VENDOR_ID}=="0403",                            \
  PROGRAM+="/usr/local/bin/asante-porter-name.sh %k %n", \
  SYMLINK+="%c"

# clean up, ftdi_sio can only be used once at a time
# this allows other applications to re-use ftdi_sio
ACTION=="remove",         \
  SUBSYSTEM=="usb",        \
  ENV{ID_MODEL_ID}=="7f38", \
  ENV{ID_VENDOR_ID}=="0403", \
  RUN+="/sbin/modprobe -r ftdi_sio"

Creates a /dev/ttyUSB.AsantePorter0 device when one cradle is plugged in.

When the controller is connected to the cradle, the beacon starts at 9600 baud:

$ npm install
bewest@paragon:~/src/ftdi-snap$ node index.js 
Howdy let's talk to an insulin pump!
opened {}
beacon? 4 <Buffer 7e 05 00 00>
beacon? 2 <Buffer 1f 8f>
beacon? 3 <Buffer 7e 05 00>
beacon? 1 <Buffer 00>
beacon? 1 <Buffer 1f>
beacon? 1 <Buffer 8f>
beacon? 2 <Buffer 7e 05>
beacon? 1 <Buffer 00>
beacon? 1 <Buffer 00>
beacon? 2 <Buffer 1f 8f>
beacon? 1 <Buffer 7e>
beacon? 1 <Buffer 05>
beacon? 1 <Buffer 00>
beacon? 1 <Buffer 00>
beacon? 1 <Buffer 1f>
beacon? 1 <Buffer 8f>
^Cbewest@paragon:~/src/ftdi-snap$ 

Do the beacon dance.