remember user-input boolean values after power off?

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monkeybiscuits

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Hi, I'm making a teensy midi controller with a few small buttons. Sometimes I need button to be momentary and sometimes I need a latch. It's easy enough to make the button behaviors switchable by using boolean values and a 'shift' button. But is there anyway to save those boolean values after the teensy has been powered down? I'm sure the SD shield could store whatever I need but that seems like overkill if all I need are a few boolean values.
 
You can use the EEPROM area on the chip to store a few bytes. Teensy 2.0's have 1,024 bytes. Teensy 2.0++'s have 4,096 bytes. Teensy 3.0/3.1's have 2,048 bytes. See the library page for more details: http://www.pjrc.com/teensy/td_libs_EEPROM.html.

Be sure to use a recent version of the teensyduino software. Some of the older revisions cleared out EEPROM values in the 3.0/3.1 when you load a new program. That has been fixed for a long time, but just in case you have an older release, you might want to consider moving up. With the latest releases, you can load a program to set up the defaults, and then load a different program to use them. Note, EEPROM memory has limited write cycles (100,000), so you might want to update the EEPROM only when the switch value changes.
 
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