USER MANUAL
STM 550 / EMSI
–
ENOCEAN MULTISENSOR FOR IOT APPLICATIONS
© 2020 EnOcean | www.enocean.com F-710-017, V1.0
STM 550 / EMSI User Manual | v1.3 | September 2020 | Page 27/97
4.1
LED
STM 550 contains an indication LED used to provide user feedback. By default, the LED will
blink shortly whenever a telegram is transmitted. This indication can be disabled using the
LED_MODE register of the NFC interface as described in chapter 9.5.10. In addition to that,
the LED provides a response to LRN button inputs as described below.
4.2
LRN button
Most STM 550 device parameters can be configured using the NFC interface as described in
chapter 9. Some of the most common parameters or states can additionally be configured
using the LRN button. Table 4 below lists those LRN button actions with the corresponding
STM 550 response and LED feedback.
Type
LRN Button Action
STM 550 Response
LED Feedback
1 x
Short
< 1s Press
Exit from Sleep Mode
Send Learn Telegram
Success: 1 short blink
Error: No feedback
2 x
Short
< 1s Press,
Start Function Test
(End after 2 min or upon
any button press)
Transmit sensor status
with highest possible update
rate
< 1s Release,
< 1s Press
3 x
Short
< 1s Press,
Toggle LED indication
LED enabled: 2 short blinks
LED disabled: No feedback
< 1s Release,
< 1s Press,
< 1s Release,
< 1s Press
4 x
Short
< 1s Press,
Start Acceleration Test
Start of test: 4 short blinks
During test: 1 short blink
whenever acceleration
above threshold is detected
< 1s Release,
< 1s Press,
< 1s Release,
< 1s Press
< 1s Release,
< 1s Press
1 x
Long
3s < Press < 5s
Enter Sleep Mode
(Disable LED and Radio)
Success: 3 short blinks
Error: No feedback
2 x
Long
3s < Press < 5s,
Enter High Security Mode
(Encrypt and authenticate)
Success: 2 short blinks
Error: No feedback
< 1s Release,
3s < Press < 5s
Very
Long
> 8s Press
Factory Reset
Success: 5 short blinks
Error: No feedback
Table 4
–
STM 550 user interface actions
