tailieunhanh - NIGEL PIC Tutorial Hardware phần 10

giá trị bằng văn bản là "Địa chỉ Slave" cho chip. Mỗi con chip trên xe buýt phải có một địa chỉ duy nhất hoặc các vấn đề sẽ xảy ra. Mặc dù nó được dán nhãn là kết nối với PORTB, như với hầu hết các Ban, nó cũng có thể được kết nối để Porta nếu có yêu cầu. | value written as the Slave Address for the chip. Each chip on the bus must have a unique address or problems are going to occur. Although it s labelled as connecting to PortB as with most of the boards it can also be connected to PortA if required. This is the top view of the I2C EEPROM Board it has 7 wire links. The bottom of the I2C EEPROM Board there are 7 track cuts please note that there are only 3 between the I C pins one isn t cut as it s used to ground the WP pin. These tutorials require the Main Board the LCD Board and various of the I2C Boards as written the tutorials use the LCD Board on PortA and the I2C Boards on PortB - although these could easily be swapped over as the I2C Boards don t use either of the two difficult pins for PortA pins 4 and 5 as outputs. Download zipped tutorial files. As with the LCD Tutorial the idea is to implement a reusable set of I2C routines. Rather than showing the routines on the page as with earlier tutorials they are getting quite lengthy now I m only going to store them in the pages download ZIP file so you will need to download them. As the I2C tutorials use a number of different boards each section is headed by the I2C boards required in bold type. I2C is a protocol designed by Philips Semiconductors and is for communications between I C s over a two wire synchronous serial bus devices are classed as either Master or Slave for our purposes the Main Board processor is the Master and any other devices are Slaves . The initial tutorials use a 24C04 a 512 byte EEPROM memory chip commonly used for storing the settings in modern TV s and VCR s where they are used to store all the customer settings tuning volume brightness etc. and the internal calibration values for the set which are normally accessed through a special service mode . These chips provide non-volatile memory as a series of 256 byte pages so the 24C04 provides two pages giving 512 bytes of memory. The 24C02 uses standard addressing which gives the 256 byte .