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Fall Colors

Submitted by John on Tue, 09/17/2019 - 19:15

A brilliant orange and red leaf sitting on a tarmac surface

One thing I have been trying to do this autumn is stop and appreciate every leaf that catches my eye. I mean, I'm not taking photos of every one. Instead, just stop and be thankful for this little transient miracle that fell to earth.

I have picked up a couple of leaves and brought them into my office. And on one hand I know this is true but on the other hand, it's a little shocking how fast the leaves dry up and turn dull and brown and lifeless.

<strong>As for the synth,</strong> I've been super busy and not had much time but I have nailed down the analog filter for the VCO, now I am working on laying it out in SMT. I just had a real heck of a time orienting myself around SMT layout, and I still do. First off, I'm still getting used to only working on one layer of the PCB (yes I know about vias, but I find it hard to place them. I'm just iterating through this as, place related components together, rotate, try to route them, move them around some more.... etc. For something like this board, that has an analog ground and a digital ground, as well as some "high interference" PWM traces, I have some additional layout considerations I have to work through and it's not always easy.

Additionally, I think something just doesn't feel right with the KiCad defaults. The grid is off? Mixing 0603 and 0805 passives leads to some weird alignment issues, and I just don't get a nice orderly grid snappy in place feeling. I'm constantly fighting the router tool, it wants to jag off in weird ways I'm not expecting. I think a more experience will help, but I also think I could be changing some settings to get a better experience, I just don't know what those settings are.

New Polaroid Smartphone Printer Sounds Familiar

Submitted by John on Wed, 09/11/2019 - 18:27

Polaroid has this cool new smartphone printer that is basically a projector in a box that projects your photo from your smartphone on to traditional Polaroid instant film.

As soon as I saw it, I thought, wait, didn't I use an iPhone to make a picture once? After a bit of digging, I found my Flickr album of when I used an iPhone and an old camera as an enlarger back when we lived at our old apartment.

I would insert an image here, but I disabled downloading of images on my own Flickr and can't find it on my computer, so go to Flickr to see what I did. Basically, put the camera lens down, place film negative on the back of the camera, place custom light box (with appropriate contrast filter!) atop of the camera and film, etc. It was the original iPhone. And I only used it as a light source. The exposure time on the paper was over 10 minutes, due to reciprocity failure.

Anyway, thinking of that then reminded me of making contact prints with a monitor and photo paper, another wholly unpractical method of making photos.

World's Largest Guitar Pedalboard

Submitted by John on Tue, 09/10/2019 - 21:42

Guitarist Rob Scallon partnered with Sweetwater to set the world record for largest guitar pedalboard with 319 guitar pedals!

Super interesting to watch the team work through how much power the pedal board will use, what they think the whole thing will sound like, CAN THEY GET A CLEAN TONE? (h/t Miscellaneous Heathen)

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Made progress with my analog filter

Submitted by John on Mon, 09/09/2019 - 22:41

Tonight I finally got my first prototype filter mocked up for the 8 bit VCO. Okay, technically that's not true, I've made four separate output filters so far. But they've all had problems one way or another.

The first one, a passive filter, was just too rough. Second one was alright but I lost my paper with the component values on it. Easier to just design it all over again.

Third was a too aggressive 3 db ripple Chebyshev Sallen Key filter that ultimately had some strange aggressiveness in the high end when you mixed several VCOs together. I later learned that a Sallen Key filter can stop filtering in the stop band and boomerang back up and start passing more high end, and I suspect this was a contributing factor (could have been the ripple though).

Fourth one (the one I've been living with for the past 6 months) was another passive filter, but even worse than the first. (That's alright because I largely used it to prototype the LFO stuff I was working on.)

The problem I had with the first three designs is I just designed them on paper, implemented them on a PCB, and then lived with whatever happened next. So this time, I resolved to actually prototype something.

Now I have another 6 designs ready for testing. Tonight I finished up the prototype of my first design and... it sounds pretty good! So much better than the garbage I was living with before. It's a 3 stage multiple feedback filter, and I'm trying to decide if I keep prototyping or not.

One design I'm fairly excited about is a five stage filter, but to be honest, eventually I have to put this design into an SMT PCB. And, unfortunately, with the ongoing MLCC shortage, it's going to be a massive pain in the neck to get a decent prototype of an analog filter with 0603 capacitors. I'm going to have to redesign parts of this filter every time I order new caps, because they discontinue these packages so quickly, and they're always coming out with tweaks to the dielectric. So the thought of adding another two capacitors to this filter.... I can feel the annoyance level rising.

(I know that the above paragraph makes me sound like I know what I'm talking about but I've never actually built one of these filters in SMT in real life (yet!). But I have taken a few of my on paper prototypes and attempted to source some parts and the MLCCs are enough to drive a person completely bug nutty.)

All that to say I'm fairly happy with how the filter turned out tonight. My wife came into the room and she thought I was playing an Atari game!

Next steps are to tweak the filter values a bit, and look around for my design notes for the 8-bit VCO to see what was left in terms of software tweaks that it needed.

Boring Sitemaps

Submitted by John on Sun, 09/08/2019 - 18:46

A boy laying on the bed, looking at the cameraI feel bad when I spend a lot of time on this site that makes things better for me to administer the site, or SEO or whatever, but ultimately isn't making new posts. 

But that's what happened today!

Ah, I will make a sitemap. Research what I need to do to make that happen on Drupal. Pick the right module. Try to install the module using Composer, since I just got the site set up with Composer. 

