55c083f9 cc93 4de5 ba4a f87775b18a8e


Book Light & Reading Timer

by JackANDJude

Published on April 11, 2015

This circuit is like an "Itty Bitty Book Light" with a timer.  It displays how many minutes have already passed, and the long led stays on until the set reading time is finished.  Now there's no more reason for Jack to keep asking me if his 20 minute reading time is done.  :)   

The trick with this circuit is to combine the timeout (set to one minute) with the Number and threshold (set to value 21).




How To Make It

STEP 1 : Set timeout Bit to one minute

463806b4 81ea 489d 8a74 ce7409e78efa

Set timeout to one minute, using the purple screwdriver and this circuit:

power + button + pulse (around a second or a little less) + long led + timeout (on-off) + Number (up)

Press down and hold the button and start another timer at the same time. When the Number plus module increments one, the timeout has finished. Check your household timer and make micro-adjustments to the timeout with the purple screwdriver until you have approximated one minute. Visit the Tips & Tricks for the timeout: http://littlebits.cc/tips-tricks/fridays-tips-tricks-the-timeout-bit

STEP 2 : Set threshold to minutes + 1

3ca52f85 8601 4155 a083 b3c5b3cbc6f2

Set the threshold module to go high after the amount of minutes plus one has been reached on the Number module. You can use this circuit to set the threshold:

power + dimmer + Number (value) + threshold + led

Turn the dimmer until the Number reads (Number of minutes + 1). In our case, that is 21. Starting from the far right position, slowly turn the threshold counter clockwise until the led turns on. Your threshold is now set.

Visit the Tips & Tricks for the threshold: http://littlebits.cc/tips-tricks/tips-tricks-threshold

STEP 3 : Assemble final circuit

6019a4d7 4855 45a9 9405 d50e02467b7f

Assemble the final circuit on sticky shoes:

 p1 power + pulse + timeout + wire + Number (up) + threshold + inverter + long led

Leave room on the board for the book. Clip the back cover of a hardcover book to the board. You can reset this timing circuit by turning the power off then on.

STEP 4 : Additional feature

F02c67c5 7fef 4dc2 acf2 1e7b5e2804d4

If you have a toggle or slide switch, you could place that before the pulse and turn off the timer momentarily without losing the time already tracked.

Related Projects

Earth Day: My Personal Carbon Footprint

As Walt Kelly observed way back in 1971, solving a problem often involves the realization that oneself is the cause of the problem...


Whale made with styrofoam and cardboard!


This is a little bits windmill based of of little bits own little breezy, the windmill as well as the mill its self it also has a ...