Hi, I am using the said RTC module for a project. Since it does not have a battery requirement due to installed supercapacitor, I was wondering if someone has tested this module.
I know the product page says it can last for up to a week, but I’m interested in knowing if someone has experimentally tested claimed for reliability.
Would you suggest I go for another RV3028 with battery if I want to make this project low maintenance (for if I cannot charge the RTC for minutes before use in the future)?
I am not entirely sure if the module has been empirically tested, though I would assume it was tested before release multiple years ago.
The supercapacitor can provide power for a length of time, but that time is based on a couple of factors, namely:
Vcc (the cap will charge to Vcc-0.3V, due to an internal Schottky diode)
Minimum supply voltage. which for this device is in the range of 0.9V-1.2V
Current consumption of the device. It is designed to be low current, hence the long-lasting backup power.
Regarding your question about using another RTC, what exactly is the project used for? This RTC isn’t necessarily intended for use without a battery, it just has the capability to run without one as a backup. In order to run for a week from the supercapacitor, the device must be connected to an external power source for approximately 1hr.
The board has access to an external interrupt that activates when it switches to backup power. You may be able to create a system to determine if the device is on backup. For example, activate an LED (possibly blinking very slowly and dimly to reduce power consumption) when the device switches to backup, thus notifying you that the battery must be switched.
I just want an external RTC module to put a timestamp on images and saves them when clicked.
This is super useful, thanks for letting me know! I was only debating whether I should keep things simple and use a button-cell based RTC instead, so I don’t have to worry about charging the supercapacitor-based module
