My CYD Clock

A clock for the Cheap Yellow Display. Big numbers, tap for the weather, and a settings page on your own network.

You need Chrome or Edge on a computer. This page talks to the board over its USB cable, and only those browsers can do that. Firefox and Safari cannot, and neither can phones or tablets.

Install it

Plug the board into your computer with a USB cable that carries data, then pick your board below. Charge-only cables look identical and will not work.

2.8 inch

ESP32-2432S028R · 240 x 320

Your browser cannot do this. Use Chrome or Edge on a computer. This only works over a secure connection.

3.2 inch

ESP32-2432S032R · 240 x 320

Your browser cannot do this. Use Chrome or Edge on a computer. This only works over a secure connection.

3.5 inch and 4.0 inch

ESP32-3248S035R · 320 x 480 · the 4.0 inch board uses the same panel

Your browser cannot do this. Use Chrome or Edge on a computer. This only works over a secure connection.

The model number is printed on the back of the board. If you pick the wrong one the screen will stay black or show nonsense, which does no harm: come back and install the right one.

What happens when you click

  1. Your browser asks which device to connect to. Pick the one that mentions CH340, CP210x, USB Serial or a COM number.
  2. It offers to erase the board first. See below.
  3. It writes the firmware, which takes about a minute.
  4. The clock starts up and asks you to set up WiFi.

Should you tick Erase?

Installing this for the first time: yes. Updating a clock you already set up: no.

Erase wipes the whole memory chip. On this board that is the firmware, which is about to be replaced anyway, and a small area holding the clock's settings and its copy of your WiFi details. Nothing else lives there. Ticking it means the clock comes up knowing nothing and asks you to set up WiFi again, exactly as it would out of the box.

Leaving it unticked replaces the firmware and keeps your WiFi and settings, which is what you want for an update.

People warn against it because on some other devices that memory holds calibration numbers written at the factory that cannot be recovered. These boards have nothing like that. Your board's own serial number and network address are not stored there either, so erasing cannot touch them.

It is also worth ticking if a clock starts behaving oddly after an update: it clears out any leftovers from an older version. You will have to set up WiFi again afterwards.

If no device appears in that list, your computer does not have the driver for the board's USB chip. Look at the small square chip next to the USB socket: search for a CH340 driver or a CP210x driver to match it, install it, and unplug and replug the board.

Setting up the clock

The first time it starts, the clock has no WiFi, so it makes its own network for you to find it on.

  1. The screen says to join a network called My_CYD_Clock. It is open, with no password.
  2. Join it on your phone. A setup page should open by itself. If it does not, open a browser and go to the address shown on the clock.
  3. Pick your own network from the list, type the password, and press Connect.
  4. The clock restarts and shows you the address for its settings page, where everything else can be changed.

Some phones need mobile data turned off before that setup page will open on its own, because the phone works out that this network has no internet and quietly goes back to mobile. Typing the address by hand always works.

Afterwards

Touch and hold the screen to see the clock's address on your network, then browse to it for the settings: colours, clock face, time zone, weather location, alarms and brightness.

If the colours look like a photographic negative, tick Invert colours under Time Display and save. Some panels need it.