Schematic Design Issue Review

flux

3:12

Analyzing circuit components.

Reviewing circuit connections.

Assessing pull-up resistor needs.

Checking interrupt and power connections.

Evaluating net connections and components.

Checking pin connections and net names.

Running design review.

Analyzing the schematic.

Reviewing the bill of materials.

Accessing knowledge base.

Planning tool calls for schematic review.

Here is a focused, schematic-level review of your current design. I’m only calling out what is directly observable in the schematic and BOM.
Electrical and logical issues
  • Power pin connectivity
    • U2 VCC is on VBAT; U1 VS and VDD_IO are on VBAT; all GND pins of U1 and U2 are tied to GND. No ERC “Missing Power” errors reported.
  • SPI wiring
    • MOSI/MISO/SCLK/#CS are point-to-point between U1 and U2 on nets Net 7/Net 6/Net 16/Net 15 respectively. No pin-type conflicts reported.
  • SWD wiring
    • U2 SWDIO and SWCLK go through series resistors R1 and R3 to J2 pins 2 and 4. GND at J2 pins 3/5/9 and VBAT at pin 1 are present.
  • Reset net
    • U2 P0.21/~RESET is connected to J2 pin 10 and to C1 to GND (Net 14). There is no external pull-up/down resistor visible on this net.
  • Button input
    • SW1 pin 1 -> U2 P0.17 (Net 10), SW1 pin 3 -> GND; C6 from the button node to GND. No external pull-up/down resistor is present on this input.
  • Unused/legacy net portals
    • Multiple Net Portal components (e.g., named for SPI, reset, crystal, button) are placed but not actually connected to the functional nets. The active nets carry generic names (Net 7/Net 6/Net 16/Net 15/Net 14/Net 10/etc.). This is confusing and risks accidental miswires later.
Component-level review
  • Decoupling and bulk caps
    • VBAT has multiple 0.1 uF decouplers C3/C4/C5 to GND and bulk caps C2/C9 = 47 uF each on VBAT to GND. Presence is good.
    • Crystal load network for Y1 is implemented: C7 and C8 to GND; U2 P0.00/XTAL1 to Y1:2 (Net 9), P0.01/XTAL2 to Y1:1 (Net 11).
  • LED current limiting
    • LED1 anode is fed via R2 to VBAT (Net 17/VBAT). Cathode returns to U2 P0.18 (Net 3). Current-limiting resistor is present. BOM shows R2 = 2.2 kΩ.
  • SWD series damping
    • R1 and R3 are 33 Ω each in series with SWDIO/SWCLK. Presence confirmed in BOM.
  • Battery input
    • J1 POS connects to VBAT; NEG to GND. No reverse-polarity or input transient protection components are present on VBAT.
Power and signal integrity
  • Power distribution
    • Single rail VBAT powers U2 and U1. Bypass caps and bulk caps are present on VBAT. No intermediate regulation stage is present.
  • Signal integrity
    • Series resistors are only on SWD lines. SPI lines (Net 6/7/16/15) have no series terminations in the schematic; nothing inherently wrong is visible here at schematic level.
Schematic best practices and net labeling
  • Generic net names on critical signals
