How do I tell KiCad where the power is coming from on a Eeschema

Question

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

Andy aka · Accepted Answer · 2021-09-15T10:26:55.240

3

ErrType(3): Pin connected to other pins, but not driven by any pin

Connect a power flag symbol to power lines to inform KiCad: -

Pin not connected (use a “no connection” flag to suppress this error)

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.

edited Sep 15 '21 at 10:26

answered Sep 15 '21 at 10:02

Andy aka

434,556
28
351
777

I will follow your instruction this evening (after work). Thank you for the information :) – guttih Sep 15 '21 at 10:31
@GuðjónHólmSigurðsson don't forget to come back tomorrow! – Andy aka Sep 15 '21 at 10:38
thanks for your input. I stole a little time from work to apply your fixes as best I could. I added the results to the original post (edited) starting from "Update Fix 1". There are still some errors I'm not sure how to fix, could you help a little with that? – guttih Sep 15 '21 at 13:20
Thanks @andyaka (testing how to refer to users in comments) – guttih Sep 15 '21 at 13:34
@guttih yes, your test worked!. The remaining errors appear to be power pin conflicts but you still have some pins that can be fixed with the blue X as indicated in my answer. For your power pin conflicts, I normally set all relevant pins to be passive so that the conflict disappears. [Please read this](https://electronics.stackexchange.com/tour) to understand why people give help for free. – Andy aka Sep 15 '21 at 13:44
Note that the blue cross attaches at the free end of the pin and not how you attached on U_3.3V1. Also edit your symbols to rotate pins 4 and 2 so that they point outwards from the chip. – Andy aka Sep 15 '21 at 13:49
Thank you for all your help @andyaka, I'm error free, wohooo :) – guttih Sep 15 '21 at 14:51