I2C ProtocolTwo-line serial protocol (SCL, SDA), master-slave mode, support multiple master, but at the same time only one Master address composition: 7bit address array +1bit read-write bit, a total of 8bit. Address range 0~127, 0 address is broadcast address. Send 8bit data at a time, the data format is big-endian mode. Rate: Standard mode 100Kbps, fast mode 400Kbps, high speed mode 3.4Mbps.
Bus Interconnect
Note that both the SDA and the SCL requi
About I2C, this is also the previously tangled part. Note.
(For details, refer to: source; Phodal'sBlog)
The I2C (Inter-Integrated Circuit) bus is a two-line serial bus developed by PHILIPS to connect the microcontroller and its peripheral devices. It is a bus standard widely used in the field of microelectronics communication control. > The I2C bus supports any
that I could. But the expansion of G is really a little slow. It takes about 10g a minute. But fortunately, I finally finished it, and made a sweat.
In the afternoon, I checked the setting of Interrupt registers on 8607. Use three interrupt registers, 0x [3-5], and each bit uses a mask to set an interrupt. Every one is 8 bits. There are also 24 interruptions. This is read and write using I2C. I was a bit confused when I was writing registers. When I
# Modify the configuration file
Raspberry Pi has integrated the I2C driver and only needs to be started.
Modify configuration file
Sudo nano/etc/modprobe. d/raspi-blacklist.conf
! [Configure] (http://images.cnblogs.com/cnblogs_com/hangxin1940/466697/o_rasp_i2c1.png "comment the third line ")Comment out the third line, CTRL + x save
Next, start the I2C module.
Sudo nano/etc/modules
! [Configure] (ht
According to their own understanding, the http://lxr.linux.no/linux+v2.6.34/Documentation/i2c/instantiating-devices is translated into the document about enumerating and establishing i2c_client. Have objections or questions please refer to the original, after all, the core of the document is the true essence.
Method 1: Use the bus number to declare the device. defines the device's information in the initialization of the kernel. The prerequisite is
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 simple. The first byte of the command is use
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 device addresses. At this time, each device has tw
AbstractFm31256 is a multi-functional storage chip based on I2C bus and powered by the iron and electronics technology. In addition to non-volatile memory, the device also provides real-time clock, low-voltage reset, watchdog counters, non-volatile event counters, lockable serial digital identification, and other features. This article mainly introduces the basic functions and principles of fm31256, and gives the specific application methods of fm3125
I2C has never been touched before, so its simulation function can only rely on the feeling, there is something wrong, still hope that the House correct. With the SPI-related simulation function, it is not difficult to do I2C, but it is a little troublesome for users to read and write data through the I2C bus.Test program running interface: the
========================================================== ====Author: yuanlulu
Http://blog.csdn.net/yuanlulu
No copyright, but please keep this statement for reprinting========================================================== ====
For more information about how to create i2c_client, see http://blog.csdn.net/yuanlulu/archive/2011/06/21/6557901.aspx.
2.6.34 I2C sub-systems no longer distinguish between legacy model and standard drivermodel drivers.
An in-depth understanding of I2C bus clock synchronization and bus arbitration
Each IIC bus device has the same circuit structure of the SDA and SCL pins, and the output drive of the pins is connected with the input buffer. The output is a field effect tube with an open drain path, and the input buffer is a high-input impedance phase generator [1]. This type of circuit has two features:
① Because SDA and SCL are Drain open circuit structures, the "lin
How to enable I2C device http://www.cnblogs.com/hangxin1940/archive/2013/04/02/2997077.html and build a python I2C Development Environment http://www.cnblogs.com/hangxin1940/archive/2013/04/03/2997094.html
Quick2wire is a python library used for I2C communication on Raspberry Pi. It allows non-root users to read and write gpio pins conveniently.
Why use it?
Some
The last 2 weeks have been debugging IIC and SPI bus equipment, here record 2 kinds of bus, in case of forgetting.
One IIC Bus
The abbreviation of I2c--inter-ic serial Bus is the serial transmission bus between chips introduced by Philips company. It implements duplex synchronous data transfer with 1 serial data cables (SDA) and 1 serial clock lines (SCL). The utility model has the advantages of less interface line, simpler control mode, smaller devic
Linux under a lot of devices are used to the I2C, so look at the driver of the I2C, although now understanding may still be human and material resources, but at least there are some basic concepts
Reference:
http://blog.csdn.net/ylyuanlu/article/details/6705942
http://blog.csdn.net/hongjiujing/article/details/4098547
Look at the I2C initialization process:
[CP
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
Demand:Read the value of the embedded temperature sensor.
Known conditions:* The temperature sensor has been welded on the motherboard.* Temperature Sensor Model LM75*linux Drive, in linux-2.6.20.21/drivers/hwmon/lm75.c* The circuit of the temperature sensor
Questions and Answers:*linux How to use the drive with its own.
Look at the LM75.C code and find out that this temperature sensor is using a I2C bus.The code sees the
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
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