IRgaskiT
Application Note 1
Things to do With your IRgaskiT No.1
With just a few readily available components you can make your
IRgaskiT
into a USB device to use with any USB enabled PC.
First you will need an IRgaskiT processor board with a
suitable sensor head, a USB to 3.3V TTL serial converter, (we
used the FTDI TTL-232-3V3 Cable see
http://www.ftdichip.com/Products/EvaluationKits/TTL-232R.htm)
some ribbon cable and two micromatch plugs (one 6 way one 16
way). We used a pre-made 16 way cable and a free plug (ours were
from Farnell Part No. 1056226 and 149068).
If you wish to copy our cable in order to make the USB adapter
you will need to cut the 16 way Micromatch cable in half , then
cut the ribbon close to the connector from the pin #1 end to
wire #12. Wires #5,6,7,8,9 and 10 are then separated from the
rest of the cable and the 6 way micromatch plug fitted at a
suitable distance along the wires, with what was wire #10
connected to pin #1 on the 6 way micromatch. For
neatness wires #1 to #4 may be removed completely and wire #11
should be removed to about 1 CM beyond the 6 way plug.
Wires #1, 2 and 3 from the 6 way micromatch (originally wires
#10, 9 and 8 on the 16 way micromatch) are the 5V input and in
our case are connected to the Red (#3) wire on the FTDI cable.
Wires #4,5 and 6 from the 6 way micromatch (originally
wires #7,6 and 5 on the 16 way micromatch) and wire #16 from the
16 way micromatch are the Ground and in our case are connected
to the black wire (#1) on the FTDI cable.
Wire #15 from the 16 way micromatch is the Rx data and in our
case connected to the Orange wire (#4 TXD) on the FTDI cable and
finally wire #14 is Tx data and in our case is connected to the
yellow wire (#5 TXD) on the FTDI cable (see Figure 1).
Figure 1 Wiring Diagram for our USB Cable
Once you have checked your cable the 6 way micromatch is
plugged into CN2 and the 16 way micromatch is plugged into CN1
on the IRgaskit Processor board.
You need to load any USB drivers for your USB to TTL
converter and Operating System (OS) (in our case we used the
setup executable driver for MS Windows from FTDI). Once this
is done you can plug your USB to TTL converter into your
computer and use either serial terminal software (such as
HyperTerminal supplied with MS Windows up to XP but not with Vista) or the IRgaskit (MS Windows) data logger available
from the Edinburgh Instruments web site to communicate with your
IRgaskiT.
For other Operating Systems there are usually serial terminal
emulators supplied with the OS or downloadable from the
internet. e.g. Minicom or Gtkterm for Linux and Quickterm for OS
X.
Figure 2 below shows our USB interface cable connected to
an IRgaskiT with a 10% CO2 head.
Figure
2
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