    • SPI and other key nets use generic names: Net 7 (MOSI), Net 6 (MISO), Net 16 (SCLK), Net 15 (ACC_CS), Net 8 (ACC_INT1), Net 2 (ACC_INT2), Net 10 (BUTTON), Net 3 (LED), Net 14 (RESET). Rename these nets to their functional names so they are self-documenting and recognized clearly by ERC.
  • Unused legacy portals
    • Remove or connect the stray Net Portal components intended for SPI/RESET/XTAL/BUTTON so the net names match the intended signal names. Keeping unconnected portals increases the chance of mistakes.
  • Power net metadata
    • Add a voltage property to VBAT and mark it as a Power net type. Clear power net naming and properties improve ERC/DRC behavior and readability.
Actionable corrections and optimizations
  • Reset net
    • Observation: No external pull resistor is present on U2 P0.21/~RESET (only C1 to GND). Action: If the device requires an external pull, add a pull-up per the module’s datasheet. If the capacitor is not recommended, remove/adjust per guidance.
  • Button input
    • Observation: No external pull-up/down on U2 P0.17 (button net). Action: If you are not relying on the MCU’s internal pull, add the appropriate pull resistor.
  • Net labeling cleanup
    • Rename the following nets:
      • Net 7 -> MOSI
      • Net 6 -> MISO
      • Net 16 -> SCLK
      • Net 15 -> ACC_CS
      • Net 8 -> ACC_INT1
      • Net 2 -> ACC_INT2
      • Net 10 -> BUTTON
      • Net 3 -> LED
      • Net 14 -> RESET
    • Delete or properly connect the currently unconnected Net Portal components for these signals.
  • Power net properties
    • Set VBAT as a Power net and add its voltage value in net properties.
  • Battery input robustness (optional improvement)
    • If needed for your use case, consider adding reverse-polarity protection and/or input surge/ESD protection on VBAT ahead of the rail that feeds U2/U1.
What I verified via project data
  • ERC summary: No schematic-level ERC errors reported (Missing Power, Pin-to-Pin conflicts, Single pin nets, Undriven nets all clear).
  • Crystal network is correctly cross-connected with its two load capacitors to GND.
  • LED has a series resistor; SWD lines have series resistors; decoupling and bulk capacitors exist on VBAT.
  • Several disconnected Net Portals exist while the live nets remain generically named.
If you want, I can:
  • Rename the nets listed above and remove the stray Net Portal instances.
  • Add pull resistors on RESET and the BUTTON input if you confirm they’re needed.
70 days
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ACC_INT1
ACC_INT2
MISO
MOSI
ACC_CS
U2
  • Ground
    Ground
    A common return path for electric current. Commonly known as ground.
    jharwinbarrozo
    20.5M
  • Net Portal
    Net Portal
    Wirelessly connects nets on schematic. Used to organize schematics and separate functional blocks. To wirelessly connect net portals, give them same designator. #portal
    jharwinbarrozo
    43.0M
  • Power Net Portal
    Power Net Portal
