130 likes | 274 Views
ECET 581. Wireless Sensor Networks Mote – MCU & Sensor Hardware 2 of 3 Fall 2006 http://www.etcs.ipfw.edu/~lin. WSN Mote & Sensor Hardware. Timer DMA – Direct Memory Access JTAG USART/USCI SPI – Serial Peripheral Interface I2C RF Transceiver. Timers on the MSP430. Timer_A3
E N D
ECET 581 Wireless Sensor Networks Mote – MCU & Sensor Hardware 2 of 3 Fall 2006 http://www.etcs.ipfw.edu/~lin WSN Mote- MCU & Sensor Hardware
WSN Mote & Sensor Hardware • Timer • DMA – Direct Memory Access • JTAG • USART/USCI • SPI – Serial Peripheral Interface • I2C • RF Transceiver WSN Mote- MCU & Sensor Hardware
Timers on the MSP430 • Timer_A3 • 16-bit timer/counter with 3 capture/compare registers • PWM output • Interval timing • Interrupts • Timer_B3 • Watch Dog Timer WSN Mote- MCU & Sensor Hardware
DMA • DMA – Direct Memory Access • Move a block of data in memory from system RAM to/from a buffer without using the CPU • CPU bus access turned over to DMA controller • Applications • Network packet routing • Audio playback • Streaming video WSN Mote- MCU & Sensor Hardware
DMA • 3-independent channels for DMA transfer • DMACTL0- (DMA Control Register 0) - DMAxTSELx bits: triggering & data transfer • DMACTL1 (DMA Control Register 1) • Handle conflicts for simultaneous triggers • Priorities • DMAxCTL - DMA Channel Control Register • Single Transfer • Block Transfer – entire data block • Burst-Block Transfer – allow interleave CPU and DMA • Repeated Single Transfer • Repeated Block Transfer • Repeated Burst-Block Transfer WSN Mote- MCU & Sensor Hardware
MSP430 - JTAG • JTAG (Joint Test Action Group) Flexible Printed Circuit Interface • IEEE 1149.1 Standard Test Access Port and Boundary-Scan Architecture - 1990 • MSP430 on-chip JTAG interface • 2-wire JTAG (Spy-Bi-Wire or SBW) • 4-wire JTAG (standard) • TMS – In, signal to control the JTAG state machine • TCK – In, JTAG clock input • TDI – In, JTAG data input/TCLK input • TDO – Out, JTAG data output • JTAG In Circuit Debugger & Programmer • TI MSP-FET430UIF connected to a USB port • TI MSP-FETP430 JTAG interface connected to the PC’s parallel port WSN Mote- MCU & Sensor Hardware
MSP430 - JTAG • Programming Flash-based MSP430 using the JTAG interface • High-level Macros • IR_SHIFT (8-bit instruction) • Shifts an 8-bit JTAG instruction into the JTAG instruction register • DR_SHIFT16 (16-bit data) • Shifts a 16-bit data into the JTAG data register • DR_SHIFT20 (20-bit address) • Shifts a 20-bit address into the JTAG memory address bus register • MsDelay (time) – wait a specified ms • SetTCLK – set TCLK to 1 • clrTCLK – set TCLK to 0 • TDOvalue – variable containing the last value shifted out on TDO WSN Mote- MCU & Sensor Hardware
USART/USCI • USART – Universal Synchronous/Asynchronous Receive Transmit using double-buffered transmit/receive channels • A clock – shared by sender and receiver • Asynchronous – full duplex • Synchronous – master, half duplex • Synchronous – Slave, half duplex • USART supports • synchronous SPI (3 or 4 pin) • Asynchronous UART • I2C (standard mode 100kbps, fast mode 400 kbps) WSN Mote- MCU & Sensor Hardware
SPI – Serial Peripheral Interface • Synchronous serial communication of host processor and peripherals • SPI Interface • Based on a 8-bit shift register • SCK (serial shift clock) provided by the master device. • SCK a gated clock • Only generated during shifting • SCK stays idle between transfer • 3-wire • Serial clock (SCK) • SDI – Data In • SDO – Data Out WSN Mote- MCU & Sensor Hardware
I2C Bus • A serial computer bus, Inter-Integrated Circuit (I2C), invented by Philips for low-speed peripherals communications • 2-wire bi-directional serial bus • SCL - Clock Line • SDA – Data Line • Introduced by Philips 20 years ago • Three data transfer speeds • Standard mode - 100 kbps • Fast mode - 400 kbps • High speed mode - up to 3.4 Mbps • Master and Slave WSN Mote- MCU & Sensor Hardware
CC2420 RF Transceiver • 2.4 GHz IEEE 802.15.4/ZigBee-ready RF Transceiver • 2400-2483.5 MHz RF • Low-power and low-voltage wireless applications • DSSS (Digital direct sequence spread spectrum) based modem • Spreading gain of 9dB • Effective data rate of 250 kbps • Separate transmit and receive FIFOs: 128 byte each • 4-wire SPI interface, serial clock up to 10 MHz WSN Mote- MCU & Sensor Hardware
CC2420 RF Transceiver • Testing CC2420 WSN Mote- MCU & Sensor Hardware
CC2420 RF Transceiver • CC2400EB WSN Mote- MCU & Sensor Hardware