Sensoray 311 User Manual
Page 8
88
GPIO inputs (JP1)
Pin
Signal
Pin
Signal
1
GPI0
2
LVDD
3
GPINT
4
GPO3
5
GND
6
GND
7
+12V
8
+5V
9
GPO2
10
GPI3
11
GPI2
12
GPI1
13
GPO0
14
GPO1
Notes:
1. GPO0-GPO3 – TTL outputs.
2. GPI1-3 – CMOS inputs.
3. GPI0, GPINT – optocoupled.
Optocoupled GPIO signals
Two of the GPIO signals (GPI0 and GPINT) are optocoupled. The following figures illustrate the use of
optocoupled inputs.
For complete isolation the input should be connected as shown in Figure 1. Supply voltage for the optocoupler
LED is provided on LVDD (pin 2). If a 5 Volt supply is used, then R1 is not necessary, as the internal resistor R3
limits the current. If a higher voltage is used, then the value of R1 must be calculated to limit the current flowing
through the LED to approximately 15mA.
If complete isolation is not required, then the LED can be powered from the 5 Volt output, VDD (pin 8), as shown
in Figure 2. The input is then has to be pulled down to the 311’s digital ground, GND (pins 5 and 6).
For the details on how to use GPINT see the SX11 SDK Software Manual.