adafruit gpio

Https://www.raspberrypi.org/documentation/usage/gpio/README.md2016/6/25GPIO: Raspberry Pi A and B# #介绍GPIO和在树莓派上进行物理编程The powerful feature of the Raspberry Pi is the GPIO (general purpose input and output) pins that surround the board, right next to the yellow video output jack.GPIO PinsThese pins are the physical interfaces of the PI and the outside world. The s

1. API interface Request Gpio Port int gpio_request (unsigned gpio, const char *label) free Gpio port void Gpio_free (unsigned gpio)Determine if the GPIO index number is valid (Gpio port exists) int gpio_is_valid (int number);

When writing the key driver, want to know how the kernel manages the GPIO, so began to trace the code, the middle of a few detours, is now recorded here.Before I trace the code, I guess: first, this part of the code should be executed in the system set up stage, and second, the Gpio code should be in machine or platform or vendor related directories. It turns out that the 1th is correct, and the 2nd is fund

Requirement Description: The status light on the Main Board should correctly display the connection status of The ONU module. That is, when the light node module is inserted into the main board slot, the status light should be on and removed. Hardware interface: When SFP module is plugged in, the gpio [2] status will change from high to low automatically.When SW detect the change, just make the gpio [18] t

Gpio: In the output mode of the I/O port, three output speeds (2 MHz, 10 MHz, and 50 MHz) are available ), this speed refers to the response speed of the I/O port drive circuit, rather than the output signal speed, the output signal speed is related to the Program (multiple output driving circuits with different response speeds are arranged in the output part of the chip at the I/O port, you can select a proper driver circuit as needed ). Select diffe

Gpio Gpio, short for general purpose I/O. Its pins can be used for programming. Embedded systems often have a large number of external devices, but the structure is relatively simple. to control these devices, sometimes only one control signal is needed, that is, you only need to turn on/off the two states, such as light and off. Traditional serial port and parallel port are not suitable for controlling the

1, the gpio13 and Gpio17 also as ordinary gpio use, modifytarget/linux/ar71xx/files/arch/mips/ath79/mach-dragino2.c files are as follows/** Dragino V2 Board support, based on Atheros AP121 Board Support * * Copyright (C) 2011-2012 Gabor juhos */#include#include#include#include"Common.h"#include"dev-eth.h"#include"Dev-gpio-buttons.h"#include"dev-leds-gpio.h"#include"dev-m25p80.h"#include"dev-spi-gpio.h" /

Transfer to electronic technology forum: http://bbs.topeetboard.comWhen a GPIO register is converted through the Ioremap function, it is possible to control the physical address (the actual address of the register) by directly controlling the virtual address, thus realizing the Gpio read and write and any other functions.Basic knowledge RequiredVirtual Address and Physical addressMemory Management Unit Conc

/* Gpio Bank summary:** Bank gpios style slpcon extint Group* A 8 4bit Yes 1* B 7 4bit Yes 1* C 8 4bit Yes 2* D 5 4bit Yes 3* E 5 4bit Yes none* F 16 2bit Yes 4 [1]* G 7 4bit Yes 5* H 10 4bit [2] Yes 6* I 16 2bit Yes none* J 12 2bit Yes none* K 16 4bit [2] No none* L 15 4bit [2] No none* M 6 4bit no irq_eint* N 16 2bit no irq_eint* O 16 2bit Yes 7* P 15 2bit Yes 8* Q 9 2bit Yes 9** [1] bankf pins 14,15 do not form part of the external interrupt source

One function analysis (s3c2410_gpio_setpin), analysis of arm gpio address conversion Http://blog.163.com/ruoshui723 Directory:1 S3c2410_gpio_setpin and source code 2 In-depth tracking of some codes in the kernel squadron 3 arm Io memory ing computing and analysis 4 In some trivial cases, 1 s3c2410_gpio_setpin serves as well as the source code. This function sets the gpio data output based on input parameter

Gpio is the most basic input and output channel of the ARM chip. In ads, operations are performed by a single-chip microcomputer and its registers are directly read and written. On the arm9-7 platform, the Windows CE system maps the real IP address of gpio (for example, the base IP address of gpio 2410 is 0x56000000) to the virtual IP address space (the

Next on the analysis, first tracking the source code: ARCH/ARM/mach-mx27/mx27ads_gpio.c Gpio_sensor_active-> gpio_request_mux-> gpio_config_mux Gpio_config_mux is used to complete the configuration of the required pin mode: * @ Brief gpio_config_mux-Just configure the mode of the gpio pin.* @ Param pin a PIN number as defined in/B # iomux_pin_name_t* @ Param mode a module as define in/B # gpio_mux_mode_t;* Gpio_mux_primary set pin to work as primary

0 PrefaceThis paper uses the Freemodbus protocol stack to implement the Modbus TCP slave on the Easyarm i.mx287.The coil registers are defined in the slave. The output of the Gpio can be controlled by the modbus instruction when the 4-bit and easyarm P2.4 to P2.5 are associated with the lower register address of the midline ring. This article changes from Freemodbus Demo sample linuxtcp. Simple changes are also available for other Linux development bo

Linux kernel header file macro about S3C2410 gpio1. gpio register Definition 1. # define gpcon (x) _ reg2 (0x56000000, (x) * 0x10) This statement defines the control register of gpio 2410. Note that the _ reg2 parameter is the physical address of the register. This physical address is converted to a virtual address through the _ reg2 macro, compare the 2410 manual to get the corresponding relationship: Gpco

: Because in most cases the status change of a GPIO triggers the application to perform some actions. In order to facilitate the NRF51 official to encapsulate the process into Gpiote, full name: The GPIO Tasks and Events (gpiote).From Gpio level changes to the process of generating interrupt events1. Gpiote OverviewNRF51 has 32

STM32 Learning is a gradual process, gradually familiar with a peripheral, to understand the register-related configuration, and then on this basis to achieve the function, the road to a step by step, grasp the knowledge of more natural know the direction of the road. Gpio is the most important peripheral of STM32, and almost all peripheral implementations are based on GPIO, so in-depth understanding is nec

General Purpose Input Output (Universal input/output) abbreviated as GPIO, or bus extender, simplifies the expansion of I/O ports with industry standard I²C, SMBus, or SPI interfaces. GPIO products provide additional control and monitoring capabilities when the microcontroller or chipset does not have enough I/O ports or when the system requires remote serial communication or control.This article has nothin

The Linux user layer directly operates GPIOUnder the guidance of an expert, the application layer can operate the GPIO directly, which refers to setting the input and output of the GPIO and the high or low output level. This greatly improves flexibility, the official documentation has GPIO Sysfs Interface for Userspace,gpio