    Wirelessly connects power nets on schematic. Identical to the net portal, but with a power symbol. Used to organize schematics and separate functional blocks. To wirelessly connect power net portals, give them the same designator. #portal #power
    jharwinbarrozo
    11.4M
  • Generic Resistor
    Generic Resistor
    A generic fixed resistor ideal for rapid circuit topology development. Its footprint automatically adapts based on the selected package case code—supporting 0402, 0603, 0805, 1203, and many other standard SMD packages, as well as axial horizontal and vertical configurations. Save precious design time by seamlessly add more information to this part (value, footprint, etc.) as it becomes available. Standard resistor values: 1.0 ohm, 10 ohm, 100 ohm, 1.0k ohm, 10k ohm, 100k ohm, 1.0M ohm 1.1 ohm, 11 ohm, 110 ohm, 1.1k ohm, 11k ohm, 110k ohm, 1.1M ohm 1.2 ohm, 12 ohm, 120 ohm, 1.2k ohm, 12k ohm, 120k ohm, 1.2M ohm 1.3 ohm, 13 ohm, 130 ohm, 1.3k ohm, 13k ohm, 130k ohm, 1.3M ohm 1.5 ohm, 15 ohm, 150 ohm, 1.5k ohm, 15k ohm, 150k ohm, 1.5M ohm 1.6 ohm, 16 ohm, 160 ohm, 1.6k ohm, 16k ohm, 160k ohm, 1.6M ohm 1.8 ohm, 18 ohm, 180 ohm, 1.8K ohm, 18k ohm, 180k ohm, 1.8M ohm 2.0 ohm, 20 ohm, 200 ohm, 2.0k ohm, 20k ohm, 200k ohm, 2.0M ohm 2.2 ohm, 22 ohm, 220 ohm, 2.2k ohm, 22k ohm, 220k ohm, 2.2M ohm 2.4 ohm, 24 ohm, 240 ohm, 2.4k ohm, 24k ohm, 240k ohm, 2.4M ohm 2.7 ohm, 27 ohm, 270 ohm, 2.7k ohm, 27k ohm, 270k ohm, 2.7M ohm 3.0 ohm, 30 ohm, 300 ohm, 3.0K ohm, 30K ohm, 300K ohm, 3.0M ohm 3.3 ohm, 33 ohm, 330 ohm, 3.3k ohm, 33k ohm, 330k ohm, 3.3M ohm 3.6 ohm, 36 ohm, 360 ohm, 3.6k ohm, 36k ohm, 360k ohm, 3.6M ohm 3.9 ohm, 39 ohm, 390 ohm, 3.9k ohm, 39k ohm, 390k ohm, 3.9M ohm 4.3 ohm, 43 ohm, 430 ohm, 4.3k ohm, 43K ohm, 430K ohm, 4.3M ohm 4.7 ohm, 47 ohm, 470 ohm, 4.7k ohm, 47k ohm, 470k ohm, 4.7M ohm 5.1 ohm, 51 ohm, 510 ohm, 5.1k ohm, 51k ohm, 510k ohm, 5.1M ohm 5.6 ohm, 56 ohm, 560 ohm, 5.6k ohm, 56k ohm, 560k ohm, 5.6M ohm 6.2 ohm, 62 ohm, 620 ohm, 6.2k ohm, 62K ohm, 620K ohm, 6.2M ohm 6.8 ohm, 68 ohm, 680 ohm, 6.8k ohm, 68k ohm, 680k ohm, 6.8M ohm 7.5 ohm, 75 ohm, 750 ohm, 7.5k ohm, 75k ohm, 750k ohm, 7.5M ohm 8.2 ohm, 82 ohm, 820 ohm, 8.2k ohm, 82k ohm, 820k ohm, 8.2M ohm 9.1 ohm, 91 ohm, 910 ohm, 9.1k ohm, 91k ohm, 910k ohm, 9.1M ohm #generics #CommonPartsLibrary
    jharwinbarrozo
    1.5M
  • Generic Capacitor
    Generic Capacitor
    A generic fixed capacitor ideal for rapid circuit topology development. You can choose between polarized and non-polarized types, its symbol and the footprint will automatically adapt based on your selection. Supported options include standard SMD sizes for ceramic capacitors (e.g., 0402, 0603, 0805), SMD sizes for aluminum electrolytic capacitors, and through-hole footprints for polarized capacitors. Save precious design time by seamlessly add more information to this part (value, footprint, etc.) as it becomes available. Standard capacitor values: 1.0pF, 10pF, 100pF, 1000pF, 0.01uF, 0.1uF, 1.0uF, 10uF, 100uF, 1000uF, 10000uF 1.1pF, 11pF, 110pF, 1100pF 1.2pF, 12pF, 120pF, 