Storage Link — quick guide

Storage Link is an ESP32-based module that turns an addressable LED strip into a filament spool storage indicator and can optionally publish temperature and humidity from an SHT31 sensor.

• Connects to Wi-Fi and links the device to portal.idryer.org.
• On command from the cloud or local app, highlights a spool slot for a specified time in a specified color.
• Publishes temperature and humidity when an SHT31 sensor is installed.

Knowledge about the storage rack and spools lives in the external application. The firmware works as a simple executor: "highlight slot N with color C for T seconds". This lets you attach the strip to any rack and describe it in the portal independently of the firmware.

Supported boards

Board
ESP32-C3 DevKitM-1	✅
ESP32-C3 Super Mini	✅
Seeed XIAO ESP32-S3	✅
Waveshare ESP32-S3-Zero	✅

Any other ESP32-C3 or ESP32-S3 board can be used if it has a free GPIO for the LED strip data line and a pair of GPIOs for I2C. Check the manufacturer's pinout.

Wiring

Never connect or disconnect wires while power is applied.

Storage Link controls the strip through one signal GPIO (DATA) and can optionally read the SHT31 over I2C.

LED strip power

The strip and ESP must be powered from a supply rated for the strip's actual load.

• On many ESP boards, the 5V (VBUS) pin is connected directly to the USB connector. If your USB power supply has enough current headroom for the strip load, you may power the ESP and strip in parallel from it.
• If there is not enough current headroom, power the strip from a separate 5 V PSU. The PSU ground must be connected to the ESP GND; without a common ground, the DATA signal will not work.

In both cases, set psu_ma in the menu to the current your 5 V power supply can actually deliver. This is not the desired current, but the PSU's rated output. FastLED uses this value to limit total brightness so the limit is not exceeded.

Good assembly practices

These parts are not required for startup, but they eliminate typical addressable strip issues such as skipped pixels, first LED glitches, and voltage drops during power-on.

• Resistor in the DATA line. Place a 300-500 Ohm resistor (typically 390 Ohm) in series between the ESP GPIO and the strip DIN, physically as close to the strip as possible. It damps signal reflections and protects the first chip on the strip.
• Electrolytic capacitor on power. Place a 1000 uF capacitor rated for 16 V between +5V and GND at the strip power input (25 V is also fine, 10 V is the minimum). It smooths current surges during sharp turn-ons.

• Common ground wire sized for PSU current. The ESP-strip-PSU ground wire must be sized for the strip's peak current. A guideline for short wires (up to ~1 m):

  PSU current	Cross-section	AWG
  up to 3 A	0.5 mm²	AWG 20
  up to 5 A	0.75 mm²	AWG 18

  Use the same cross-sections for the +5V line to the strip. For long strips, feed power from both ends.

Signal connections

GPIO values depend on the board.

ESP32-C3 DevKitM-1 and ESP32-C3 Super Mini

ESP	Purpose
GPIO4	addressable strip DATA
GPIO8	SDA (SHT31, optional)
GPIO9	SCL (SHT31, optional)
GND	common ground with strip and PSU

Seeed XIAO ESP32-S3

ESP	Purpose
GPIO2	addressable strip DATA
GPIO5	SDA (SHT31, optional)
GPIO6	SCL (SHT31, optional)
GND	common ground with strip and PSU

Waveshare ESP32-S3 Zero

ESP	Purpose
GPIO4	addressable strip DATA
GPIO8	SDA (SHT31, optional)
GPIO9	SCL (SHT31, optional)
GND	common ground with strip and PSU

Board pinouts

ESP32-C3 Super Mini:

Waveshare ESP32-S3-Zero:

Optional SHT31 sensor

The sensor is needed only if you want this device to publish temperature and humidity. Storage Link starts and works with the strip the same way with or without the sensor. If the sensor is not installed, temperature and humidity are simply not sent.

• Bus: I2C on the corresponding board's SDA/SCL.
• Address: 0x44 or 0x45 (the firmware detects it automatically at startup).

Flashing via web flasher

The web flasher is available at install.idryer.org.

1. Connect Storage Link to a computer USB port.
2. Open install.idryer.org and click Storage Link.
3. Select your board variant.
4. Click Connect and select the serial port. If the device is not detected, hold the BOOT button on the board and briefly press RST.
5. Click Install. The flasher will write the firmware.
6. When flashing is complete, the Wi-Fi setup wizard will open.

Wi-Fi setup

After flashing, the Improv wizard opens automatically in the Serial port.

1. Enter the SSID and password for your 2.4 GHz network.
2. Wait for the Connected status.

If the wizard did not open, unplug USB and connect again with Connect without flashing again.

ESP32-C3 and ESP32-S3 support only 2.4 GHz Wi-Fi. 5 GHz networks do not work.

Linking to the portal

1. On the flasher page, click Connect and Claim. A claim command will be sent to the device.
2. After a few seconds, a PIN will appear on the page. The PIN is valid for about 5 minutes.
3. Open portal.idryer.org -> Add device -> enter the PIN.
4. After successful linking, the device will appear in the list as online.

If the PIN does not appear or linking fails, repeat the claim, or delete the device in the portal and try again.

LED strip setup

Parameters are set through the device configuration menu. Some are applied immediately, while others only after reboot.

Parameter	Values	Default	Applied
led_count	1..300, step 1	120	immediately
psu_ma	500..20000 mA, step 100	5000	immediately
strip type	selected from available menu options	WS2812B	after reboot
color order	GRB, RGB, BRG, BGR	GRB	after reboot
language	ru / en	en	immediately

Basic checklist after the first startup:

1. Set led_count to the actual number of pixels on the strip.
2. Set psu_ma to the rated 5 V PSU current in milliamps.
3. Select the type of strip you have installed.
4. Select the color order. The default is GRB. If red and green are swapped or the color is wrong, try the other options.
5. Reboot the device; strip type and color order are applied only after reboot.

Expected result

• After claim, the device is visible online in the portal.
• A highlight command from the portal or app lights the selected slot on the strip for the specified time. A new command turns off the previous slot and lights the next one.
• If an SHT31 is installed, temperature and humidity are regularly updated in the portal.
• If no SHT31 is installed, climate readings are absent; this is normal.