IQ Switch
®
ProxSense
®
Series
Copyright © Azoteq (Pty) Ltd 2022
IQS227-228BEV02 Evaluation Kit User Guide
Page
3
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10
All Rights Reserved
Revision 1.0
November 2022
After the device is powered through the ON/OFF slide switch, the device calibrates itself for the
main board setup. This normally takes less than a second.
3.2 Jumper placement
The placement of the jumper is very important and should by default connect the GND and PROX
pins to add extra ground to the system. This is especially important when operating from a battery
as the system does not have a very good ground reference and this will ensure correct operation.
The jumper can also be shifted to connect the CX
and PROX pins to increase the touch pad’s size
and reduce the ground in the system. This is advised against when running off batteries as the
system’s ground reference is too small to ensure correct operation and false Prox events will be
triggered when touching the ground pour areas on the board.
Figure 3.1 Jumper placement
•
When the jumper is connected on the PROX and GND pins, the 2 pads on each side of the
button are also connected to GND. This takes away some sensitivity, thus smaller
detection distance, but also less susceptible to noise that could couple into the system.
•
When the jumper is connected on the CX and PROX pins, the 2 pads on each side of the
button are also connected to the CX. This increases the sensitivity, thus bigger detection
distance, but also more susceptible to noise that could couple into the system.
3.3 Device operation
After power ON, touch the button with a finger and 2 LED’s should turn on as in Figure 3.2.
Figure 3.2 Standalone activation
The blue LED indicates a proximity event and the red LED a touch event. Evaluate the different
module boards to observe the difference in sensitivity between them.
If the LED’s do not turn on when touching the button, release the button or put the device on a
table and try again.
CX
PROX
GND
