Below is the minimum necessary to start creating watch faces for various Amazfit watches. This explanation is especially suited for the Bip-U model, for which there is almost nothing on the internet. Most of the steps are applicable to other models such as GTS and GTR in their different varieties.
The watch faces of various Amazfit models use the same app for this purpose found on the Huami website (Xiaomi, Amazfit and Zepp watches are manufactured by Huami).
First you have to register in Huami as a developer (description at https://amazfitwatchfaces.com/forum/viewtopic.php?t=2090)
To do this, you have to register at https://dev.huami.com/#/user/register/reg without completing step 2, unless you want to enter several very personal data (passport copy, photo, etc.) and wait from 4 to 6 days for approval.
Once you have the account (activated or not), you can access the watch face app at https://dev.huami.com/watchface/index.html#/create It's in Chinese, but there is a drop-down menu on the right of screen where you can select English (if you don't see it, make the browser window as big as possible to make it visible).
If you have registered, but have not completed step 2 of the registration, you will see a message in Chinese that says that you do not have permission. Nevertheless, you can still enter the app by opening a javascript console (F12 in most browsers and then looking for the console tab) and entering the following code:
localStorage.setItem ('examineType', '2');
This has to be done every time you enter the app, but you can install the tampermonkey extension in the browser (Chrome and surely others) and add the following code in tampermonkey to run it automatically each time you enter the Huami developer page:
// == UserScript ==
// @name Amazfit watch editor
// @namespace http://tampermonkey.net/
// @version 0.1
// @description Enables the editor without giving up ID
// @author AnyBody
// @match https://dev.huami.com/watchface/*
// @icon https://www.google.com/s2/favicons?domain=huami.com
// @grant none
// == / UserScript ==
(function () {
localStorage.setItem ('examineType', '2');
}) ();
Once inside the application, choose the model and resolution of your smartwatch from the drop-down menu.
The Bip-U does not appear in the drop-down list, but it is equivalent to the LITE type with 302x320 resolution.
You must upload any 202x214 image as a thumbnail to go on. For this you must create any .png image of that size using your favourite photo editor. This image is the one that will later appear on your watch when you hold it down to be able to change the face. You may change it when you have finished your watch face, and it is easy from the creation app.
Once inside the app, you can save the watch face and download the .bin with the export button. Some details about the watch face edition follow.
In the various menus you will find all the elements that you can include in your watch face, starting with the background.
For each item you must upload an image or set of images. In a later section you can see how to get images for the elements of the watch face. In elements such as numbers, all 10 images can be selected at the same time, thus creating a slice. Later, that slice can be reused in other elements that need the same type of number.
The elements marked with * are mandatory and you have to put something even if they are not used at all. When exporting, it will notify us if we have missed anything.
There are sets of images that are displayed in different ways, such as those of weather; if you want to show them superimposed in the same place you have to choose Display Method> Single Display (instead of Continuous Display). If some items are not displayed when placing the watch face in the watch, probably we have to change the Display Method.
Finally we export the watch face and a .bin is generated. The .bin file can integrate into the clock as explained below.
The first thing to do is to download any watch face from the Zepp application store on your mobile. Any watch face can serve as we are going to replace it with ours.
We then connect the mobile to the PC and open a file explorer to access the files on the mobile (for Android 11 or higher see below, as this explorer method probably does not work).
The watch faces downloaded from the Zepp store are stored in a subdirectory under /sdcard/Android/data/com.huami.watch.hmwatchmanager/files/watch_skin_local/ (Instead of / sdcard / it could be something else, depending on the mobile model, Android version, file explorer, etc.)
We look for the watch face that we have just downloaded and we replace the .bin file with ours: IT IS VERY IMPORTANT THAT OUR .BIN FILE HAVE EXACTLY THE SAME NAME AS THE ONE WE ARE REPLACING.
Next, we open the Zepp app on the mobile and synchronize the face that we had downloaded with the watch (the photo that appears is the one of the face that we have downloaded, not ours, but it does not matter, since what matters is the .bin file).
It is possible that, depending on the version of the mobile operating system, there is no permission to modify the files of the watch faces. The first thing to do is put the mobile in developer mode and to have USB debugging enabled (search the internet for how to do it).
You can then install and run Android Studio.
In Android Studio there is a "Device File Explorer" in the top menu "View> Tool Windows". With that we can now access the directory mentioned above to include our watch face.
You can also use AdbLink which is simpler to install than Android Studio, although the integrated browser is too basic and too cumbersome.
Everything that appears in the watch face is an image, preferably in .png with transparency.
Resources can be obtained by unpacking GTR 47 watch faces from https://amazfitwatchfaces.com/gtr/fresh?compatible=47mm or also GTS where the screen is square. These watch faces have elements whose images fit well into Bip-U.
Once you have the .bin of the model you like, you can unpack it with the following tools:
If the .bin is compressed (it usually is) it must be decompressed with: https://github.com/amazfitbip/resunpacker_qzip
Once unzipped it can be unpacked with: https://github.com/amazfitbip/py_amazfit_tools/releases/tag/v0.2-beta
The latter generates a directory with resources that we can use in our watch face.
There are Windows binaries for both tools, so it is not necessary to download the entire repository, just the binaries.
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