1200pF 1.3pF, 13pF, 130pF, 1300pF 1.5pF, 15pF, 150pF, 1500pF, 0.015uF, 0.15uF, 1.5uF, 15uF, 150uF, 1500uF 1.6pF, 16pF, 160pF, 1600pF 1.8pF, 18pF, 180pF, 1800pF 2.0pF, 20pF, 200pF, 2000pF 2.2pF, 22pF, 220pF, 2200pF, 0.022uF, 0.22uF, 2.2uF, 22uF, 220uF, 2200uF 2.4pF, 24pF, 240pF, 2400pF 2.7pF, 27pF, 270pF, 2700pF 3.0pF, 30pF, 300pF, 3000pF 3.3pF, 33pF, 330pF, 3300pF, 0.033uF, 0.33uF, 3.3uF, 33uF, 330uF, 3300uF 3.6pF, 36pF, 360pF, 3600pF 3.9pF, 39pF, 390pF, 3900pF 4.3pF, 43pF, 430pF, 4300pF 4.7pF, 47pF, 470pF, 4700pF, 0.047uF, 0.47uF, 4.7uF, 47uF, 470uF, 4700uF 5.1pF, 51pF, 510pF, 5100pF 5.6pF, 56pF, 560pF, 5600pF 6.2pF, 62pF, 620pF, 6200pF 6.8pF, 68pF, 680pF, 6800pF, 0.068uF, 0.68uF, 6.8uF, 68uF, 680uF, 6800uF 7.5pF, 75pF, 750pF, 7500pF 8.2pF, 82pF, 820pF, 8200pF 9.1pF, 91pF, 910pF, 9100pF #generics #CommonPartsLibrary
    jharwinbarrozo
    1.5M
  • Generic Inductor
    Generic Inductor
    A generic fixed inductor suitable for rapid circuit topology development. The footprint automatically adapts based on the selected package, supporting standard SMD sizes (e.g., 0402, 0603, 0805) as well as well-known inductor packages such as SDR1806, PA4320, SRN6028, and SRR1260. Standard inductor values: 1.0 nH, 10 nH, 100 nH, 1.0 µH, 10 µH, 100 µH, 1.0 mH 1.2 nH, 12 nH, 120 nH, 1.2 µH, 12 µH, 120 µH, 1.2 mH 1.5 nH, 15 nH, 150 nH, 1.5 µH, 15 µH, 150 µH, 1.5 mH 1.8 nH, 18 nH, 180 nH, 1.8 µH, 18 µH, 180 µH, 1.8 mH 2.2 nH, 22 nH, 220 nH, 2.2 µH, 22 µH, 220 µH, 2.2 mH 2.7 nH, 27 nH, 270 nH, 2.7 µH, 27 µH, 270 µH, 2.7 mH 3.3 nH, 33 nH, 330 nH, 3.3 µH, 33 µH, 330 µH, 3.3 mH 3.9 nH, 39 nH, 390 nH, 3.9 µH, 39 µH, 390 µH, 3.9 mH 4.7 nH, 47 nH, 470 nH, 4.7 µH, 47 µH, 470 µH, 4.7 mH 5.6 nH, 56 nH, 560 nH, 5.6 µH, 56 µH, 560 µH, 5.6 mH 6.8 nH, 68 nH, 680 nH, 6.8 µH, 68 µH, 680 µH, 6.8 mH 8.2 nH, 82 nH, 820 nH, 8.2 µH, 82 µH, 820 µH, 8.2 mH #generics #CommonPartsLibrary
    jharwinbarrozo
    15.9k
  • Terminal
    Terminal
    An electrical connector acting as reusable interface to a conductor and creating a point where external circuits can be connected.
    natarius
  • RMCF0805JT47K0
    RMCF0805JT47K0
    General Purpose Thick Film Standard Power and High-Power Chip Resistor 47 kOhms ±5% 0.125W, 1/8W Chip Resistor 0805 (2012 Metric) Automotive AEC-Q200 Thick Film Features: - RMCF – standard power ratings - RMCP – high power ratings - Nickel barrier terminations standard - Power derating from 100% at 70ºC to zero at +155ºC - RoHS compliant, REACH compliant, and halogen free - AEC-Q200 compliant
    jharwinbarrozo
    1.2M
  • 875105359001
    875105359001
    10 µF 16 V Aluminum - Polymer Capacitors Radial, Can - SMD 30mOhm 2000 Hrs @ 105°C #commonpartslibrary #capacitor #aluminumpolymer #radialcan
    jharwinbarrozo
    1.2M
  • CTL1206FYW1T
    CTL1206FYW1T
    Yellow 595nm LED Indication - Discrete 1.7V 1206 (3216 Metric)
    jharwinbarrozo
    1.1M

nrf52_tilt_sensor_flat_battery_Modules_approach2

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