Fails with an out of memory error. Whaaaaat? I thought I had a swap partition. I do have a swap partition!?

Turns out Composer needs a lot of RAM. Lots and tons and gobs. Okay how do I add more swap space to Linux again?

Finally, got the module installed, oh I have to adjust the permissions. Oh, more permissions and then by the time I get done making the sitemap, I'm like... eh? I guess it worked?

I guess it was fun going through all my old content and seeing what was there. 

 

Introducing very hot peppers to a very young child

Submitted by John on Sat, 09/07/2019 - 08:34

I introduced my daughter to Thai chili peppers last night. She's one and a half.

Let me explain.

Couple of days ago I made the Hawaiian Chili Pepper Water. Yesterday I used the remaining Thai and cayenne chili peppers from the garden to start a basic fermented pepper mash. I seeded the peppers and chopped them up, and this is where our story begins.

Although maybe this story should begin two weeks ago, with the sriracha. I have some amazing Vermont Maple Sriracha sauce that I got as a gift from my sister. One of the boys has taken a liking to tasting a tiny amount of it at a time (the rest of the family won't touch it). I have the sriracha out and I am giving it to the child. In comes baby sister.

"want some."
"No honey it's very spicy. It's hot OW!"
"hot ow!"
"Yes. Hot ow!"
"want some! some! hot ow! SOME!"

Eventually I gave in and gave her a teeny amount. She wound up loving it, going from a drop to pea sized to nearly a quarter teaspoon at a time with no problem. Never cried. I had to cut her off, because I was worried about any potential digestive effects if she kept it up.

Back to the present day. Now she knows what the word "spicy" means. She sees the pretty red pepper mash. It's the same color as the sriracha.

"picy. picy. want some picy!"
"Honey. This is very very hot ow spicy."
"picy. PICY!! want some!"

Eventually I gave in and got a piece of pepper about the size of a grain of sand and put that on her tongue.

[a pause]

Massive amounts of crying and tears. It was way hotter than she was anticipating. We are all out of milk because mommy is at the store buying milk. So I gave her cold water in a kids cup. 

She drinks down most of the water. Takes a couple deep breaths with red eyes, and looks up, looks me right in the eye.

"picy. want picy!"

She has another little piece of picy. I have a piece of picy. Four to five rounds of picy and three cups of water later, I ask her if she wants more. She thinks about it a moment and replies

"all done picy."

And that's the story of how my 1 and a half year old daughter and I ate some very hot chili peppers together.

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How to get the email of the currently logged in Salesforce user

Submitted by John on Fri, 09/06/2019 - 16:16

Earlier today I spent quite a bit of time trying to figure out how to get the email of the currently logged in Salesforce user. Specifically, using the SalesforceSDK in iOS, using Objective-C.

You'd think this would be easy. Just look at the documentation! Alas! Salesforce has not decided to invest much into the consistency and comprehensiveness of their documentation.

Okay. Google! Surely Google will have the answer!

Alas again! There are a zillion Salesforce frameworks out there! React, Swift, Objective-C, Android/Java, something called "Apex", whatever that is. All of these platforms do the same things, but in a slightly different way. So for a generic query, like "how do I get the email of the currently logged in user in Salesforce?" you'll have to wait

So add "Objective-C" to the query!

The final Alas! is that Salesforce has changed how to do this half a dozen times over the past 3-5 years. So you'll find solutions on how to do it with SFAccountManager, how to do it with SFAuthenticationManager, etc. This was a huge rabbit hole.

Eventually I found a method using SFUserAccountManager... although it too was deprecated! At least there were some Xcode hints on what the correct answer might look like however.

Finally, here's what works in Objective-C using MobileSDK 7.2:

[[SFUserAccountManager sharedInstance] userAccountForUserIdentity:[[SFUserAccountManager sharedInstance] currentUserIdentity]].idData.email

The email is in the idData object. There are a number of other good properties in there, like lastName, firstName, langauge, locale, all of your user info is going to be there.

Hope this helps!

Hawaiian Chili Pepper Water

Submitted by John on Thu, 09/05/2019 - 22:46

A jar of hot Thai chilis in water, next to another chili sitting on the counterInspired by It's Alive with Brad Leone I picked up a copy of Firey Ferments from the library. The book is all about making fermented hot sauces of all kinds (and other spicy ferments, like horseradish and mustard).

I tried looking for a the recipe so I could just link it but alas there are a zillion variations of this, most of which are not fermented. This is pretty much the version from the book:


Hawaiian Chili Pepper Water

  • 4-10 small hot peppers (I used 10 peppers, which were all varieties of Thai hot peppers, although some might have been cayenne)
  • 1 clove garlic
  • 2 slices ginger
  • 1 pint mason jar
  • 2 cups unchlorinated water, plus 1 tbsp salt (combine to make a brine)
  • 1 tablespoon of rice vinegar 

Peel garlic and ginger, remove stem end of peppers. Crush all ingredients with the back of a knife, and place in mason jar. Fill jar with brine, leaving 1 to 1 and a 1/2 inches of headspace. Screw jar lid tightly (no need to burp the ferment). Ferment for 1-2 weeks, until cloudy and it has a pickle like acidity. Add the rice vinegar. Keeps in the refrigerator for up to one year.


I just put it up tonight so I have no idea how it's going to turn out. It's quite a strong brine, but even after 5 minutes of it sitting there I could taste the freshness of the peppers in the water. I'm feeling pretty good about this one!

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