Tank sensors/Raspberry Pi fun...

[LaurV]

No reason to laugh, any thing from which you (general you) learn something is ok with me. Ok, I laugh a bit, because for a very long time I didn't see/use ICs in DIP packages, and because the filtering capacitors seem to conflict with the ICs (probably, the real capacitors will not be so fat like the footprint, I hope you know what you are doing, but anyhow, that is funny).

[chalsall]

Originally Posted by LaurV

Ok, I laugh a bit, because for a very long time I didn't see/use ICs in DIP packages, and because the filtering capacitors seem to conflict with the ICs (probably, the real capacitors will not be so fat like the footprint, I hope you know what you are doing, but anyhow, that is funny).

LOL... I *knew* you were going to call me out on that!

Not everyone has the ability to deal with SMT in-house! And, yeah, the bypass caps are tiny little 0.1 uF ceramics. I couldn't quickly find the right footprint, so just selected something with the correct pin spacing.

[nomead]

Originally Posted by chalsall

Not everyone has the ability to deal with SMT in-house! And, yeah, the bypass caps are tiny little 0.1 uF ceramics. I couldn't quickly find the right footprint, so just selected something with the correct pin spacing.

I've always wondered why people make this excuse "ability to deal with SMT"... I've found it actually much easier. No bending and clipping leads. If I make my own boards (rarely these days, Chinese suppliers make a bunch for like $10...) there's no drilling needed, unless I need through-hole connectors or jumper wires etc. I'll just choose passives in 1206 or 0805 size, not smaller. Add solder to one pad on the PCB. Pick up the component with tweezers, melt the solder again, and stick the resistor/capacitor in place. Then it stays put and it's really easy to solder the other end. The same with ICs, I just tend to choose the largest case size available, like SOIC (1.27 mm pitch) for logic chips. Tack one corner down with solder, then solder the diagonally opposite corner, then do the rest. I don't even have any particularly narrow tip on my soldering iron, I think it's a 2.4mm chisel-shaped one on a 20-year-old temperature-controlled Weller WECP-20.

Of course the smaller it gets, the harder it becomes. But even 0.65 or 0.5 mm pitch components can be done with that wide tip. Just use copious amounts of extra flux, gel or liquid, doesn't matter. With the soldering iron, wipe across all the leads on one edge, adding solder as you go. The flux prevents solder bridges, but if any do occur, they can usually be removed with good solder wick or just by applying more flux and reheating the solder joints. Much easier than trying to solder each pin separately.

Finally, some parts are difficult (QFN) if not impossible (BGA/CSP) to solder by hand with a soldering iron, so those are the ones to avoid if you can, but it usually isn't a problem when you get to design the PCB by yourself.

Lead-free soldering is a bit harder, so having enough flux is even more important there. Also the temperature of the soldering iron becomes more critical. The range where it works is narrower. Hot enough to melt the solder reasonably fast, but not too hot so that the flux is not burned off before the solder joint is formed.

[bsquared]

A friend of mine has done something like this, so I know it is very doable: toaster oven reflow.

https://www.allaboutcircuits.com/tec...r-oven-reflow/

A cool project in its own right, and possibly very helpful for all future DIY home electronic projects.