11 - Embedded Networking and Communications

En esta semana aprenderemos a comunicar diferentes sistemas embebidos con el objetivo de intercambiar información entre sí de una manera segura y optima, conociendo los protocolos de comunicación más utilizados en sistemas embebidos asi como sus ventajas y desventajas.

introducción

Los protocolos de comunicación son reglas que permiten el intercambio de información entre dispositivos conectados a una red. Su objetivo es que los dispositivos puedan comunicarse entre sí de manera eficiente, segura y confiable. A continuación se muestran algunos de los prootocolos de comunicación más populares en sistemas embebidos.

I2C

La comunicación I2C solo usa dos cables para transmitir información entre dispositivos


  • SDA (Serial Data) - The line for the master and secondary to send and receive data.
  • SCL (Serial Clock) - The line that carries the clock signal.
I2C is a serial communication protocol, so data is transferred bit by bit along a single wire (the SDA line). I2C is synchronous, so the output of bits is synchronized to the sampling of bits by a clock signal shared between the master and the secondary. The clock signal is always controlled by the master.

With I2C, data is transferred in messages. Messages are broken up into frames of data. Each message has an address frame that contains the binary address of the slave, and one or more data frames that contain the data being transmitted. The message also includes start and stop conditions, read/write bits, and ACK/NACK bits between each data frame:

  • Start Condition: The SDA line switches from a high voltage level to a low voltage level before the SCL line switches from high to low.
  • Stop Condition: The SDA line switches from a low voltage level to a high voltage level after the SCL line switches from low to high.
  • Address Frame: A 7 or 10 bit sequence unique to each slave that identifies the slave when the master wants to talk to it.
  • Read/Write Bit: A single bit specifying whether the master is sending data to the slave (low voltage level) or requesting data from it (high voltage level).
  • ACK/NACK Bit: Each frame in a message is followed by an acknowledge/no-acknowledge bit. If an address frame or data frame was successfully received, an ACK bit is returned to the sender from the receiving device.
Mas información en el siguiente link.

SPI

Protocol Characteristics Advantages Disadvantages
I2C
  • Two lines: SDA and SCL
  • Up to 127 slave devices
  • Speeds: 100 kbps, 400 kbps, 1 Mbps
  • Only requires two wires
  • Supports multiple masters and secondary
  • Data reception confirmation (ACK/NACK)
  • Slower speed compared to SPI
  • Frame size limited to 8 bits
  • More complex hardware than SPI
SPI
  • Four lines: MOSI, MISO, SCLK, SS
  • Synchronous and full-duplex communication
  • High transfer speed (up to 10 Mbps)
  • Flexibility in data size
  • Simple hardware interface
  • Requires more pins than I2C
  • Does not support hot-swapping
  • Only supports one master device
UART
  • Asynchronous communication
  • Two lines: TX and RX
  • Speeds: 110 bps to 230.4 kbps
  • Full-duplex communication
  • Does not require external clock
  • Error checking with parity bit
  • Does not support multi-slave or multi-master configuration
  • Packet size limited to 9 bits
  • Not suitable for high-speed communication



Resultado final




Learning outcome

En esta semana aprendimos sobre el uso del router y la importancia de una buena planeación, no solo un buen diseño es importante, si no que se debe tener encuenta el recorrido de la maquina, si la madera se encuentra pandeada, el largo de la herramienta de corte, etc.

Group Task


Files