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What additions are good to add to a prototype PCB that makes your life easier?

I have come across a few nice additions such as:

  • Adding useful information on the silkscreen to designate functional areas/pins/traces. Revision number.
  • LEDs for power and micro activity.
  • Test points at important places in the circuit.
  • Connecting a spare communication channel to a header.

Are there others that are helpful?

kpnz
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I'd add large silkscreen rectangle, pref.on both sides - to add various Sharpie marks when necessary. Lots of small bare copper islands to store SMT parts you have just removed but may need later - just solder one pin to the closest island :-). Extra non-tented ground vias next to likely probe points - to solder a ground wire that will then be wrapped around a probe. Extra 0.1" jumpers where you may want to clip your current probe.

Oleg Mazurov
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Two pads with holes about 1mm diameter, about 1/2 inch apart, both grounded.

Solder a thick wire rail to these, like a hitching post outside a Western saloon, and you'll have a secure place for the crocodile clips on your scope ground leads.


If you're going on to a small production run, (50 or so) consider identifying every net that doesn't naturally connect to an external connector, and connecting it to a pin on a ribbon cable header (or a few small 10-way headers). This can be a lower budget option than adding test points for a "bed of nails" fixture.

Then you can build a test fixture that attaches to your board with just a few ribbon cables, and allows you to test for things like shorts to power or ground without the expense of a full "bed of nails" fixture.

See Majenko's answer to this Q&A for a really neat trick with staggered pins, to make good connection without fitting sockets...

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This seems overly broad, really; but anyway - extra bypass capacitor pads (you may never populate them, but if you want them, it's nice to have them.) This is actually not uncommon to find in production boards, complete with silkscreened part numbers for the missing capacitors.

Most everything else depends a lot on the actual circuit. Pads set up to make a solder bridge or places set up to cut a trace easily might make sense, but which things to do that for will vary, and it's always something of a gamble since you should not need to do either if you get it right, but you may not guess right how you'll get it wrong.

It can be a good idea to provide unequivocal revision tracking and things like two-pin device polarity clues (square .vs. rounded pad) right in the copper - depends on the available real estate.

Ecnerwal
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  • Yes I was hesitant to ask it so broadly, but I could only find guides to general PCB design rather than luxury additions to help development. – kpnz Mar 26 '16 at 03:15
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    Another nice design item is a few processor GPIO pins pulled high with pads to install 0 ohm resistors to ground to be able to electronically specify a HW revision. This is to allow a single software load act correctly even with significant PCB revisions in the future. – DoxyLover Mar 26 '16 at 03:50
  • @DoxyLover That's a cool idea. Why do you need the 0 ohms? Just in case you want to get rid of it? – kpnz Mar 26 '16 at 06:59
  • @KylePennington11 Just in case you "green wire" revise the board, you can change the stuffing of the revision jumpers. If you don't need that, just have traces that you change from rev-to-rev. – DoxyLover Mar 26 '16 at 11:32
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    @DoxyLover Instead of using multiple digital pins, what I've done is to use one analog input, and make a resistor divider which is populated so you have 12 voltages from 0.25 to 3.0 volts (assuming a 3.3v supply). 0.25v steps are far enough apart to be easily discernible. If the device is battery operated, and there is concern about the continuous current drain, even a few µA while the device is asleep, then drive the top of the resistor divider from an output pin whose function could be shared with something else, for example driving an LED or the TX output from a UART which is normally high. – tcrosley Mar 28 '16 at 00:19
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Every IC pin to goto a via (outside device footprint). This will facilitate you cutting and modding if you find an error.

Surface traces as much as possible. Again to facilitate cutting and modding.

Make available liberal points of 0V and Vcc around the board. Sometimes the placement of cap's is enough but sods law dictates that the ONE signal you want doesn't have a convenient GND nearby, or when you need to add a cockroach mod there isn't a nearby power...

If you have space OPAMP/COMPARATOR's terminate them correctly so that

  1. they do not cause rail issues when they are not in-use
  2. You can then easily configure them to any of the std blocks

schematic

simulate this circuit – Schematic created using CircuitLab