Today, I want to share some “unconventional” yet extremely useful tricks in embedded development that seasoned veterans rarely disclose!
First Technique: Hardware Issues? Pass the Buck First!If you encounter a program crash, don’t rush to modify the code! First, check if the hardware layout matches the schematic. Our project was delayed last time because a capacitor was soldered in the wrong position. When communicating with the PM, be tactful: “The delay in this functionality is mainly due to hardware design adjustments, and we are closely collaborating with the hardware team” (adding a coffee cup emoji makes it more natural). Remember to follow up on the solution; after all, passing the buck is just a tactic, solving the problem is the goal.
Second Technique: Install a ‘Backdoor’ on the HardwareUsing the devmem command to directly manipulate registers is like installing a portal on the hardware! For example:# View the value of register 0x50300000devmem 0x50300000 32# Modify the register value (use with caution!)devmem 0x50300000 32 0xdeadbeefLast time, while debugging the camera driver, I discovered a hidden test mode from the hardware vendor using this method!
Third Technique: Code Assembly Like LEGOWrite sensor drivers as struct modules:typedef struct { int (*init)(void); int (*start)(void);} sensor_driver;// Implementation from Vendor Asensor_driver sensor_A = {init_A, start_A};// Implementation from Vendor Bsensor_driver sensor_B = {init_B, start_B};// Switch by direct assignmentsensor_driver *current = &sensor_A;Changing sensors is like swapping LEGO blocks; in the last project, switching suppliers only required changing 3 lines of code!
Fourth Technique: Pointer Safety Triple CheckDeclare and immediately assign NULLAlways check for NULL before useSet to NULL immediately after freeingint *data = NULL;if (data) { /* Safe Zone */ }free(data);data = NULL; // This line can save your life!Last time, a wild pointer caused the system to reboot, and it took three days to find out it was because I didn’t set NULL after freeing!
Fifth Technique: Log Level Black TechnologyAutomatically adjust log levels based on the environment:#ifdef DEBUGlog_level = LOG_DEBUG;#elselog_level = LOG_ERROR;#endifIn production, only errors are logged, while in development, debug information is flooded. Coupled with log rotation, my mom no longer has to worry about my hard drive being filled up!
These techniques may seem “unorthodox”, but they are truths verified through blood and tears. What bizarre issues have you encountered in development? Feel free to vent in the comments.
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