The problem
I am a beginner/novice using KiCad and in creating PCB's, so I do not know much about these things. After following tutorials from YouTube I managed to create or copy symbols to my library and connect footprints to them. But now, when I start connecting them in the schema I get a lot of errors. I think most of them are because I am not telling KiCad where the power is comming from, even though I've added a Barrel Jack which has a power output on the VCC pin.
I am working on creating a PCB for my WaterMixer project.
KiCad project files
The KiCad project files (including the project symbol and footprint libraries) are located in the hardware directory on the branch I'm currently working on.
The Eeschema
Here is an image of my Eeschema which can be opened from the hardware folder if anybody is interested.
The errors
Here are the errors generated by electrical rules checker (the debugger) if someone needs more information to answer the question.
ERC report (15.9.2021 09:44:30, Encoding UTF8 )
***** Sheet /
ErrType(3): Pin connected to other pins, but not driven by any pin
@(220,98 mm, 142,24 mm): Pin 10 (Power input) of component U4 is not driven (Net 5).
ErrType(5): Conflict problem between pins. Severity: error
@(121,92 mm, 125,73 mm): Pin 2 (Power output) of component U_5V1 is connected to
@(119,38 mm, 125,73 mm): pin 2 (Power output) of component U_5V1 (net 9).
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(133,35 mm, 179,07 mm): Pin 3 (Passive) of component J_12V1 is unconnected.
ErrType(3): Pin connected to other pins, but not driven by any pin
@(172,72 mm, 74,93 mm): Pin 1 (Power input) of component U2 is not driven (Net 17).
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(199,39 mm, 116,84 mm): Pin 7 (Bidirectional) of component U3 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(199,39 mm, 93,98 mm): Pin 6 (Bidirectional) of component U3 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(204,47 mm, 116,84 mm): Pin 5 (Bidirectional) of component U3 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(204,47 mm, 93,98 mm): Pin 4 (Bidirectional) of component U3 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(172,72 mm, 57,15 mm): Pin 8 (Bidirectional) of component U2 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(172,72 mm, 59,69 mm): Pin 7 (Bidirectional) of component U2 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(172,72 mm, 62,23 mm): Pin 6 (Input) of component U2 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(172,72 mm, 67,31 mm): Pin 4 (Input) of component U2 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(172,72 mm, 34,29 mm): Pin 17 (Bidirectional) of component U2 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(172,72 mm, 36,83 mm): Pin 16 (Bidirectional) of component U2 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(172,72 mm, 44,45 mm): Pin 13 (Bidirectional) of component U2 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(172,72 mm, 49,53 mm): Pin 11 (Bidirectional) of component U2 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(172,72 mm, 52,07 mm): Pin 10 (Bidirectional) of component U2 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(172,72 mm, 31,75 mm): Pin 18 (Bidirectional) of component U2 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(236,22 mm, 134,62 mm): Pin 8 (Output) of component U4 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(205,74 mm, 137,16 mm): Pin 5 (Output) of component U4 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(205,74 mm, 134,62 mm): Pin 4 (Input) of component U4 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(102,87 mm, 49,53 mm): Pin 28 (Bidirectional) of component U2 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(102,87 mm, 69,85 mm): Pin 36 (Bidirectional) of component U2 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(102,87 mm, 67,31 mm): Pin 35 (Bidirectional) of component U2 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(102,87 mm, 64,77 mm): Pin 34 (Bidirectional) of component U2 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(172,72 mm, 69,85 mm): Pin 3 (Input) of component U2 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(102,87 mm, 46,99 mm): Pin 27 (Bidirectional) of component U2 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(102,87 mm, 41,91 mm): Pin 25 (Bidirectional) of component U2 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(102,87 mm, 34,29 mm): Pin 22 (Bidirectional) of component U2 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(102,87 mm, 31,75 mm): Pin 21 (Bidirectional) of component U2 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(102,87 mm, 29,21 mm): Pin 20 (Bidirectional) of component U2 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(172,72 mm, 72,39 mm): Pin 2 (Input) of component U2 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(76,20 mm, 74,93 mm): Pin 9 (Output) of component U1 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(35,56 mm, 85,09 mm): Pin 18 (Input) of component U1 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(121,92 mm, 146,05 mm): Pin 1 (Power input) of component U_5V1 is unconnected.
ErrType(3): Pin connected to other pins, but not driven by any pin
@(55,88 mm, 90,17 mm): Pin 2 (Power input) of component U1 is not driven (Net 64).
