Connectivity (“Airwires”) Issues
- The DRC review for “Airwires” reports many connection errors (for example, errors such as “J3:1, U1:1”, “J3:2, R4:2”, “R3:2, R1:2”, etc.). This indicates that several pins that should be tied together are left “floating” or mis‐named.
- Many of these errors imply that the net names assigned to one side of a connection (for example, on a connector or within a resistor network) do not match the net expected on the receiving device.
- Suggestion: Systematically review each reported airwire error. Verify that each component’s pin (for example, the pins on J3 and the corresponding pin on IC1) is assigned the correct, identical net label. Correct any mismatches in naming or wiring so that every intended signal appears continuously on the schematic.
Power Distribution and Net Consistency
- Multiple power portals (such as those for PP5V0, PP3V3, and PP12V0) appear in the design. In several cases the review indicates that the supply pins (for example on [U1] and [U2]) are not consistently tied to the same named net.
- Suggestion: Verify that each rail (5V, 3.3V, 12V, etc.) is routed by a dedicated portal and that every active component’s power pin is connected to the same net. Inconsistent naming or accidental omission could lead to unintentional splits in the power distribution.
Signal Integrity and Pull-Up/Pull-Down Requirements
- For open-drain interfaces (such as I2C lines), proper pull-up resistors are a must. Although the schematic does include several “Net Portal” components for signals (for example, I2C_SDA and I2C_SCL), the reported airwire errors indicate that some of these signal nets are not fully connected.
- Suggestion: Confirm that every open-drain signal has the proper pull-up resistor placed on the same net and that those nets are not left with dangling connections. Additionally, double-check that any required current-limiting resistors (for example, on any LED or transistor base inputs) are in place.
Pin Assignments and Logical Consistency
- The review errors hint that some pins on major ICs (for instance, on the microcontroller IC1) might not be connecting as expected. In several cases, signals from [IC1] (like its clock, data, or control pins) are involved in airwire errors.
- Suggestion: Revisit the device datasheets and ensure that the schematic symbols use the correct pin numbering and that each pin is connected to the intended function. If the symbol was custom created or modified, verify that its pin mapping exactly matches the PCB footprint assignments and the manufacturer’s datasheet.
General Net Labeling and “No Connect” Flags
- There are “No Connect” objects included. Make sure that these are designated as such, and that they are not inadvertently tied to nets where they could cause shorts.
- Suggestion: Confirm that all “No Connect” pins or objects are either left unconnected in the schematic or are clearly marked in the design rules so that they do not affect net connectivity.