ATMEL SPI PROGRAMMER SOFTWARE

The following is the list of hardware and software used in this project: As you understand how the SPI principal works, now its time to implement it with the Atmel AVR ATMega168 microcontroller. By using the highest possible clock allowed such as the Microchip MCP23S17 SPI slave I/O device (10 MHz) than the complete data transfer between the microcontroller and this SPI I/O port could be achieve in 0.8 us. On the first clock cycle both master and slave shift register will shift their registers content one bit to the left the SPI slave will receive the first bit from the master on its LSB register while at he same time the SPI master will receive its first data from slave on its LSB register.Д¬ontinuously using the same principal for each bit, the complete data transfer between master and slave will be done in 8 clock cycle. By activating the CS (chip select) pin on the slave device, now the slave is ready to receive the data.

ATMEL SPI PROGRAMMER SERIAL

Since the SPI protocol uses full duplex synchronous serial data transfer method, it could transfer the data and at the same time receiving the slave data using its internal shift register.ДЇrom the SPI master and slave interconnection diagram above you could see that the SPI peripheral use the shift register to transfer and receive the data, for example the master want to transfer 0b10001101 ( 0x8E) to the slave and at the same time the slave device also want to transfer the 0b00110010 ( 0x32) data to the master.

If more then three SPI slave devices, then it is better to use from three to eight channels decoder chip such as 74HC138 families. If more the one SPI devices is connected to the same bus, then we need four ports and use the fourth port ( SS pin on the ATMega168 microcontroller) to select the target SPI device before starting to communicate with it. The standard Serial Peripheral Interface uses a minimum of three line ports for communicating with a single SPI device (SPI slave), with the chip select pin ( CS) is being always connected to the ground (enable). The principal we learn here could be applied to other types of microcontroller families.

ATMEL SPI PROGRAMMER HOW TO

In this tutorial we will learn how to utilize the Atmel AVR ATMega168 SPI peripheral to expand the ATMega168 I/O ports and to communicate between two microcontrollers with the SPI peripheral where one microcontroller is configured as a master and other as a slave. The last three interface types is used for long connection between the microcontroller and the devices, up to 1200 meters for the RS-485 specification, while the first three is used for short range connection.ДЄmong these serial data transfer interface types, SPI is considered the fastest synchronous with full duplex serial data transfer interface and can be clocked up to 10 MHz that is why it is widely used as the interface method to the high speed demand peripheral such as the Microchip Ethernet controller ENC28J60, Multi Media Card (MMC) Flash Memory, Microchip SPI I/O MCP23S17, Microchip 128K SPI EEPROM 25AA128, ADC, sensors, etc. Currently there are few types of modern embedded system serial data transfer interface widely supported by most of the chipвЂ™s manufactures such as I2C (read as I square C), SPI (Serial Peripheral Interface), 1-Wire (One Wire), Controller Area Network (CAN), USB (Universal Serial Bus) and the RS-232 families (RS-423, RS-422 and RS-485). Because usually we only have a limited I/O port left than the logical choice is to use the serial data transfer method which usually only requires from one up to four ports for doing the data transfer. Sometimes we need to extend or add more I/O ports to our microcontroller based project. Using Serial Peripheral Interface (SPI) Master and Slave with Atmel AVR Microcontroller Jby rwb, under Microcontroller.

Atmel spi programmer