Hello friends! I have bought a 4 in 1 MAX7219 display, which seemed more convenient because is a single pcb and needs no frame. My project is a smart clock with DS3231, active buzzer and IOT forecast. I started by using an Arduino UNO R3 to drive it and I builded my own scrolling functions using LedControl library. Now I am using ESP32 Dev module because is faster. Everything works fine after turning on, but after a time one of the 4 devices simply stops. Sometimes even two of them stop. Program still run corectly, text is still scrolling. If i wait enough sometimes they come back, sometimes not. I haven’t had this issue with the UNO R3 from what I remember. I’ll come back with pictures and code.
I attached the code, because it cannot be embedded due to its large size. Main functions which call ROWSET are scrollText() and setText(). Also I atached some pics with the working project. I mention that I soldered two caps 1nF and 10nF near the power supply pins (visible in third picture) but they don’t make any difference. I will come again with pictures when fails (one or more matrix turns off).
code.ino (15 KB)
Forgot to mention that the power line for the display comes from the VIN pin from ESP32 dev module, which is rated at 4.7V from what I measured. Current drawed by the display is somewhere between 70-200mAh (measured with amateur ordinary instrument). ESP32 modules is powered from Laptop USB 3.0.
I'll explain again (I feel that I was confuse) the problem: After a while of working properly, one or two MAX devices from the total of 4 simply turns off and do not lit anymore. If I reset, they are working fine for another period of like 30-60 min.
PS. The ESP32 is always connected to WiFi router.