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Sinapse-Energia / MIFARE-US

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[BASICS] To set not used Pins #24

Closed sinapseenergia closed 7 years ago

sinapseenergia commented 7 years ago

Not used Pins have to be set as reccomended by vendor

http://www.st.com/content/ccc/resource/technical/document/application_note/a2/9c/07/d9/2a/b2/47/dc/CD00004479.pdf/files/CD00004479.pdf/jcr:content/translations/en.CD00004479.pdf

Configuration An open (floating) pin is a potential hazard to the circuit. I/O pins which are not used in the application should be preferably configured in output low state . This will also minimize the current consumption.A major source of emission in microcontroller based applications can be due to high speed digital I/O and communication interfaces such as SPI, I2C clocks, USB or PWM. The Rise/Fall times are critical. Typical designs add RC low pass filters.

soporteHW commented 7 years ago

Implemented the following function:

void _GPIOdefault(void)

This function defines and sets unused GPIO as shows:

GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_PULLDOWN;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;

The unused I/O pins are defined in "main.h" file.