AN113
Rev 1.0 | Page 12/34
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In this scheme, the Tx module repeat transmission in every 3 seconds, and in each transmission, 6 predefined packets are
sent out. After CMT2250A-EM received the packets successfully, LED1-3 will be turned on at the same time for 500ms and
turned back to off. LED4 is unused in this scheme.
Beside the periodic transmission which is done automatically, the user can press the K1-K3 to send out the packets manually,
and the CMT2250A-EM responses to the transmission as usual. K4-K6 is unused in this scheme.
A few key parameters settings in this application scheme are:
Frequency
= 433.92 MHz
Symbol Rate
= 4.8 ksps
Encoder
= 1920
Push Button Setting = Normal, 5 buttons
Periodic Time
= 3 seconds
Study Function
= on
Study Button
= Pin9 (K3)
Notes:
1.
Please refer to the “AN112 CMT2150A Configuration Guideline” for the introduction of Normal mode of the push button
setting and the 1920 encoding format.
2.
The study function is enabled in this scheme, while the Sync ID on both of the Tx and Rx side are set to be the same by
default. In order to experience the study function, the user should set the Sync ID to the different values before burning
the configurations to the Tx and Rx devices. Pin9 (K3) is assigned as the study button in Periodic Tx scheme.
2.4 PWM
In the PWM scheme, the user can use the push buttons on the CMT2150A-EM to perform dimming control on the LED on the
CMT2251A-EM by the PWM signals generated by CMT2251A. The brightness of the LED changes with the duty cycle of the
PWM signal. The push buttons are shown and described in the figure/table below:
Figure 13. EMs Used to Experience PWM Scheme
