0
\$\begingroup\$

I want to realize a wireless keypad using ESP-32 and a matrix 4x3 keypad, connected via Bluetooth Low Energy to a master unit. I want to use deep sleep mode of ESP-32 when the keypad is not used but I need to wake up the ESP when a key is pressed, while not loosing the input. As far I understood, the matrix keypad needs the CPU running in order to understand which key has been pressed. Is there maybe some other way or component that I can use for this? Thanks for your suggestions.

\$\endgroup\$
2
\$\begingroup\$

There is a possibility to use lo power mcu that is build in the esp32 for reading the input while main cores are in deep sleep, but as far as i have been using it only with touch keypad.

It's not a full answer, but should help You.

https://www.espressif.com/sites/default/files/documentation/esp32_datasheet_en.pdf

Page 5, RTC block with ULP co-processor

also: https://github.com/espressif/esp-idf/tree/master/examples/system/ulp

https://blog.adafruit.com/2018/02/20/deep-sleep-tutorial-for-esp32-using-the-rtc-ulp-co-processor-and-two-lines-of-code/

This can handle the keypad feauture with wakeup for main core.

Hope it helped.

\$\endgroup\$
  • \$\begingroup\$ Welcome to electronics.stackexchange.com. Keep up the good work. \$\endgroup\$ – Maple Jun 17 '18 at 8:35
  • \$\begingroup\$ No problem, without help of others on this and many other forums or websites i would not have the knowledge I have. So if there is a way to give back to others what i have received when needed, i'm always willing to help. That's what community stands for, right? :) \$\endgroup\$ – Mirosław Drdzeń Jun 20 '18 at 23:54

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.