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vex_robotics_platforms:vex_edr:cpu:cortex:uart_ports

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vex_robotics_platforms:vex_edr:cpu:cortex:uart_ports [2017/05/24 23:11]
pruckelshaus old revision restored (2017/05/23 19:42)
vex_robotics_platforms:vex_edr:cpu:cortex:uart_ports [2017/05/28 02:22] (current)
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-====== ​(UART Ports======+====== UART Ports ======
  
 +A **UART**, or **U**niversal **A**synchronous **R**eceiver and **T**ransmitter,​ is a microcontroller peripheral that sends and receives [[wp>​Serial port|serial]] data at the level of its I/O voltage. The Cortex has two UART ports.
 +
 +==== Applicable Sensors ====
 +  * VEX LCD
 +
 +==== Theory ====
 +
 +{{:​vex_robotics_platforms:​vex_edr:​cpu:​cortex:​uart_serial_port.jpg?​400|}}\\
 +RS-232 ports on a computer use the same protocol as a **UART** with only voltage differences
 +
 +Logic-level serial protocols usually use a high voltage as a "​space"​ signal and a low voltage as a "​mark"​ signal (known as //​non-inverted mode//). If a protocol uses the opposite, it is known as //inverted mode//.
 +
 +Serial communication proceeds in much the same way as in a standard RS-232 port. The most common settings are 8 data bits, no [[wp>​parity bit]], and one stop bit, with no [[wp>​flow control]]. Available [[wp>​baud]] rates tend to remain the same as conventional serial ports, but can go much faster, as much as 2 Mbaud for some microcontrollers.
 +
 +==== Applications ====
 +
 +UARTs are cheap to implement and easy to use; most advanced microcontrollers such as the LeafLabs Maple and Netduino come with more than one (the Cortex comes with two). Serial communication through a UART is usually the easiest way to pass debugging messages to a PC. Many microcontrollers also accept programming downloads through a UART connection. Almost every microcontroller supports at least one UART, making it a quick and universal way to communicate. However, UARTs are very slow and vulnerable to noise compared to protocols such as SPI.
 +
 +Due to the lack of RS-232 ports on modern computers (which can be connected to a UART using only a voltage level translator),​ most computers must use a USB to UART converter such as ((http://​www.sparkfun.com/​products/​9716)) to connect to a logic-level UART on a microcontroller.
vex_robotics_platforms/vex_edr/cpu/cortex/uart_ports.txt · Last modified: 2017/05/28 02:22 (external edit)