CubeMX RTC number format

[StefanRickli]

All input fields in the RTC section for dates and times suggest that I'm entering a decimal value. But the generated code interprets my input as Hex.

I.e. if I enter 10 in the field for the RTC alarm seconds, the code sets "sAlarm.AlarmTime.Seconds = 0x10;"

This confusion arises because the value check of these fields can only be "Decimal" or "No Check". When I check "Hexadecimal", the selection stays at the last selected choice.

STM32CubeIDE 1.8.0

Selected MCU in CubeMX: STM32L422RBIx

[KnarfB]

RTCs traditionally often use BCD (binary coded decimal) format using 4-bit per decimal digit. The most close format C offers natively is hex, also using 4-bit per (hex-)digit. In BCD logic 0x10 is October, 0x31 the last day in March etc... Addition is decimal, e.g. 0x09 + 0x01 = 0x10.

hth

KnarfB

[waclawek.jan]

Cube is open source, so you can easily look up how the RTC functions treat those values.

You may also want to read the documentation, in this case the RTC-related chapters in UM1884.

JW