i2c bus

the program ......Compared with the 51 program, most of them are the same. Here I will mainly explain the differences between the two.It can only be counted as a platform transplant ....The source program will be appendedReading and Writing SDA and SCLIn fact, the implementation of IIC Bus Protocol is to control the two lines so that data can be transmitted at the specified time.Among them, the most important thing is the write operation on the SCL a

Https://www.cnblogs.com/aaronLinux/p/6896573.html Note: If you set the I2c_slave, the prompt device_busy, you can use the I2c_slave_force, in the driver which corresponds to the same Case statement application layer can call the interface: I2c_smbus_write_ Word_data (FD, __, __); and I2c_smbus_read_word_data (fd,__); Share : https://stackoverflow.com/questions/9974592/i2c-slave-ioctl-purpose The questions are as follows : 1. The direct FD handle in

book. Then look at the data structure of the callback function, specifically what to do is more clear. According to the content of the function, the driver automatically detects the device on the I2C bus when it is loaded, so it automatically discovers the temperature sensor. Lm75_update_device () is a function used for polling readings of temperature sensors. According to the article guideline, look at th

SMBus is a two-wire serial bus. Its first specification was commercially available in 1996. It is mostly based on I2C bus specifications. Like I2C, SMBus does not require additional pins. It is created to add new features, but only works at kHz and is dedicated to smart battery management applications. It works in Mast

Data Bus, address bus, control bus-Linux general technology-Linux technology and application information, the following is a detailed description. It is about the data bus, the address bus, and the control bus. The number of cpu d

During the data transmission of I2C bus, the master controller and the beam controller work in two opposite states and do not change during one communication;1. When the main controller is a transmitter (main control transmitter), the Controller is a receiver (controlled receiver );2. When the main controller is a receiver (the main controller is a dazzling receiver), the Controller is a transmitter (the co

1. Power-on sequence, omitted directly 2. waitclock sends two bytes of 0x00 to the I2C bus. The specific method is to write a byte 0x0 to the address 0. 3. Run the "0xb8 00 00 0x0a" command to directly return the command and data. The rule of at88 is to send commands before reading and writing data each time. Therefore, reading and writing data must contain commands. The Data Writing operation is very

Bh1750fvi is a digital ambient optical sensor IC produced by Rohm semiconductor in Japan. Its main features include: I2C digital interface, supporting a maximum rate of 400 kHz Illuminance) Measurement Range: 1 ~ 65535 Lux, minimum resolution Power down Shielding illumination variation interference caused by 50/60Hz Mains Frequency Two I2C addresses are supported and selected through the ADDR pin. S

I2C is a serial data communication protocol invented by Philips. It only uses two signal lines: serialclock (SCL) and serialdata (SDA ). I2C is a bus structure, with one master, one or more slave. Each slave device is differentiated by a 7-bit address, followed by a read/write bit, indicating read (= 1) or write (= 0), so sometimes we can also see eight-bit devic

groups of resources are defined here, which describe the resources of an I2C device, and 1st describe the BUS address range occupied by this I2C device, ioresource_mem indicates that the 1st group describes the memory-type resource information, the 2nd group describes the interrupt Number of the I2C device, and the io

Driver I2C problems-general Linux technology-Linux technology and application information, the following is a detailed description. I recently learned the i2c device driver. When registering the driver, I need to match the registered device. If the matching succeeds, I will jump to the probe function defined by the driver; Later, I checked that i2c devices put t