Hack a little bit

By building the String Synth project, I’ve noticed that the envelope module had attack and decay way too fast.
So, I’ve rebuild one envelope bit and changed a resistor ( blue circle )and a capacitor ( yellow circle ).
I’ve changed the resistor into 120 Ohms instead of 100 Ohms
The capacitor changed from 1uF to 4.7uF.
These parts can be obtained via online electronic parts stores.

Now, the attack at max. has 4 seconds ( original was 1 sec. ), the delay becomes now 12 sec. ( original was 3 sec. ).

You can hear these slow attacks and decays throughout the song I’ve composed in the Synth String project. They can also be heard in the slow moving noise waves.

You need a steady hand and magnifying glasses to solder them though :smiley:





You did nice work for such close quarters! SMD repair just scares me. I’m good with removing parts, but just get solder all over when I try to put something back on.

Good job!

Hi @chris101,
I think most important, is to get the smd parts with the right dimensions. Here’s what I do :smile:

  • careful removing of the smd parts with desolder braid.
  • clean the contact surface with nail polish remover ( works best ), using ear cleaning buds.
  • add a tiny bit of solder ( yes, no lead free :smile: ) to one contact.
  • usage of a soldering iron with fine tip. I use one with controllable temperature
  • use twizzers to solder one contact of the smd chip.
  • then solder the other contact
  • clean the solder area with polish remover, using cotton ear cleaner buds.
  • double check if there are no shorts ( no, not the pants :smile: )

Soon, I will change the capacitor on the timeout bit. I really don’t need delays of 5 minutes.
It’s so hard to tune the tiny potentiometer on this module for timeouts of a few seconds.
I’ve calculated that a capacitor of 10uF suits my timing needs.


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The timeout bit has also been modded :smile:
I’ve changed the 220uF capacitor into 10uF.
This gives a timing range from 0 to 16 sec.
Now, if I want longer timings, I still have another timeout bit, unmodified.
Soon, I will publish a project which uses the 2 modded bits.

Has anyone ideas or suggestions for hacking other bits ?
Share your ideas here :sunglasses:

Modified bit


Great shares, @Frankje :blush: I’m curious about how you use the timeout. I usually want more time, not less. I made my own timeout that has dip switches. My intention was to have a single resistor attached to each dip switch and have discrete timing available. I made a big oops and tied the resistors together, which resulted in averaging any resistors selected by the dip switch. The result was a pleasant weirdness. :wink:

Hello @JackANDJude ,
Great idea to use dipswitches for timing selections !
I’m not too sure but I think by adding a latch bit after the timeout bit, will double the time.
I mostly use the timeout bit together with some pulse bit at the input. This way, you can use it as a long high, fast low pulse.
Great for controlling sudden short actions.
I will publish today a project that uses the modded timeout and envelope bit. Also, the optocoupler will play a significant role.
The project will be called sea tides, it produces full automatically the whoooshh and rrrooouuhh of a rolling sea.
It uses lots of littlebits and no arduino.

Voilà !
The project, which uses these 2 modificated bits, is published on the inventions page : http://littlebits.cc/projects/seashore-soundwaves
The modded timeout bit retriggers at certain intervals the modded envelope bit.
This creates a LFO ( Low Frequency Oscillator ). The shape of this LFO can be controlled by the Attack & Decay knobs.
This LFO modulates the filter cutoff of the first noise generator.
This LFO also controls the RGB bit ( inside the OptoCoupler ), so the volume of the noise is also modulated;
This LFO is transformed to a reversed ( 180° ) pulse, by using the Threshold and Inverter bit.
This pulse is fed to a 2nd ( not modded ) Envelope bit, which controls the cutoff of a 2nd Filter bit.
The outputs of these 2 filters are mixed and inserted in a delay.
Woohaa, I almost scared myself by rereading this post :open_mouth:


The i21 Microphone bit …
Almost everybody complains thar the i21 microphone bit is not sensitive enough.
If we look at the schematic, we will see that the mic preamp has lots of resistors.
If we calculate the total amount of amplification, R7 / ( R2 + R5 + R6 ), the value is 1.43.
This is not enough to pick up sounds and voice.
If we change R4 and R5 into 1 Ohm and change R7 into 470k, the amplification will be 42.3.
Approximately 30 times higher.
This is perfect for the microphone bit to be sensitive.
Now, there’s one drawback. The line input ( mini jack ) will increase also in sensitivity. But since we mostly use a headphone output from laptop, smartphone, …, it’s impedance will be low, so the preamp will work without distortion if we will lower the volume on our playback device.
OK, I’ve changed the 3 resistors ( yellow circles ) and tested with different circuits.

  • The bargraph will blink the last LED when speaking at a normal distance of the microphone.
  • Music from my smartphone sounds good when listening through the synth speaker.
    Here’s a snippet of the PCB and schematic with the parts to be replaced in yellow circles.

The PCB shows the new SMD resistors already soldered


Hi there
Is there any way I can find the exact map for this Littlebits Timeout circuit so that I can assemble it myself?


nearly all bit diagrams can be found here on github:

and here:

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