pinLow

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Description

Set the output state of an I/O pin to low (=0V=GND).

If the pin has been configured as an OUTPUT via pinMode() or portMode(), this command drives the pin voltage to low.

Notes:

• after reset all I/O pins are configured as INPUT
• if a pin is configured as INPUT*, pinLow() has no effect.

Inclusion

• defined in gpio.h
• auto-loaded in main_general.h
• no #define required

Syntax

pinLow(pPort, pin)

Parameters

• input:

  • pPort: address of port to set, e.g. &PORT_A
  • pin: pin you wish to set (0..7)

• output:

  • none

Returns

• Nothing

Example Code

The below code makes pin PD0 (=LED on STM8S Discovery) an OUTPUT and toggles it HIGH and LOW with 1s delay.

#include "main_general.h"   // board-independent main

void setup()
{
  pinMode(&PORT_D, 0, OUTPUT);    // set PD0 as output
}

void loop()
{
  pinHigh(&PORT_D, 0);            // set PD0 on
  delay(1000);                    // wait 1s
  pinLow(&PORT_D, 0);             // set PD0 off
  delay(1000);                    // wait 1s
}

Relevant Tutorial

• General_Examples/Minimal-C

Notes and Warnings

To avoid damage

• do not expose I/Os to voltages outside [-0.3V; Vdd+0.3V], else limit injection currents to the specificied limits
• for OUTPUT pins assert that sink and source currents are below the specificied limits
• do not directly connect two OUTPUT pins. If e.g. half-duplex is required, use a pull-up and OUTPUT_OPENDRAIN, instead

See also

• pinMode()
• portMode()
• pinHigh()
• pinToggle()
• pinSet()
• pinRead()
• pinOutputReg()
• pinInputReg()
• portOutputReg()
• portInputReg()
• configEdgeExint()
• configEdgeTLI()