ESP CC Dimmer

A Wi-Fi constant-current LED dimmer running ESPHome.

Check https://github.com/flaviut/hardware/tree/main/esp_cc_dimmer for source code & the latest version.

Intended use

Designed to clamp onto wire shelving to dim a plant grow-light string. The 3D-printed enclosure bolts to two shelf nuts that slot behind the wire grid; two M3×20 bolts and nylock nuts pinch the shelf wire between box and nuts. The knob allows offline dimming.

Power supply

Requirements:

• 10–56 V DC, set by the NLDD-H input range (the board silk marks the 48 V design point).

• At least ~2 V above the LED string's forward voltage. Read your LED strip's datasheet.

• Current capacity ≥ your LED string + 50mA for the electronics.

How it works

• Power in (J2): 10–56 V feeds both the NLDD driver and an LX8015 buck that derives 3V3 for the MCU.

• Dimming: the ESP32-C3 drives the NLDD's PWM dim input at 50 kHz (LEDC) — high-frequency PWM keeps the driver silent.

• LED out (J1): constant-current string from the NLDD-H.

• Controls: EC11 rotary encoder (turn = ±5 % brightness, press = toggle).

• Sensing: VEML7700 ambient-light sensor on I²C (GPIO6/7).

Renders

PCB top	PCB bottom

Enclosure base	Lid

Knob	Shelf nut (×2)

Bill of Materials

Board: 68.25 × 52.0 mm, 2-layer.

Electronics

Refs	Qty	Value / Part	Package	Notes
U3	1	Seeed XIAO ESP32-C3
PS1	1	Mean Well NLDD-1050H		Any NLDD-350/500/700/1050H fits
U4	1	LX8015		3V3 for the MCU
U2	1	Vishay VEML7700	6-pin OPLGA	I²C ambient-light sensor
SW1	1	Alps EC11E15244G1	EC11 vertical	Rotary encoder with push switch
J1, J2	2	WJ15EDGRC-3.81-02P (clone) / Phoenix Contact MCV 1,5/2-G-3,81 — 1803426 (original)		Board-side pluggable headers (power in / LED out)
(mates J1, J2)	2	WJ15EDGK-3.81-02P-14-00A (clone) / Phoenix Contact MC 1,5/2-ST-3,81 — 1803578 (original)		Wire-side screw plug for each header
C2	1	100 µF 63 V	Radial Ø8 mm
C11	1	4.7 µF 100 V	1210
C8	1	10 µF	1210
C1, C3	2	1 µF	0603
R1, R2	2	4.7 kΩ	0603

Mechanical

Qty	Part	Notes
1	Enclosure base + lid	Print enclosure/esp_cc_dimmer_box.stl (both parts)
1	Dimmer knob	Print enclosure/dimmer_knob_textured.stl
2	Shelf nut	Print enclosure/shelf_nut.step
2	M3 × 20 mm bolt	Clamps box to shelf nuts
2	M3 nylock nut	—

Printing

• Knob (dimmer_knob_textured.stl): 0.12 mm layers, ironed top surface. The leaf texture was applied to the base model with bumpmesh.com (dimmer_knob.bumpmesh + leaves.png).

• Enclosure / shelf nuts: standard 0.2 mm, no supports.

Firmware

ESPHome config: esphome/esp-cc-dimmer.yaml. Provide wifi_ssid / wifi_password via secrets.yaml, then:

esphome run esphome/esp-cc-dimmer.yaml