I just ordered an HDK! What thru-hole components pair well with it?

As the title says, I just ordered an HDK! :laughing:

I’m pretty excited, but I was just wondering what thru-hole components are recommended for the littleBits format. I am mostly interested in the the variable resistance of the pots used as well as the most common values for resistors and capacitors.

I have plenty of breadboards and components to keep myself busy, but I want to be sure I am using the most similar parts as possible to littleBits due to the bitLab. :grinning:

1 Like

Interesting question @blindbento. Look through the littleBits Github eagle files. These will show you all of the components used in real life littleBits. For prototyping I use 10K pots, because they are easy to obtain, and the range works well. Fixed resistors: 75-1M. Caps: 6nf - 1f. Occasionally I use inductors - a single turn around a small ferrite torus for input power, and 10-100uH for LC filtering.

Op-amps are important in littleBits circuits. You will want a 5 volt single supply, then the decision is to use an expensive through hole rail-to-rail amplifier, or not. I use LM324 or NTE928 if I do not need rail-to-rail characteristics, or OPA4342 quad amps if I do.

I use various other chips as needed. For microprocessors, I prototype with Arduino boards, but go forward using ATTiny chips. I use internal oscillators if I can, cheap ceramic resonators or flat-can crystals.

Hi @blindbento,
You can also find nearly all wiring diagrams in PDF format in the shop. Just scroll down at each bit for technical info.
I copied them on my PC for easy access…

1 Like

@chris101, @alexpikkert Thanks for the advice! :grinning: I will be sure to get the circuit diagrams from github. Which Eagle file viewer do you recommend?

I think that I will stick to using TL07X opamps for the time being, but if there is any reason to not use them, I would appreciate knowing. :innocent:

1 Like

Hi @blindbento,

You won’t need an Eagle viewer - the pdf file (also available here http://littlebits.cc/shop/bits - scroll to the bottom of any bit’s page) has the schematic, and you can see it in a browser or pdf viewer.

I’m not familiar with the TL07X opamp, but it’s datasheet indicates that it needs a dual supply and is not rail to rail. The LVM321 (smt) amps that littleBits uses, and the OPA4342 (dip14) that I use, are single supply and rail to rail. This simplifies the circuit design considerably. However if the ones you have do the job, then use em!

Yeah, the TL07X series is always useful for synth circuits.If you open up any modern synth module you will see lots of TL07X and LM13700 chips. However, that is a very good point about needing less components to get the power sorted. After all, the range for the bits is 0 to 5 volts.

For my own use, more components isn’t an issue, but for a final product, less components is preferred. I will probably have to order some OPA4342 or similar chips in the future.

I really do appreciate the advice as the littleBits format is still new to me. I only just figured out standard gate to littleBits trigger signal conversion. :bitstar: