Matrix Orbital GLK19264-7T-1U - Manual (Page 15)

Figure 16: Serial Header
2.4 Protocol Select Jumpers
The Protocol Select Jumpers, pictured below in Figure 17, provide the means necessary to toggle the
display module between RS-232, TTL and I 2 C protocols. As a default for the Non-USB module, the jumpers
are set to RS-232 mode with zero ohm resistors on the 232 jumpers. In order to place the display module in
I
2 C mode you must first remove the zero ohm resistors from the 232 jumpers and then solder the resistors
on to the I 2 C jumpers, or bridge solder across the pads. The display will now be in I 2 C mode and have a
default slave address of 0x50 unless the I 2 C address has been changed. Similarly, in order to change the
display to TTL mode, simply remove the zero ohm resistors from the 232 or I 2 C jumpers and solder them
to the TTL jumpers. Although RS-232, USB, TTL and I 2 C are present, only 232/TTL/I 2 C are for use in the
Non-USB module. For the USB module operation the USB jumpers must be in place. There are three, one
is for power. If you wish to power it up from a non-USB source, you must remove one of the jumpers. The
jumper to remove is the rightmost USB jumper as seen if Figure 18.
Figure 17: Protocol-Select-Jumpers for GLK19264-7T-1U Non-USB
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