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(110,49 mm, 146,05 mm): Pin 3 (Passive) of component U_5V1 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(113,03 mm, 146,05 mm): Pin 3 (Passive) of component U_5V1 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(119,38 mm, 146,05 mm): Pin 1 (Power input) of component U_5V1 is unconnected.
ErrType(5): Conflict problem between pins. Severity: error
@(67,31 mm, 118,11 mm): Pin 2 (Power output) of component U_3.3V1 is connected to
@(64,77 mm, 118,11 mm): pin 2 (Power output) of component U_3.3V1 (net 68).
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(55,88 mm, 138,43 mm): Pin 3 (Passive) of component U_3.3V1 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(58,42 mm, 138,43 mm): Pin 3 (Passive) of component U_3.3V1 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(64,77 mm, 138,43 mm): Pin 1 (Power input) of component U_3.3V1 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(67,31 mm, 138,43 mm): Pin 1 (Power input) of component U_3.3V1 is unconnected.
** ERC messages: 44 Errors 2 Warnings 42
Update Fix 1
After suggestion from "Andy aka" I've Added a PWR_FLAG and marked pins not used. This Fixed a lot of errors. But now I'm not sure how to fix the rest. I'm adding a new Image to show what I did and also adding the image of the two symbols I suspect having the wrong pin types.
Images of the new (Fix1) Schema and the symbols
the Schema after Fix1
The Schema after fixing it with "Andy aka" suggestions.
Symbols
I suspect that the pin types could be wrong on these symbols.
Symbol Barrel_Jack
The 12V power plug.
Symbol SD_BUCK3A
The power step down voltage module to produce 3.3V and 5V power.
The errors after Fix 1
ERC report (15.9.2021 12:32:00, Encoding UTF8 )
***** Sheet /
ErrType(3): Pin connected to other pins, but not driven by any pin
@(214,63 mm, 102,87 mm): Pin 1 (Power input) of component U3 is not driven (Net 5).
ErrType(5): Conflict problem between pins. Severity: error
@(121,92 mm, 125,73 mm): Pin 2 (Power output) of component U_5V1 is connected to
@(119,38 mm, 125,73 mm): pin 2 (Power output) of component U_5V1 (net 9).
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(151,13 mm, 185,42 mm): Pin 1 (Power output) of component #FLG02 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(151,13 mm, 166,37 mm): Pin 1 (Power output) of component #FLG01 is unconnected.
ErrType(12): Different net assigned to a shared pin in another unit of the same component
@(64,77 mm, 138,43 mm): Pin 1 on U_3.3V1 is connected to both VCC and Net-(U_3.3V1-Pad1)
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(133,35 mm, 176,53 mm): Pin 2 (Passive) of component J_12V1 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(121,92 mm, 146,05 mm): Pin 1 (Power input) of component U_5V1 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(236,22 mm, 134,62 mm): Pin 8 (Output) of component U4 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(205,74 mm, 137,16 mm): Pin 5 (Output) of component U4 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(205,74 mm, 134,62 mm): Pin 4 (Input) of component U4 is unconnected.
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(119,38 mm, 146,05 mm): Pin 1 (Power input) of component U_5V1 is unconnected.
ErrType(12): Different net assigned to a shared pin in another unit of the same component
@(58,42 mm, 138,43 mm): Pin 3 on U_3.3V1 is connected to both Net-(U_3.3V1-Pad3) and GND
ErrType(3): Pin connected to other pins, but not driven by any pin
@(102,87 mm, 59,69 mm): Pin 32 (Power input) of component U2 is not driven (Net 61).
ErrType(5): Conflict problem between pins. Severity: error
@(64,77 mm, 118,11 mm): Pin 2 (Power output) of component U_3.3V1 is connected to
@(67,31 mm, 118,11 mm): pin 2 (Power output) of component U_3.3V1 (net 66).
ErrType(12): Different net assigned to a shared pin in another unit of the same component
@(113,03 mm, 146,05 mm): Pin 3 on U_5V1 is connected to both GND and Net-(U_5V1-Pad3)
ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)
@(76,20 mm, 74,93 mm): Pin 9 (Output) of component U1 is unconnected.
** ERC messages: 16 Errors 5 Warnings 11
Best Answer
Connect a power flag symbol to power lines to inform KiCad: -
And use a no-connect symbol on pins that are unused: -
That should sort out most of them.
I would also recommend that you use symbols for Vcc and GND rather than traipse them across the schematic. You might need a few more de-coupling capacitors too on Vcc/Vdd pins to ground.