Barnaby Walters

Arranging atoms and pressurising air in a variety of manners, such as:

Pronouns: they/he

  1. Has anybody tried using concentric pots (like this one) on a module to have the control and attenuverter for a parameter in the same place? i.e. the upper knob is the value/offset, and the lower knob would control CV input attenuvertion.

    Generally I prefer having a real knob for control and a trimmer for attenuvertion, but stacking them could save space for “micro” modules.

  2. Sven: neat! Which market did you find this at?

    @HeNeArXn Rathaus Schöneberg, last Sunday. I’d not been before but it seems like a good market for old electronic junk! There were a bunch of cassette recorders and a really cool old film projector too.

  3. Found at a market in Berlin: what I think is an old DIY oscilloscope, complete with handwritten panel lettering!

    I’m guessing this could have been a build by someone living under the GDR who couldn’t get hold of a scope.

  4. Noticed that, having learned to use the beating effect to tell when two pitches are slightly out of tune, I now can trick myself into thinking that in-tune sounds are out of tune by applying light sine-shaped tremolo to them. Wonder if this works for people who haven’t learned to tune using beats?

  5. Julian Oliver: To be an ex-pat in Germany is to accept you will be routinely 'Germansplained', a unique kind of explanation whereby you're not only told why what you've done is wrong &/or not good, but told it >=3 times & that if you do it again you're an idiot. Often followed by chirpy goodbye

    @julian0liver I believe the verb is “klugscheißen” https://en.pons.com/translate/german-english/klugschei%C3%9Fen I have extensive experience with this as well!

  6. Put my laser engraver to good use for the first time, engraving text and graphics for a Walnut front panel for my Shruthi XT synth. I’m really happy with the results!

    I ended up using Eazydraw to design the panel as usual, then after some searching discovered LaserWeb4, an amazing open source CAM tool designed for laser usage but also with routing capabilities.

    It took some time and experimentation to figure out how best to engrave the various text and graphics. In the end I found that Inside cuts along the text, on-path cuts on most of the graphics and some particularly thin text, and inside cuts+fills with very carefully set margins on the inverted filled sections produced good results.

    I’m definitely going to be looking into LaserWeb4 in more detail. I want to investigate it’s conventional routing CAM cabapilities, and potentially switch to this over using Easel, as LW4 is open source, allows for much more detailed control of the machine, and runs offline.

  7. Ben Werdmuller: I built my first website in 1995; started distributing my hypertext magazine in 1994; got on the internet the same year. Distributed my first shareware game via BBS in 1993. 2017 was the first year I didn’t put something new I’d made online in 24 years. Will fix this in 2018.

    @benwerd 2017 was pretty rough though tbh

  8. ✅ improved gurdy MIDI system
    ✅ improved 3 channel gurdy preamplifier
    ✅ DIY hybrid digital+analogue synthesizer

    After a year of work on the hardware and software, finally all the pieces are in place to start composing!

  9. Tom Morris  🏳️‍🌈: Duolingo is amazing. Learning how to deny being a horse ("yo no soy un caballo") before learning boring stuff like checking into hotels or getting a taxi at the airport is precisely the sort of surrealist approach to language education I appreciate.

    @tommorris after starting learning German just with Duolingo, my approach with new languages (currently French) is to do the Duo and Memrise courses in parallel. I like the approach. Duo has more complex sentences and better grammar help even if the vocab is a bit random, whereas Memrise has better audio (on the official courses at least) and the vocab is much more goal-oriented.

  10. I added a cheap 1W laser diode to my X-Carve CNC machine for a total cost of €100 (€40 of which were laser safety goggles)

    There are a multitude of these laser diode+controller packs available from China on eBay, from 1W to 12W. They typically don’t come with any documentation so it took some experimentation to figure out how to connect it.

    My driver module required a 12V DC power supply, and then had a connector for ground and a 5V PWM signal, the duty cycle of which controls the laser power output. I tested this with a PWM signal from my Analog Discovery 2, and plugged it into gshield pin D11 (grbl spindle PWM output) after confirming it worked.

