Feelin' Not Hot Hot

This here is my stove. It came with the house. I probably wouldn't have bought a Samsung if it had been my choice, but as of yet I have no particular reason to get rid of it.

But that doesn't mean it's working perfectly. Far from it, in fact: it has two issues with the oven.

One of those issues is that it hasn't been preheating quite as well as it should be, and it tends to sound a little hesitant when I first turn it on. Like the igniter will come on, then the gas will start flowing, but sometimes the gas will stop and start again a few times, sort of hesitating, and the burner will flame out and reignite.

But thankfully it's pretty easy to just have a little look inside, only these two screws at the back here need to be removed to get the bottom panel of the oven off.

We've still got this diffuser to get through, and it's a bit cracked down the middle but still serviceable.

And finally we can see the burner assembly.

I was concerned that it might be rusted or clogged, but it seems to be fine.

Which is nice because a new burner is around $100 or so. And that kind of confirms my suspicion that it's probably the hot surface igniter that's on its way out.

It certainly looks a little crusty in there. There's a safety circuit in the oven control board which measures the current through the igniter and if it's too high or too low then the gas valve shuts off to avoid making your oven explode. Which is, you know, I guess a nice feature to have.

Anyway, these cost about $30 to get a generic one from the House of Bezos.

And yoinking out the old one starts with pulling the oven out, so that we can access the rear panel.

This connector here is what supplies the igniter with power, and it needs to be unplugged so that the burner assembly can be removed.

Like so.

Taking a peek through the grille, it's definitely looking a bit crusty.

So let's see, did I get the right replacement?

Well it sure looks the same.

Just, you know, newer.

But the important question is: does it work?

Sure looks like fire to me.

Anyway, I said that there were two problems with the oven, and the second problem is the oven door switch.

It's been flaky and intermittent for a while, so I ordered a new door switch for like $3 like maybe 2 years ago and just never got around to installing it, for reasons you're about to see. But ignoring this problem didn't seem to make it go away, so I guess it's time to actually do something about it.

And that starts with pulling the grills and burners off the cooktop.

And then pulling off the cooktop, which is quite easy to do when you remember to push in these little clips at the front, and don't forget and just yank it off by force.

Not that I would do anything like that.

Next up these screws down the side come out.

Including this obnoxious one in the back.

And then once those, and the ones down the back, are out, we can... remove more screws and panels.

And then we're finally at the switch.

After pulling off the connectors on the back you just need to press in the little metal tab on each side and it slides right out the front.

And then it's just out with the old and in with the new.

Except there's one slight problem.

This switch is the wrong polarity.

It's supposed to be normally-closed, but instead it's normally-open.

Now sometimes you can open up these switches and reconfigure them, but that ain't happening with this one.

So instead let's just crack open the old one and clean the contacts on it instead.

As they are looking a little bit crusty.

And a tad bit tired.

But after a little scrub with a brass brush...

They... kinda look the same?

It seems to be working, though, so we'll go with it.

Hmm, yup.

Yeah, that's more like it.

As for the new switch, the return window has long since expired so it's off to become microplastics floating in the ocean.

And in the meantime I'll be enjoying a working oven.

At least until the next time it breaks.

Vitality

For a while now I've been baking bread with AP flour. This has worked out relatively well, but the recipe I'm using really toes the line of hydration and enrichment, which means that it demands a lot of the flour, and the natural variation thereof can sometimes come up a bit short in the structure department.

Back in the day I used to bake bread with bread flour, which is absolute easy-mode. I keep my pantry stocked with AP now, though, because I bake a lot of other things like the crusts for my pot pies or my chocco chip cookies, which very much do not benefit from an excess of gluten in the flour. Like, to be honest, they'd probably be fine since the fat (and sugar, in the case of the cookies) would likely tenderize things sufficiently for the gluten to never stand a chance, but all purpose is supposed to be all purpose.

The last batch of bread turned out particularly cakey and crumbly, so I decided it was time to make a change. Not by buying bread flour (because honestly, owning two different types of flour is getting a little too deep into the baking hobby than I really want to allow myself to get), but rather by buying some wheat gluten.

Sorry, my bad, it's ✨vital✨ wheat gluten. You know, as opposed to the usual optional, inessential wheat gluten.

Just look at how vital this is.

Anyway, I'm using 510g of AP flour total so I'm trying 15g of gluten to see what that does. By my calculation it should land things at almost 15% gluten. Depending how things go I might back it down to 10g, which would yield around 14% total.

There's already 30g of flour in the yudane, so 480 goes into the bowl.

