April Update

It’s been far too long since I’ve posted here, and the more time it was since that last post, the harder it became to post here.

So I’m just going to start again.

Mostly what happened is that I got stuck on some very frustrating bugs with my new hardware design and it took far too long for me to ask for help, so I lost all motivation to work on this project and found other shinier things to play with.

I’m now past that hurdle, and I think I have a way to keep motivation and progress going in the right direction.  I’m going to have a weekly or so meeting where I can ask for help and people can ask me basic questions about my designs, helping me to fix problems as they come up, and readdress all my basic assumptions.

This is basically what most advisers do for their students, keep them on task by asking questions and act as a sounding board for problems.  Maybe that’s something that could/should be used more widely in at-home science arenas?

Another inspiration for me is that ZeFrank came back.  My current favorites are this classic motivation, and this brand new motivation.


General updates since my last post:


Following a series of discussions with my analog adviser (hi Steve) and my physics adviser (hi Lee), I’ve started working on version 0.4 of the electronics (now with actual theoretical chance of working!). I received the (painfully small) surface mount parts from DigiKey and Newark, and managed to solder them to SMD-DIP adapters for breadboarding.

Things I learned:

  • Arduino ints only go to 2^15, that is a problem when dealing with 16-bit DACs.
  • My new DAC’s “write” command only means here’s some information, not do something with the information I’m giving you.


Bart from BuildLog sent some makerslide, a 400-step stepper motor, and other amazing things as part of his Makership project so I can build a solid linear actuator for the rough approach.

Funding and Support:

Wow, thanks so much to all the amazing people who decided to help this project with funding, parts donations, and their generous time:


Chicago Awesome Foundation

Individuals: Nikos G., pdp7, T. Joseph N., David C., Bruce G.


Bart from BuildLog.net

Time and advice:

Steve F., Ian S., Lee

image credit


8 Responses to “April Update”

  1. Allen says:

    I’m glad to see you are back. I found your website a few months ago and submitted the RSS feed to my email account hoping that I would see an update again someday. Thanks for coming back to the project I look forward to following more updates in the future! Good luck and hope things go well!

  2. Avner says:

    That new ZeFrank video you posted is really excellent. Thanks for posting it, and glad to see you’re working on this again.

  3. Wayne says:

    for the 16bit ADC results you should use uint16_t, this gives you exactly the right range (2^16 positive values rather than 2^15 positive and negative)

    • Sacha says:

      @Wayne: woah, thanks! That is exactly what I needed, that saves me a good chunk of memory over using LONG! I’ll implement that today.

  4. Joseph says:

    Glad to know you are back in the saddle. Keep riding that horse all the way to the finish line!

    Just a suggestion, as I know you have done much work up to this point and have ideas, might it be useful in order to obtain feedback:

    - put your ideas future updates into sketches, drawings, pictures, video, write-ups, code and /or descriptions and post them
    - post the old stuff
    - what the hell…put up a kickstarter if you need funds…just sayin’ then market like hell. ;-)

    Anyway, my couple of cents….

    Thank you for the AWESOME work you have done thusfar including putting up with TSA when you were traveling. It would be very cool if you were able to go to SF Maker Faire!

  5. brenhammer says:

    Been following this in the shadows for a while. Just want to post some moral support for this awesome project.

  6. Timmothy Furmom says:

    CHEMHACKER(I believe in you){
    return STM;

    Also, DW has some words of encouragement for you around 3:38…

  7. Nick says:

    Should have gone with the ARM Cortex! 32 bit and lots of peripherals, so no problems working with the large samples. Not that it’s a huge burden for the programmer if you use the stdint.h types, but depending on how demanding the firmware becomes over time, doing 16 bit math on an 8 bit CPU could be a drain.