The regulator every ESP32 secretly needs

A 3.3V supply for an ESP32: an LD1117 regulator with enough capacitance to ride out the radio's current spikes, plus a power LED.

Power

Component side layout of The regulator every ESP32 secretly needs on a perfboard 16 by 28 holes — 16 × 28 holes · 8 parts · 12 wiresOpen the build sheet

Free build sheet

The parts, every wire with its length and bend points, a bend guide, both sides of the board and checkboxes to track your progress. Print it or keep it open at the bench.

Open the build sheet

What you need

8 parts on a perfboard 16 × 28 holes, plus hookup wire.

Qty	Part	Where to buy
2	Electrolytic Cap10uF C1, C2	Buy Electrolytic Cap on Amazon
1	Ceramic Cap100nF C3	Buy Ceramic Cap on Amazon
1	Power Input (2-pin) J1
1	Signal+Power Header (3-pin) J2
1	LED LED1	Buy LED on Amazon
1	TO-220 Q1
1	Resistor (axial)330 R1	Buy Resistor (axial) on Amazon

Check every pin against the datasheet of the exact part in your hands before wiring.

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Cut list

12 wires, 305 mm (12.0 in) in total, in the order the build sheet cuts them. Wire numbers match the build sheet. Each length includes 5 mm per end to go through the hole.

Wire	Colour and net	Route	Length	Bends
12	BlackGND J26 → D24	J26 → D24	30mm	20mm (90°)
6	Black3V3 I15 → H25	I15 → H25	38mm	8mm (90°)
5	Blue3V3 J16 → L16	J16 → L16	15mm	Straight
11	BlueGND I18 → J24	I18 → J24	28mm	20mm (90°)
10	GreenGND J17 → L17	J17 → L17	15mm	Straight
4	Green3V3 E16 → H16	E16 → H16	18mm	Straight
7	RedGND E5 → I5	E5 → I5	20mm	Straight
1	Red5V D3 → J3	D3 → J3	25mm	Straight
3	White3V3 C16 → C11	C16 → C11	23mm	Straight
9	WhiteGND E10 → H17	E10 → H17	35mm	23mm (90°)
8	YellowGND F4 → D9	F4 → D9	28mm	18mm (90°)
2	Yellow5V C4 → C12	C4 → C12	30mm	Straight

About this build

An ESP32 runs on 3.3V, not 5V, and it pulls sharp current spikes every time the radio transmits. So it needs a 3.3V supply with real capacitance on both sides of the regulator.

This board is an LD1117V33 in a TO-220. 5V comes in on a 2 pin input with a 10uF cap, and the 3.3V output gets a 10uF and a 100nF. A 330 ohm resistor and an LED show when the output is up, and a 3 pin header carries 3.3V and ground out to the ESP32.

One trap: the LD1117 doesn't share the 7805's lead order, so you can't drop one into the other's footprint. The build sheet and the ST datasheet give the wiring.

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