PCB Schematic Design for ESP32 IoT Sensor
Thought for 45 sec
Yes — the 24 errors are mostly PCB routing status, not 24 broken schematic connections.
What they are
Table
| Type | Count | Meaning |
|---|---|---|
| Airwires | 23 | Unrouted PCB connections between pads |
| ERC Missing Power | 1 | U1 pin VP is being treated as an unpowered power-input pin |
I checked the project reviews directly; that’s the correct place to inspect ERC/DRC issues in Flux
Important detail
- The 23 airwires are expected right now because the PCB has footprints placed, but the board is not routed yet.
- The only actual schematic/ERC issue is:
- U1 : VP flagged as “Power input not connected”
On the ESP32 DevKit symbol, VP is likely the ADC/GPIO pin label, but its pin type in the library is probably marked as power input, so ERC is complaining even though it is not meant to be tied to a supply in your design.
What I recommend
- Ignore the 23 airwires for now if you haven’t done PCB routing yet.
- Fix the single ERC on U1 by either:
- marking VP as intentionally unused with a No Connect, or
- using a different ESP32 DevKit part whose pin typing is cleaner.
If you want, I can fix that one ERC warning on U1 for you next.
Fix the U1 VP ERC warning.
Thought for 38 sec
I marked U1 VP as No Connect.
- The change was applied successfully.
- The ERC review is still showing the same warning, which usually means the review result has not refreshed yet.
If it still remains after a moment, the root issue is likely the ESP32 DevKit part definition treating VP as a power-input pin in a way No Connect does not suppress. In that case, the proper fix is to replace U1 with a cleaner ESP32 DevKit part, which is a multi-step change.
Replace U1 part
Check other ERC issues
Inspect U1 pins
Thought
nets {
net SD_MOSI = U1:D23, U5:CMD/SI;
net GND = U2:GND_TAB, U2:GROUND, GND:GND, U1 GND_1 - U3 8:GND, C3:P2, C2:P2, U2 GND_TAB - U2 ON/OFF:GND, U2:ON/OFF, J1:Terminal, C4:P2, U1:GND, U1:GND_1, U4:GND, U3:10, C1:P2, U5:GND, R1:P2, U3:8, LED1:K;
net VCC_3V3 = U4:VDD, LED1:A, C3:P1, U3:14, U1:3V3, C2:P1, U3:9, R1:P1, U5:3V, R2:P1, C1:P1;
net SD_CS = U1:D5, U5:D3/CS;
net ONE_WIRE = U1:D4, U4:DQ, R2:P2;
net SD_CLK = U5:CLK, U1:D18;
net VCC_5V = C4:P1, U2:FEEDBACK, U2:OUTPUT, U1:VIN;
net SCL = U3:11, U1:D22;
net SD_MISO = U5:DO/SO, U1:D19;
net SDA = U3:12, U1:D21;
}
