LAB Docs
Browser flashing · Web Serial

Reflash a board over USB

Writes the complete bootable image — bootloader, partition table, NVS, application and OTA data — at the offsets the board expects. Nothing to install, nothing uploaded, no server involved.

A reflash erases the device. Every setting is wiped. On U1 and U2 that includes the CD KEY — copy it from Settings → System in the miner web UI first, because once lost it cannot be recovered from the firmware. S1 has no CD KEY, so there is nothing to save.

Only need to update a board that already works? Upload the OTA .zip from the firmware archive instead — it keeps your settings and, on U1/U2, the key.
Step 1 — pick your board

Three boards, three images

The images are not interchangeable. Pick the model printed on the device or its box.

Bitdsk S1 running on a CYD board

Bitdsk S1

v_1.5
CYD-2432S028 · ESP32 · no ASIC

Runs on the off-the-shelf CYD board. The ESP32 hashes by itself, so this is a desk display and a learning platform rather than a money maker. Firmware is MIT licensed and open source.

600k–800k H/s USB 5V 2.8″ touch
Source code & build guide on GitHub ↗ Open S1 flasher ↗
Bitdsk U1 Touch miner

Bitdsk U1 Touch

v_1.5.2
In-house · ESP32 · 200G class

Single-ASIC board with a 2.8″ touchscreen, 200G at about 10 W. The image ships without a CD KEY — re-enter your backup afterwards.

200G ≈10 W 2.8″ touch
Open U1 flasher ↗
Bitdsk U2 Touch miner

Bitdsk U2 Touch

v_1.5.2
In-house · ESP32 · 1100–1500G class

Different silicon from U1, 1100–1500G at 22–27 W. Shares the application image with U1; only the NVS partition identifies the model. Carries a CD KEY — re-enter your backup afterwards.

1100–1500G ≈22–27 W 2.8″ touch
Open U2 flasher ↗
Step 2 — before you connect

What you need

Requirements

  1. Desktop Chrome or Edge. Web Serial does not exist in Safari, Firefox or on mobile.
  2. A data-capable USB cable. Charge-only cables are the most common reason nothing shows up.
  3. U1 / U2: use the Flash Port. Those boards have a dedicated port for flashing — use that one, not the power port. No USB-TTL adapter is needed. On S1 the CYD's single USB port carries both power and serial.
  4. HTTPS. The browser blocks serial access on plain http:// pages.
  5. Nothing else holding the port. Close Arduino IDE, a serial monitor or any other tab that already has the board open.

Procedure

  1. Open the flasher for your board above and connect the USB cable.
  2. Pick the serial port that appears — the Flash Port shows up as a COM port.
  3. Keep Erase device checked for a clean install.
  4. Wait for Installation complete. Do not unplug while it writes.
  5. Join the device's AP and open the web UI. On U1/U2, re-enter your CD KEY there.
No COM port in the list? Check the cable is in the Flash Port and that it is a data cable, close anything else holding the port, and try another USB port. On Windows, if the device shows up with a warning in Device Manager, install the USB-serial driver for that chip — the CYD board used by S1 is CH340.
N5 series, N8 series and legacy boards are not flashed in the browser. Those devices update by uploading a .zip through the miner web UI — the files are in the firmware archive.
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