OPPO Smart Watch 41MM WiFi (Black) Review and recommendation

Key features

  • 41MM (1.6-inch) Rigid AMOLED display with 320×360 screen resolution.
  • 300mAh lithium Polymer Battery | 14 days of Battery Life | VOOC Flash Charging.
  • Built in GPS | Google Assistant |Heart rate monitoring |Sleep monitoring |Get Up Reminder|Guided breathing exercises

Its almost 2 weeks I purchased OPPO 41mm smart watch. I was fond on the look and feel of the watch and the cost at which a smart phone with Apple equivalent design and features offered. Hence gone for the same. After unboxing I felt I was cheated due to the battery life it showed as 2 hours to drain for a fully charged to empty by the app. Right now I will say you just need to erase all your assumptions on battery life expectations and adjust to it. These are the things I did to save battery life.

  1. Reset to defaults.
  2. Upgrade the software to latest. (After this the battery life increased from 2 to 12 hrs)
  3. Disabled the hand gestures.(12 hrs to 18 hrs)
  4. Don’t install any extra app other than compass and GPS navigator. Google music its up to your style. Should not expect much battery life with those applications.
  5. Set the world clock as watch face. Instead of other clocks I set alarm, steps, heart points and distance covered.
  6. Keep unwanted sensors off.
  7. Wifi Off. I wanted wifi so I didn’t, but it seems like it will save lot of battery life.
  8. Keep location of – Saves a lot of battery.
  9. Modify the notifications – Select only those apps which are genuinely use.

I liked always on feature. But heard with 41mm(300mAh) we can achieve 24+ hours battery life. When it comes very less battery the watch will enable automatically the battery saver feature, which I didn’t test to see how long it hold, but found to be a useful feature which will make sure your watch will be up till you find a charging point in a remote village. One thing I felt not to return the watch is its fast charging, 30 minutes to charge from 40% to 100%. So I never felt the battery draining a problem. The combination of fast charging and battery saver saved Oppo. I recommend go ahead and buy it. If you change your life style of charging and expectations, this is a good addition.


  • You can attend the call via watch, speaker is pretty good.
  • Square in design so maximum use of the screen.
    No issues using in sunlight.
  • Impressive response with user interface and touch.
  • Amazing Display.
  • Very comfortable on the wrist.
  • Good Fitness tracking.
  • Power saving mode helps to keep the watch for long time.
  • Fast charging 40-100% in less than 30 minutes.


  • Battery life ( you cannot use all the smart watch features and expect it to have battery life).
  • Even though blue tooth is used to sync the watch and mobile. Apps like Weather are not synced with blue tooth and requires wifi.

Quick summary on shared libraries

Shared libraries are reusable libraries which can be used by multiple applications at the same time. The advantages of shared libraries are

  1. Can be loaded at application start or on demand at run time.
  2. Can be upgraded separately and reloaded.

Only disadvantage compared to statically linked library is, there is an overhead for loading the library and resolving the symbols at run time.

In case of loading during application start, the loader will load the library into process virtual address space and resolve before the application is launched.

In case of loading dynamically the same can be achieved with the respective system library apis when in need..

Windows it will be a dynamically linked library(*.dll) and uses the same PE format as windows executable.

Linux it will be a shared object(*.so) and uses the ELF format as a normal linux executable.

In linux use the -shared gcc option to create a shared object. if your library name provided is, the linux linker will create it as

While statically linking, the option -labc should be provided to link with the same.

If you are using dynamic linking, you need to use dlopen(3) ,dlsym(3) and dlclose(3) apis to load, access the symbol and unload the library.

Sample codes


#include <stdio.h>
#include “call_lib.h”

int main(int argc, char * argv[])
printf(“In application\n”);

return 0;


int call_lib(int num);


#include <stdio.h>
#include “call_lib.h”

int call_lib(int num)
printf(“passed value is %d\n”, num);

return 0;

To compile the library code
gcc -shared -fPIC -o library.c

To compile the application code
gcc -o sample -L /home/yogi/libs -lrary application.c

Running the executable

set first the library path

$export LD_LIBRARY_PATH=/home/yogi/libs:$LD_LIBRARY_PATH
$ ./sample
In application
passed value is 3

Source: Working with Shared Libraries | Set 1 – GeeksforGeeks

Interesting Facts about Macros and Preprocessors in C – GeeksforGeeks

One of the phase in compilation is pre processor replacement. In C programming there are multiple pre processor directives. The common one are include and define. There could be other directives like pragma and others which are compiler supported ones and may not be supported in all the compilers.

#include directive can be used to include the header files. If the header files are included <> brackets, the header file will be searched in the standard include paths mentioned as part of compilation with -I option. If the header files are used within double quotes “”, the current path will be used to search first before searching the standard paths.

#define will replace all the tokens with the values defined for the token.

Source: Interesting Facts about Macros and Preprocessors in C – GeeksforGeeks

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