Power cables

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I’ve made another batch of cables. These ones are power cables. For connecting my bench power supplies to breadboards.

I made two sets of banana plugs to DC male with inline switches:

And two sets of DC female to jumper pin:

And one set of DC female to DC male with inline switch:

Before I made these cables I figured out that it’s best to install the SPST switch into the positive wire.

My soldering started out pretty bad:

But I got better:

I tested both full sets:

Both green light:

Now I have a DC Power cable drawer:

New cables

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I made some new cables (the ones on the right). They’re banana plug to square socket. They complement the ones on the left, which are banana plug to pin jumper. The pin jumpers can plug into the square sockets.

I also installed the two black hooks to hang them on. The silver hook with the hot glue gun on it was already there.

For each type there are two pair of short ones and one pair of long ones.

SPI: The serial peripheral interface

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Watched this one from Ben Eater: SPI: The serial peripheral interface. I found it while watching this one: Hacking a weird TV censoring device, which was kind of hilarious, he reverses a profanity filter and finds its dictionary.

I noticed Ben Eater has a Keysight DSOX1204G Oscilloscope, a pretty nice looking bit of kit. Oh dear, he also seems to have a Keysight DSOX4024A Oscilloscope, which is an even nicer looking bit of kit.

When I have some time I’m gonna get some of these BME280 knockoffs and see if I can play along with the SPI video.

New shelf

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So I installed this shelf. It’s the black wiry thing:

But it was a bit of an ordeal. I managed to snap not one, but *two* screws while bolting it in.

The drill bit on the left was a casualty of trying to repair the mess. One screw shaft was irredeemably stuck in the wood, I couldn’t get it out. The other one I needed to drill around to get it out, it was stuck hard. Then I just plugged the hole I had created with craft sticks and hot glue, then tried again.

The spirit level says I did a fairly reasonable job of it:

Software optimization resources

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At last! A website that looks worse than mine: Software optimization resources.

The above resources were referenced from an article I read today: The World’s Smallest Hash Table. Also mentioned were Integer division by constants: optimal bounds and the Avalanche effect.

In cryptography, the avalanche effect is the desirable property of cryptographic algorithms, typically block ciphers[1] and cryptographic hash functions, wherein if an input is changed slightly (for example, flipping a single bit), the output changes significantly (e.g., half the output bits flip). In the case of high-quality block ciphers, such a small change in either the key or the plaintext should cause a drastic change in the ciphertext. The actual term was first used by Horst Feistel,[1] although the concept dates back to at least Shannon’s diffusion.