Well, there are many points to consider—some outside the MCU, and others within it. If you send your circuit schematics here, I can list them out for you.

I have been unable to find any API or CPU reset status register that would allow reading the cause of the reset upon device power-up. Please advise.

The issue is solved.

My current SDK version is 1.4
The issue is that the Bluetooth Stack wakes the MCU up every 64 seconds (periodically ). Why is this happening?

@mars Do you mean that it is not possible to put the system into an indefinite sleep mode? I want the microcontroller (MCU) to wake up only when a specific event occurs (one that is not time-based).

I am using the sleep mode on the FR8003A chip. When I use the RTC wake-up feature, the Bluetooth stack functions correctly after waking up; however, when I use the button (GPIO pin) to wake the device, the Bluetooth stack malfunctions (the MCU wakes up upon pressing the button, but Bluetooth functionality is impaired thereafter). What is the issue? Could someone explain the correct procedure for entering and exiting sleep mode to ensure Bluetooth operates properly after wake-up?

According to the official FREQCHIP website (https://www.freqchip.com/fr800x), a new version of the SDK was released in August 2026; however, I could not find any release notes or a changelog for it. How can I find out about the changes or improvements made compared to version 1.4?

Thanks a lot. I also have another issue. When I put the MCU to sleep and enable the wake-up by a push button, the wake-up occurs but the Bluetooth stack does not work! I do the wake-up mechanism just like the sample projects, What am I missing here?

When I put the FR8003A in sleep mode with Bluetooth stack initialized and all wake-up mechanisms disabled, the MCU wakes up after 64 seconds. How can I prevent this unwanted wake-up? I want to wake it up only via a button and this part works properly.

Hi everybody, I need to use the TRNG unit in FR8003A but I can't find its driver inside the SDK folder. Please help me find it. Thanks.