Electronic – Inductors with no value on schematic

Looks good at a quick look through. Nothing obviously bad.

BSS138 are especially wimpy MOSFETS. Ok for playing but do not do justice to the rest of the circuit. Not up to quad copter use, but, you know that.

DTR is intended to reset the processor I assume.

To pass the Olin schematic test you'd want (amongst other things)

• To move text strings off lines (eg PS3 PS4 by MOSFETs and rotate them to horizontal where sensibly possible. PWM3 label is overwritten by MOSFET name etc. VCC label in eg FTDI box turn 90 degrees.

• Have connectors from FETs vertically above FETs rather than bent at 90 degrees. Vbatt could be above or to one side.

• And similar

Aim is to not 'twist brain' to follow obvious flow.

Some people will read diagrams with small points as above and find them less than comfortable but bearable. Others will essentially refuse to look at them. The latter reaction is somewhat extreme but reflects an underlying semi-reality - a really tidy diagram with attention to layout, text and component orientation, consistent labelling and more SUGGESTS an underlying technical competence, and a messy diagram tends to suggest the onbious. Neither of these impressions may be correct, but they are often a useful starting guide. Also, arguably, a tidy diagram reflects respect for those who you expect to use it (and the validity and relevance this has been argued at length :-) ) and is more likely to allow you to spot technical errors.

NB: DO NOT ever take my diagrams as examples of how to do things well. I am a "classic messy" who attempts to force the world's mold on my output with varying success. Judgements based on normal standards may mislead one wrt the value of a classic messy's offerings - and may not :-). Equally a chronic super-tidy (who can in their own way be just as bad as a messy) may produce superb copy but not always match it with underlying competence. FWIW.

Some languages do not have the µ letter on the default keyboard and use mk as abbreviation for mikro. 1µF and 10µF are typical sizes for "big" blocking caps.

Using just n for nanofarad and pF for picofarad provides a stronger optical difference between these units. Most caps in a digital circuit are expected to be in n range (small blocking caps), you want the shortest form here with just one letter.