And then whisking it together dry is rather important so that you don't accidentally make a wad of seitan in the middle of your loaf of bread.

My usual gauge for how well the bread will come together is seeing if it sticks to the spatula or pulls away cleanly, and we're looking good on that front.

And it kneaded up very well, with a good amount of springiness.

The first rise looks promising, with no slumping around the edges.

And the second rise shows promising structure too.

Out of the oven I got a good amount of spring that didn't collapse during baking.

And no tearing across the top, just a little bit around the edges which is quite normal.

As per usual this is just the first bake. One loaf goes in the freezer and the other loaf stays on the counter until Sunday evening when it'll get the second bake to brown it up and reset the starches. So far, I'm pretty confident in these loaves.

Like Engineering, But Backwards

Reverse engineering is just the time-reversed antiparticle of regular engineering, and when the two collide it usually results in a massive release of energy. Today that energy is being released through a soldering iron, adding some header pins to this DE-9 pass-thru adapter I got.

Like this.

Why do I need them? Well, I'm glad you asked.

This is my Roland S-760, connected to my Roland RC-100 by way of this convenient pass-thru DE-9 adapter, complete with a very convenient set of header pins. Header pins that I can attach scope probes to, in order to see signals like this.

The purple trace on top is the clock line, and the yellow trace is the data line. The S-760 sends out a long high-pulse on the clock line to initiate the data transfer, and then the RC-100 responds by toggling out the most significant bit of the 7-bit word. Each bit thereafter is put on the data line shortly before the next low-to-high or high-to-low clock pulse, to give us a double data rate signal at around 60kHz.

The initial clock pulse is about 45 microseconds long.

And the data is put on the bus about 5 microseconds before the clock transition.

The RC-100 asserts an ATTN signal by pulling it low in order to notify the S-760 that it wants to send a packet. It holds it low for the entire transfer, including when sending a 2-byte sequence for the dial motion: a zero followed by a signed 7-bit value for the relative rotation since the last transmission (positive is clockwise).

As you might imagine, there's no consistent timing between the ATTN signal and the start of transfer. The S-760 just gets around to it when it gets around to it.

And, hmm, these header pins are getting a little bit crowded.

Ok, using a ribbon cable makes things a lot easier to manage.

The S-760 will send LED updates using a sequence of 4 bytes. I've only observed the first two bytes being used, however, so I don't know what the function of the second two is.

Now you might think that this first block of 14 bits maps to the 14 LEDs on the device in an order that makes logical sense based on the logical pin ordering of the IC they're connected to. Or perhaps one based on the component designators.

But neither of those appears to be correct. It seems like the MCU in this device does some logical reordering to map the bits to the LEDs in an order that's roughly in line with the physical layout of the device. Here's a dump of the start-up chaser sequence it does after a reset:

And this corresponds to Play->Edit->Disk->MIDI->Func->Utility->F1->F2->F3 twice, then lighting up Edit-Disk-MIDI-Func-Utility all at once.

Poking around, it looks like Menu is 0x4000 and Command is 0x0100. I haven't managed to get Sub Menu, Execute or Rec to light up from interacting with the S-760, so I'll have to see if I can just inject some data to map out the remaining bits.

But how am I capturing this, and how am I planning to inject this data?

With a friendly little Arduino Nano, of course.

Anyway, how about the mapping in the other direction? Well the high bit is for key-down: 1 for down, 0 for up. From there, it goes like this:

0-9: 0x00-0x09, conveniently

Enter: 0x0A

Inc/Yes: 0x0B

Dec/No: 0x0C

Right, Left, Up, Down: 0x0D to 0x10

Del: 0x11

Ins: 0x12

Play, Edit, Disk, MIDI, Func, Utility: 0x13 to 0x18

Menu, Sub Menu, Command, Execute: 0x19 to 0x1C

F1, F2, F3: 0x1D, 0x1E, 0x1F

Start/Stop, Rec: 0x20, 0x21 (these are hard-wired to the pedal inputs, so the same values are used there)

Now one sneaky thing I should mention here is that while the RC-100 transmits to the S-760 at around 60kHz, the same is not true in the other direction: setting the LEDs is a much more leisurely data rate.

The bits are clocked at 33kHz, or 30 microseconds, and the initial pulse lasts a solid 85 microseconds.

And that tripped me up for a while. (Ignore the yellow trace in these pictures, I didn't have that probe connected)

Anyway, I only have a bit more work to do in order to map out the final three LEDs, and then I'll be ready for the next phase of the project. More to come then!