Monthly Archives: November 2015

STM32F411 RC Calibration Using a DS3231 TCXO 1HZ Signal

Posted on November 20, 2015 by

STM32 RC oscillator frequency varies from one chip to another due to manufacturing process variations. ST claim each device is factory calibrated for 1% accuracy at 25°C. Thus, after reset this factory calibration value is loaded in the HSICAL[7:0] bits … Continue reading →

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STM32F411 Nucleo I2C DS3231 1Hz Square Wave with External Interrupt

Posted on November 10, 2015 by

Bare metal like. A very basic demonstration of STM32 I2C communications with a DS3231 chip (in the form of a ChronoDot). The program uses I2C to communicate with the DS3231 chip. It sets the DS3231 date and time, and commands … Continue reading →

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