    The latest build of grbl (1.1f) from Inventables supports laser mode, which makes some changes to the way M3-5 commands are handled, as well as making some changes to the acceleration to try to ensure linear laser power application.

    All I had to do to set up laser mode was to activate it with $32=1 and set a max speed of 100 with $30=100 so that the laser power could conveniently be expressed as a percentage. If you use a speed-controllable spindle then you’ll either have to change this setting every time you change to laser mode, or express laser power in terms of your max spindle speed.

    One confusing thing I found about M3 (always-on) laser mode was that the laser wasn’t always on. I had to send an empty G1 command to turn the laser on for focusing, and then it would turn off again every time a G0 was sent. I suppose this is a good safety feature, but does seem to contradict the laser mode documentation.

    Generally I set up the laser (positioning, focusing) in M3 and then switch to M4 for cutting.

    I created a reference board showing cuts at different power levels (y axis) and feedrates (x axis):

    This shows that whilst cutting through anything other than paper probably isn’t possible with this little 1W diode, I’ll be able to get some really nice results engraving into wood, and hopefully other materials.

    I was really hoping that I’d be able to run the laser engraver without dust extraction (i.e. much more quietly than milling!) but quickly noticed that the laser would often hit puffs of smoke generated from cutting, leaving gaps in the cut. Dust/fume extraction and high diode power levels are definitely a must for good results!

  11. FREE: ATmega1284p TQFN to DIP adapter boards available for Shruthi/Ambika/open source work!

    TL, dr; I had a batch of adapter boards for the ATmega1284P (a pin-compatible upgrade to the ATmega644 used in the Mutable Instruments Shruthi and Ambika open source synthesizers) built which enable an SMD version of the chip to be inserted into the DIP socket on the MI boards. I now have loads of them and am giving these boards away for free to people who want to work on open source Shruthi/Ambika firmware! I’m also happy to assemble them for a few euros.

    For context:

    Why the ATmega1284P?

    This chip is a drop-in, pin-compatible upgrade to the ATmega644 used in the original Ambika and Shruthi designs, which provides twice the flash available in the 644p. This is particularly important for Ambika firmware development because the stock firmware, and YAM, uses up almost all the space.

    Why not just use a DIP ATmega1284p, if they’re pin-compatible?

    As previously discussed on the Mutable Instruments forums, the DIP ATmega1284p chips have a hardware fault related to the UART used for MIDI functionality which can cause the chip to crash. The SMD version of the chip apparently doesn’t have this fault, and therefore using the SMD chip via an adapter board should fix the problem and act as a drop-in replacement without having to totally redesign the synth.

    I designed this board last month and now have 44 of them. I’m sending some to the developer of the excellent YAM firmware, and will experiment with a few myself, but I have no need for so many.

    So, if anyone’s interested in doing firmware development work on Ambika or Shruthi, or using these for any other open-source purposes email me barnaby@waterpigs.co.uk your address, paypal me the shipping costs if it’s going to be more than a couple of euros, and I’ll send you some boards!

    I’m also happy to assemble the boards with headers and ATmega chip for €8 + P&P per board, if anyone wants.

    Disclaimer: the boards are untested, and I personally have not tested them with the shruthi hardware or firmware! I may not have time to do so but will post my experiences here when I get round to it. Point is, these boards are strictly experimental with no guarantee they actually work!

    Boards in stock as of 2017-11-18: 32

  12. Aaron Parecki: ugh that's the worst. That happened to me with that smart thermos thing. They're sold at the apple store now to rub it in.

    Yeah, it’s bad enough when campaigns fail completely, but taking pre-orders, successfully developing and selling the product, but not shipping to backers, or otherwise acknowledging them at all? Very dishonest behaviour.

  13. Unexpected effect: German bagpipe organisations are advising their customers to buy Scottish bagpipes now, because the pound is so weak compared to the euro:

    “Profit from the low pound exchange rate”

  14. Anyone know of good open source time tracking software? Preferably web server + app. I’m using Toggl at the moment, but would love to self host and am amazed that the only projects I can find are very old and rather clunky looking.