#I2c clock line arduino uno pinout serial
#I2c clock line arduino uno pinout software

I 2C was originally developed in 1982 by Philips for various Philips chips. The hardware at either end is usually a very simple shift register, allowing easy implementation in software. SPI is good for high data rate full-duplex (simultaneous sending and receiving of data) connections, supporting clock rates upwards of 10MHz (and thus, 10 million bits per second) for some devices, and the speed scales nicely. SPI only allows one controller on the bus, but it does support an arbitrary number of peripherals (subject only to the drive capability of the devices connected to the bus and the number of chip select pins available). Also, the large number of connections for each device can make routing signals more difficult in tight PCB layout situations. The rapid proliferation of pin connections makes it undesirable in situations where lots of devices must be connected to one controller. Connecting a single controller to a single peripheral with an SPI bus requires four lines each additional peripheral device requires one additional chip select I/O pin on the controller. The most obvious drawback of SPI is the number of pins required.

#I2c clock line arduino uno pinout serial

While there is no theoretical limit to asynchronous serial communications, most UART devices only support a certain set of fixed baud rates, and the highest of these is usually around 230400 bits per second. While it is possible to connect multiple devices to a single serial port, bus contention (where two devices attempt to drive the same line at the same time) is always an issue and must be dealt with carefully to prevent damage to the devices in question, usually through external hardware.Р”Р‡inally, data rate is an issue. At least one start and stop bit is a part of each frame of data, meaning that 10 bits of transmission time are required for each 8 bits of data sent, which eats into the data rate.Р”Р„nother core fault in asynchronous serial ports is that they are inherently suited to communications between two, and only two, devices.

#I2c clock line arduino uno pinout software

The two devices must also have clocks that are close to the same rate, and will remain so-excessive differences between clock rates on either end will cause garbled data.Р”Р„synchronous serial ports require hardware overhead-the UART at either end is relatively complex and difficult to accurately implement in software if necessary. Because serial ports are asynchronous (no clock data is transmitted), devices using them must agree ahead of time on a data rate.