Using the GUI
Figure 20. EVM GUI Settings When Using On-Board Keys
5. Now press any of the keys and watch the various interrupts fire. The
Auto Read on /INT
checkbox can
be unclicked to view what occurs if the interrupt is not read after numerous key presses.
For more information on key press operation, refer to the datasheet (
).
7.4
Using the TS3A227E to Develop a Headset
If the EVM is being used to test/develop headset keys by a manufacturer, there are multiple ways to test
this:
Method One
If there is an existing headset that the manufacturer is looking to add keys to without changing the
microphone, insert the headset into audio jack J4. Place jumpers on J15 and J20 and remove the jumper
on J16. Enable key-press detection in the GUI and enable raw data mode. Enabling raw data mode shows
the exact detected resistance instead of the bin the resistor falls in.
Once setup, attach the parallel or resistor between the SLEEVE and RING2 pins, not between one of the
SLEEVE/RING2 pins and ground. The TS3A227E sees this drop in voltage on the MIC line and detects
the parallel resistance combination.
Method Two
Creating a new headset with a prototype microphone.
If the headset is in development and testing the key resistance values is needed, use the following
method:
1. Enable Manual Switch control
2. Set the S3 matrix so the ground and microphone are routed to the appropriate pin:
•
S3PS
→
MIC on SLEEVE
•
S3PR
→
MIC on RING2
•
S3GS
→
ground on SLEEVE
•
S3GR
→
ground on RING2
3. Turn on the appropriate GNDFET for the location of the ground pin.
4. Place jumpers on J15 and J20 and remove the jumper on J16.
17
SLVUAD9 – December 2014
TS3A227E EVM User's Guide
Copyright © 2014, Texas Instruments Incorporated