raspi gpio

Before learning I2C Drive, think about it should be a profound understanding of the I2C agreement. Personally feel that the best way to understand the I2C protocol is to practice, and the best practice is to use GPIO to simulate the I2C protocol test, intuitive and profound.First look at the I2C sequence diagram:According to the sequence diagram, the SDA and SCL can be simulated with two gpio respectively.

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

Today, I am familiar with some gpio applications. The simplest is the control of LED lights. The following example uses L5 to describe it. Sysctlperipheralenable (sysctl_periph_gpiob); // enable gpio B Gpiopintypegpiooutput (gpio_portb_base, gpio_pin_0); // set pb0 output Another mode setting method is gpiodirmodeset (gpio_portb_base, gpio_pin_0, gpio_dir_mode_out). // multiple pins can be set in this mode.

Someone in the Forum said they wanted to get a car with the infrared control gpio and asked me how to get it. I wrote this post.I soldered four LEDs on the gpio port, representing the upper, lower, and lower layers.You can not only control gpio, but also execute any shell.It's not lirc, It's a lightweight infrared receiver I wrote.CBOs GM hasRunning method (Pleas

This section describes the simplest and most basic things. The ios operation of the cc2540 uses the Port port as the gpio. If you don't talk much about it, let's look at it. 1. Hardware Circuit The most simple hardware circuit is to use a gpio to control the LED light. Since gpio is used as the output, the gpio mode is

　　The GPIO pin has two modes board and BCM.1.GPIO output Control LED：　　Code:　　　　(1) Using board mode, GPIO.setmode(GPIO.BOARD) . Pin 35th is GPIO19 under BCM.(2) Set pin 35 to output mode,GPIO.setup(35,GPIO.OUT)(3) on the GPIO35 pin output high level, can also be Gpio.high2.GPIO interface for input signal：　　Circuit diagram　　When the switch is off, the GPIO23 is t

Although the em3 of efm32 has a low power consumption of 0.6ua, it is still a waste in some occasions. In particular, the one-time consumption of battery power supply products, the customer's idea is that the lower the better, it is better not to consume power. Therefore, in many cases, the MCU can only enter the em4 status. When efm32 enters the em4 status, almost all modules in the chip are powered off. Only a few special gpio ports and external r

Each gpio port has two 32-bit configuration registers (Gpiox_crl, gpiox_crh)Control the High and Low eight bits of each port respectivelyIf the IO port is 0-7, write the CRL register. If the IO port is 8-15, write the CRH register, two 32-bit data registers (Gpiox_idr, gpiox_odr)One is the read-only input data register, and the other is the write-only output register., A 32-bit/Reset register (Gpiox_bsrr), A 16-bit reset register (Gpiox_brr) And a 32-

First aid! For details about how to compile the makefile of the gpio driver-Linux general technology-Linux technology and application information, see the following. I need to use the GPIO interface to control the stepper motor. The gpio driver code adds the pin control I need according to the \ drivers \ char \ EmbedSky_gpio.c code under the source code of the k

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

according to Datasheet Documentation described, when when the Jtag_gpio_mode register is set to 1 , theJTAG pin function is gpio, and the corresponding Gpio sequence number is gpio17~gpio21. Setting the JTAG interface to GPIO requires modifying the jtag_gpio_mode of the Gpiomode register Bits,thegpiomode Register is located in the SYSCTL Register Group, as descr

For CC2530 Gpio Basics, General Gpio operation about registers, IAR Embedded Workbench IDE software use: TI CC2530 Basic Experiment (ordinary GPIO operation-Light LED)Schematic diagram of the circuit:Analysis : You need to press the button to light the light, and do not use the interrupt mode, that is, we need to monitor whether the press is pressed (P0_4 is low,

1.GPIO IntroductionGPIO (General purpose I/O ports) means universal input/output port, which is popularly said to be some pins.We can use them to output high or low levels or the state of the read-in PIN.There are 130 I/O ports in the s3c2440, divided into 9 groups A~j, GPA, GPB 、..... GPJ2.GPIO RegistersSince the gpio is to be manipulated, the corresponding regi

That said, if the Convention are supported on their platform, drivers shouldUse it when possible. Platforms must declare GENERIC_GPIO support in theirKconfig (Boolean True), and provide an Work without standard GPIO calls should has Kconfig entries which dependOn Generic_gpio. The GPIO calls is available, either as "real code" or asOptimized-away stubs, when drivers use the Include file:#include Identifying