The previous article describes the communication between the Android phone and the BLE terminal, while the most common ble terminal should be the ibeacon base station advocated by Apple. Ibeacon technology based on BLE, it is characterized by the broadcast of external messages, mobile phones do not need to connect to the Ibeacon base station can also obtain its i
A cssp specification-visual enhancement engine chip produced by quick logic is used to enhance the image data output to the Panel. Schematic:
Generally, you only need to add an I2C device and write it to the register group during initialization. Linux I2C architecture:I2C core i2c-core.c: Provides I2C bus drivers and
I2C bus signal timing Summary
Idle bus statusThe SDA and SCL signal lines of the I2C bus are in the idle state at the same time.At this time, the output-level FET of each device is in the cutoff state, that is, the bus is released.By the two signal lines of the respective pull-up resistance to raise the level.
Start SignalThe SDA level of the data line is lowered (that is, the negative hop) during the hig
EmbeddedLinux Bare Metal Development (13)--i²c communication a,IIC Protocol 1. Introduction ofIIC bus i2c (Inter - integrated circuit) bus is a philips The company developed a two-wire serial bus for connecting microcontrollers and peripherals. i2c Bus is a serial data bus, only two signal lines, one is two-way cable sda and the other one is the clock line scl
I'm confused about the I2C bus protocol? I was not quite clear when I first saw it. Let's take a look at the role of the I2C bus. Maybe this will give you a little bit of understanding.
I2C bus application
At present, many semiconductor integrated circuits have integrated I2C interfaces. Single-Chip Microcomputer with
Recently, with the popularity of smart wearable equipment, intelligent medical care and intelligent home, Bluetooth development is very important in moving. Because of the company's needs, we studied the Bluetooth 4.0 application in Android.
Here are some of my summaries.
1. Let me introduce some of the nouns in Bluetooth 4.0:(1), GATT (gneric attibute profile)
Through BLE connection, reads and writes the attribute class small Data Profile general
Address: http://blog.csdn.net/coder_jack/article/details/6419903
Send a start and stop command consecutively for the following test:
1. Send the start command to address an existing device, receive the ACK, and then send the Stop command. Everything is normal and the Stop waveform is displayed.
2. Send the start command to address a non-existing slave device. If no response is received, send the Stop command to release the bus and the waveform of the bus release cannot be seen. Only the check re
Principles, differences and Applications of SPI, I2C, and UART Serial Bus
1. UART is a two-line interface. One transmission and one receiving interface can communicate with each other in full duplex mode, and the number of lines is relatively small. Data is transmitted asynchronously, with strict timing requirements on both parties, and the communication speed is not fast. It is used most frequently for multi-host communication.2. Compared
During Android development and transplantation, you sometimes need to read and write a device, but the system may not provide the corresponding services. We need to develop our own hardware access service to control devices. The following example is the process of reading and writing the most simple I2C device EEPROM, I2C driver writing there are two ways, one is to use the
1.OV PWDN is a high level of effective, that is, high electricity peacetime camera sleep, at this time I2C also do not work (with i2cdetect detection), in low electricity peacetime camera work;
2.i2cdetect is a very good tool, you use this work, do not care about the device's register address and data bit width, as long as the device to ensure the operating voltage and its mount to which a I2C controller, y
Requirements: BLE connection and communication (do now-device on-search device-connect device)Resources: Some demos and official documents from the Web:1-ble is a Android4.3 version of the api-to provide some conceptual things or it is necessary to understandAt present, the Android real machine can only accept and control products-that is, the client side of the-server end is only a product-and Apple seems
A few days ago, something happened. When I went to work in the morning, I took the key of my daughter-in-law and we couldn't lock the door without the key. So when my daughter-in-law was about to leave, she couldn't lock the door, so she had to call me. At that time, I had already arrived at Huo camp. Well, I had to go back and give my daughter-in-law the key. Then I was late for work both of them, I am also very depressed. This is a hot day!
I have been learning
BrieflyThe aerial package format of the link layer should be the basic unit of all packages based on the other layers on the ble Link layer, so it is necessary to have an understanding of the rest of the package, and to analyze the basics of the Bluetooth protocol through the aerial package.Aerial package formatFirst Look at:This is the Bluetooth BLE air packet in the overall format.Preambleheader, used to
This article describes how to implement Ble Bluetooth, a small program. The source code download is provided, which has good reference value. Next let's take a look at the small Editor. This article mainly introduces the implementation of Ble Bluetooth, a small program. The source code download is provided, which has good reference value. Let's take a look at it with the small editor.
Not for a while. I ha
Linux I2C driver architecture1. Linux I2C driver architecture in Linux, I2C BUS drivers are divided into two parts: BUS and DEVICE drivers ). The role of the bus driver is to add corresponding read/write methods for each I2C bus in the system. However, the bus driver does not communicate with each other. It only exists
The I2C architecture consists of three components:
(1) I2C Core
(2) I2C bus driver
(3) I2C Device Driver
I2C core: Provides the registration and cancellation methods for I2C bus drivers and device drivers, the upper layer of the
1. Get the source code of I2C tools
Reference: http://lm-sensors.org/wiki/I2CTools
$ Wget http://dl.lm-sensors.org/i2c-tools/releases/i2c-tools-3.1.0.tar.bz2
2. Compile the source code
$ Tar-jxvf i2c-tools-3.1.0.tar.bz2
$ I2c-tools-3.1.0 CD
$ Cc = arm-None-Linux-gnueabi-GCC
1. Communication Interface
The data sent or received by I2C is encapsulated by the packet struct i2c_msg.
Struct i2c_msg {_ 2010addr; // slave address _ 2010flags; // flag # define i2c_m_ten 0x0010 // ten address flag # define i2c_m_rd 0x0001 // receives the data flag _ Len; // Data Length _ u8 * Buf; // Data Pointer };
ADDR indicates the slave address, flags indicates the communication, 0 indicates the sent data, and i2c_m_rd indicates the received d
ack and nack of I2C signal
We usually in debugging I2C may rarely pay attention to the nack signal, only know if the master send data, MSB first, LSB after sending a byte (8 bit), then Slave will reply to an ACK signal, but sometimes I2C Slave may send a nack signal, let's take a look at the nack signal.
1, from the spec under a paragraph:
2. Translation:
E
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