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Check that none of the unconnected pins require pull-up or pull-down resistors t...
2y
Given the description of the project, it seems no information about individual pin requirements for pull-ups or pull-downs was provided. However, for many components, general practices apply.
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I2C bus (SDA / SCL): The I2C pins, specifically SDA (Data line) and SCL (Clock line), typically need pull-up resistors since it's an open-drain bus. Your project seems to have some I2C communication because it includes both SDA and SCL nets. If you don't already have pull-up resistors connected to these lines on your schematic, I recommend connecting them.
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Enable (EN) pins: Normally, for digital ICs, if an Enable (EN) pin is not expected to be driven by another GPIO, it's a good practice to pull it either to ground (for active high enable) or to Vcc (for active low enable) to have defined behavior.
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Reset pins: Reset (RST) pins are typically active-low and are often pulled up to avoid accidental resets.
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Communication lines such as USB D+/D-: These lines normally come with their pull-up / pull-down circuitry on a connected device. So, if there's an external device connected on those lines, you probably won't require additional pull-up/downs. You just have to match the impedance for these lines.
Still, the decision strongly depends on each specific design requirements. You should check the datasheets of your components (mainly U1 and IC2) to verify the kind of connection each pin requires.
Please keep in mind, pull-up and pull-down resistors can take a variety of forms depending on the context, which might not always be obvious based on a generic schematic. It's also considered good practice to connect any un-used digital pins to a known state (either high, low, or via a pull-up or pull-down), rather than letting them float, as this can lead to an unpredictable behavior.
2y
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6
to connect LED1 correctly, what value should I choose for the R6?
2y
To suggest a suitable resistance for R6, we need to know the desired forward current (I_f) for LED1 (the LTST-C191KGKT). Unfortunately, I don't have a datasheet excerpt for the LED and can't provide that detail.
However, assuming typical values, most standard LEDs have forward voltage (V_f) around 2.0V to 2.2V and operate at around 20mA (0.020A) forward current.
Here is how to calculate the resistance:
The IC2 (TPS62130RGTR) regulator provides 3.3V, and the forward voltage of the LED would be around 2.0-2.2V. Using Ohm's law, resistance (R) is:
R = (Voltage of IC2 - Forward voltage of the LED)/desired forward current of the LED
Assuming the forward voltage V_f of the LED is 2.1V and the desired forward current I_f is 20mA, and the output voltage of IC2 is 3.3V,
R = (3.3V - 2.1V) / 0.020A = 60 ohms
You should pick the standard resistor value of 68 ohms for R6.
Please verify this with the actual forward voltage and forward current from the LED manufacturer's datasheet. And remember, LEDs should be connected in the correct polarity to prevent damage: connect the anode (A) of LED1 to the positive side (output of R6), and the cathode (K) to the negative side (GND).
2y
Datasheet URL is provided in the description you can find
2y
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2y
Datasheet URL is provided in the description you can find
2y
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2y
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11
12
R3
Resistance
5.1kΩ
GND
GND
LED
3V3_USB
SCL
SCD41_EN
R4
Resistance
5.1kΩ
USB_D+
3V3_EN
USB_D-
LED
C9
Capacitance
22uF
3V3_EN
SDA
USB_D+
1V8_EN
SDA
SCL
SGP41_EN
USB_D-
SHT40_EN
GND
R10
Resistance
10kΩ
R6
Resistance
200 Ω
C6
Capacitance
100pF
SW1
J1
C2
Capacitance
10uF
U1
IC1
+5V
R11
Resistance
10kΩ
R7
Resistance
100kΩ
3V3_USB
3V3_USB
3V3_USB
C7
Capacitance
100pF
LED1
L2
Inductance
2.2uH
R2
Resistance
100KΩ
D2
Capacitance
12pF
R12
Resistance
Resistance
R1
Resistance
Resistance
Reviews
- Wirelessly connects nets on schematic. Used to organize schematics and separate functional blocks. To wirelessly connect net portals, give them same designator. #portaljharwinbarrozo43.0M
- 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 #powerjharwinbarrozo11.4M
- 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 #CommonPartsLibraryjharwinbarrozo1.5M
- 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 #CommonPartsLibraryjharwinbarrozo1.5M
- 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 #CommonPartsLibraryjharwinbarrozo15.8k
- An electrical connector acting as reusable interface to a conductor and creating a point where external circuits can be connected.Terminal
- 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 compliantjharwinbarrozo1.2M
- 10 µF 16 V Aluminum - Polymer Capacitors Radial, Can - SMD 30mOhm 2000 Hrs @ 105°C #commonpartslibrary #capacitor #aluminumpolymer #radialcanjharwinbarrozo1.2M
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Properties
Properties describe core aspects of the project.
Pricing & Availability
Distributor | Qty 1 |
|---|---|
Digi-Key | $18.68–$20.29 |
LCSC | $1.32 |
Mouser | $19.32 |
Controls
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okanaraz
copilot
SCD41_ENconnected to theU1:PA221V8_ENconnected to theU1:PA27~RESET~ofU13V3_ENconnected to theU1:PA28ENof theIC2SCD41_EN: This line doesn't appear to be connected to any resistors, so no pull-up or pull-down resistor appears to be present.1V8_EN: This line doesn't appear to be connected to any resistors, implying there is no pull-up or pull-down resistor associated.~RESET~: Reset line is connected through the resistorR7. We can't determine if it's a pull-up or pull-down resistor without knowing the other components connected to the~RESET~line or the circuit's Vcc.3V3_EN: This line isn't connected to any resistors, suggesting there's no pull-up or pull-down resistor involved.ENofIC2: This pin seems to be connected directly to the+5Vpower supply without a resistor, meaning there isn't a pull-up or pull-down resistor for this signal.SCD41_ENnet.1V8_ENnet.~RESET~configuration to confirm whetherR7is used as a pull-up or pull-down resistor. If not, add one as needed.3V3_ENnet.ENpin ofIC2is directly connected to power, which means it's always enabled. If adjustable enabling is required, consider adding a transistor switch controlled by a microcontroller GPIO, or a pull-up resistor if the used part supports enable via pulling up to Vcc.