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Public Green Flubber
Properties
Properties describe core aspects of the project.
Pricing & Availability
Distributor | Qty 1 |
|---|---|
Digi-Key | $6.07–$7.23 |
LCSC | $8.28 |
Mouser | $4.28 |
Controls
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quaeke
copilot
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Voltage Regulator (U2): An LM1117-3.3 or similar, which can output 3.3V at up to 800mA, enough to power the ESP32 and some additional components.
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Capacitors:
- C1 (Input Capacitor): 10 µF, electrolytic, for input decoupling.
- C2 (Output Capacitor): 10 µF, electrolytic, for output stabilization.
- C3, C4 (Bypass Capacitors): 0.1 µF, ceramic, for noise reduction on the power supply lines.
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Optional: Additional filtering or protection components like ferrite beads or a TVS diode for protecting against voltage spikes.
Design Steps:-
Select a Power Source:
- Can be a USB power supply (5V), a battery pack, or another regulated power source.
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Connect the Voltage Regulator:
- Input: Connect the power source (+) to U2:Vin (Pin of your voltage regulator, exact naming depends on the specific regulator datasheet).
- Ground: Connect the power source (-) to U2:GND and ESP32-WROOM-32:GND (Pins 1, 15, 38, 39).
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Add Capacitors:
- Input Capacitor (C1): Connect one side to U2:Vin and the other side to GND.
- Output Capacitor (C2): Connect one side to U2:Vout and the other side to GND.
- Bypass Capacitors (C3, C4): Connect C3 near the ESP32-WROOM-32:VDD (Pin 2) and another near any peripherals you are powering. Connect one side to the 3.3V supply line and the other to GND.
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Power to ESP32:
- Connect U2:Vout to ESP32-WROOM-32:VDD (Pin 2).
Connection Summary:- Connect U2:Vin to your power source (+).
- Connect U2:Vout to ESP32-WROOM-32:VDD (Pin 2), C2:1, and C3:1.
- Connect all GNDs together: ESP32-WROOM-32:GND (Pins 1, 15, 38, 39), C1:2, C2:2, C3:2, C4:2, and your power source (-).
Assumptions Made:quaeke
copilot
- C1 (Input Capacitor): Use a 10 µF, ceramic capacitor with an appropriate voltage rating (at least 1.5x the input voltage for safety). Be mindful of the capacitor's voltage rating, especially if your input voltage approaches or exceeds the common 6.3V or 10V ratings of many SMD ceramic capacitors.
Adjusted Design Steps:- Capacitors: Replace the electrolytic capacitor suggestion with ceramic capacitors for both input and output stabilization.
- C1 (Input Capacitor): Choose a 10 µF, X5R or X7R dielectric ceramic capacitor for better performance across temperature ranges. Connect one side to U2:Vin (the input pin of LM1117-3.3) and the other side to GND.
- C2 (Output Capacitor): Similarly, use a 10 µF ceramic capacitor. Although the LM1117 datasheet might recommend an electrolytic capacitor for stability, modern ceramic capacitors, especially those with X5R or X7R dielectric, are typically sufficient for such low-dropout (LDO) applications.
Connection Summary with SMD Recommendations:quaeke
copilot
- Input Voltage Range: It supports an input voltage range of 1.8V to 5.5V, covering the entire range of a single-cell LiPo battery from fully charged to fully discharged.
- Output Voltage: It can be configured to output a stable 3.3V, which is ideal for the ESP32.
- High Efficiency: It offers high efficiency across a wide range of load currents, which is beneficial for battery-operated devices.
- Package: It comes in a small QFN package, which is suitable for compact, SMD-based designs.
Circuit Design Adjustments:-
TPS63020 Connections:
- VIN Pin: Connect to the positive terminal of the LiPo battery.
- GND Pin: Connect to the negative terminal of the LiPo battery and the ESP32-WROOM-32's GND pins.
- VOUT Pin: Set to 3.3V following the recommended circuit configuration from the datasheet, and connect to ESP32-WROOM-32:VDD (Pin 2) and the input of any bypass capacitors you're using.
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Input and Output Capacitors:
- For the TPS63020, Texas Instruments recommends specific values for the input and output capacitors to ensure stable operation. Refer to the datasheet for these values, but typically a 10 µF ceramic capacitor on both input (VIN to GND) and output (VOUT to GND) should be sufficient for most applications.
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Feedback Components:
- The TPS63020 typically requires feedback resistors to set the output voltage. For a 3.3V output, you'll need to select resistor values as recommended in the datasheet.
Example Connection Summary with TPS63020:quaeke
copilot