One thing to be aware of: spark fun's schematics are generally flaming crap, along with most arduino stuff.
> Sometimes, to make schematics more legible, we'll give a net a name and label it, rather than routing a wire all over the schematic.
Net labels are the anti-readable-schematic. They're basically the electronics equivalent of GOTO. This is total bullshit.
People use net-labels when they don't want to bother spending time to make their schematic flow properly, or they're doing something dumb like drawing their schematic symbols with the pin-positions from the physical IC.
Good schematics should make the overall operation of the system easy to discern. You should have a consistent signal-flow (generally left-to-right, though the opposite also works). More complex systems should also use a hierarchical design with the interfaces between logical sections being clearly defined.
I think you are being quite harsh, net labels are fine for embedded/digital stuff, which generally consists of quite separate functional blocks with few, easily reasoned signals between them (e.g. power + I2C). A lot of Sparkfun's products fall into this category.
If you look at say laptop or SoC development board schematics, they are full of net names, and they certainly aren't using physical pin positions. In fact quite the opposite, one physical device is often split into multiple schematic symbols (e.g. supply rails are one symbol). For the overall system, they use a block diagram or hierarchical schematic. Here is the BeagleBone schematic, which I think makes good use of net labels, e.g. the BAT connection on page 2: https://beagleboard.org/static/beaglebone/BEAGLEBONE_SCHEM_A...
I will agree with you on net names for analog systems, such as audio amplifiers or complex power supplies. There, net names can quite often be misused, as you need to keep more connections in your head when trying to understand a circuit, and it is much harder to remember all the net names than see a direct connection.
As I said, net labels are like GOTO. There are very specific situations where GOTO (or net labels) are useful.
They're also used in lots and LOTS of other situations where they're actively harmful.
Contexts like spark-fun designs, where the layout is almost always only one page is a situation where they're actively harmful.
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I've done large, complex system designs without using net-labels at all. It takes a lot of thought about how to structure your component symbols, and was considerably helped by my EDA tool (Altium) having a facility to bundle multiple logically associated but non-bus wires into a single logical connection ("signal harnesses" - they're great), as well as very robust hierarchical design facilities.
It's absolutely possible to do, and you wind up with a much nicer schematic in the end, but it does take longer.
On the other hand, a site like spark-fun in particular sells educational components. The fact that they don't have decent schematics is really extremely disappointing.
Net labels are situation dependent. They can incerase or decrease readability depending on the signal flow. For example I would not like to see a complex board with a central microprocessor where each signal is wired up directly! OTOH having to chase a signal through 3 different sheets is a huge pain (this was especially bad when I had to read PDF exports from a (very expensive) tool where the net labels were not searchable nor linked in any form!).
For example I would not like to see a complex board with a central microprocessor where each signal is wired up directly!
this was especially bad when I had to read PDF exports from a (very expensive) tool where the net labels were not searchable nor linked in any form!
...like the majority of laptop schematics out there seem to be structured, where the CPU, GPU, and chipset are sitting on their own page with nothing but net labels attached to them? At least the ones I've come across have a list of the other page numbers where the net can be found, next to the label.
Very true. About the only time I find net labels acceptable is buses (otherwise the multiple lines clutter the schematic) and multi-sheet connections. Can't find it now, but back in around 2005 I found a basic 555 circuit for beginners with every connection to the chip besides power & ground being a net. IIRC, the pins weren't even laid out to match the chip. Every time I run across a spark fun schematic I have flashbacks to that. Which is a real shame, since the company's goal is to educate newbies. And it isn't impossible, Adafruit generally does a good job of this.
> Sometimes, to make schematics more legible, we'll give a net a name and label it, rather than routing a wire all over the schematic.
Net labels are the anti-readable-schematic. They're basically the electronics equivalent of GOTO. This is total bullshit.
People use net-labels when they don't want to bother spending time to make their schematic flow properly, or they're doing something dumb like drawing their schematic symbols with the pin-positions from the physical IC.
Good schematics should make the overall operation of the system easy to discern. You should have a consistent signal-flow (generally left-to-right, though the opposite also works). More complex systems should also use a hierarchical design with the interfaces between logical sections being clearly defined.