Lab 5 System Design

1. Lab 5System Design Thomas Watteyne EE290Q – Spring 2010 http://wsn.eecs.berkeley.edu/290Q

2. Result

3. Topology origin X sends packet every 1+U(2) seconds Y displays raw bytes in hex format displays GUI gateway sniffer node

4. Packet Structure choose 0x01 measure by hand(unit: feet) 0x01 ADC

5. Medium Access Pure Aloha • Wait for 1+U(2) seconds • Send a packet • Listening not required

6. SubProjects • Send an empty packet with the right format • Measure the battery’s voltage • Measure the temperature • Obtaining a random number • Program a sniffer (with text based output) • Program a gateway (binary output) • Program the GUI

7. 1. Send Empty Packet with the right format • Create project lab5_nodewith C file called system_node • Define global variables MYADDR, MYX, MYY at the beginning of the file • In main(): • Initialize the board • Initialize the radio • Initialize a timer which fires regularly (e.g. every 2s) • When timer fires • Fill all the fields except temperature and battery • Transmit the packet • LEDs: • red: I send • (green: I receive)

8. 2. Measure the battery’s voltage • Create a simple project which reads the voltage when you press a button. You can use the debug mode of IAR to freeze the MSP and read the value • The following functions returns the battery voltage, make sure you understand every line! uint8_t get_battery() { int battery=0; ADC10CTL1 = INCH_11; // AVcc/2 ADC10CTL0 = SREF_1 + ADC10SHT_2 + REFON + ADC10ON + ADC10IE + REF2_5V; for( battery = 240; battery > 0; battery-- ); // delay to allow reference to settle ADC10CTL0 |= ENC + ADC10SC; // Sampling and conversion start __bis_SR_register(CPUOFF + GIE); // LPM0 with interrupts enabled battery = ADC10MEM; ADC10CTL0 &= ~ENC; ADC10CTL0 &= ~(REFON + ADC10ON); // turn off A/D to save power battery = (battery*25)/512; uint8_t batterybyte = battery&0xFF; return batterybyte; }

9. 3. Measure the temperature • Create a simple project which reads the temperature when you press a button. You can use the debug mode of IAR to freeze the MSP and read the value • The following functions returns the temperature, make sure you understand every line! uint8_t get_temperature() { intdegC; volatile long temp; ADC10CTL1 = INCH_10 + ADC10DIV_4; // Temp Sensor ADC10CLK/5 ADC10CTL0 = SREF_1 + ADC10SHT_3 + REFON + ADC10ON + ADC10IE + ADC10SR; for( degC = 240; degC > 0; degC-- ); // delay to allow reference to settle ADC10CTL0 |= ENC + ADC10SC; // Sampling and conversion start __bis_SR_register(CPUOFF + GIE); // LPM0 with interrupts enabled degC = ADC10MEM; ADC10CTL0 &= ~ENC; // oC = ((A10/1024)*1500mV)-986mV)*1/3.55mV = A10*423/1024 - 278 // the temperature is transmitted as an integer where 32.1 = 321 // hence 4230 instead of 423 temp = degC; degC = (((temp - 673) * 4230) / 1024); if( tempOffset != 0xFFFF ) { degC += tempOffset; } return (uint8_t)(degC&0xFF); }

10. 4. Obtain a random number • Create a simple project which blinks the LED with a period of 1+U(2) seconds. • The key function is MRFI_RandomByte(), explore in the drivers how it is implemented • Use the scope to measure the timing; evaluate how uniform the distribution isreads the temperature when you press a button. You can use the debug mode of IAR to freeze the MSP and read the value

11. 5. Program a sniffer • Create project lab5_sniffer with C file called system_sniffer.c • In main() • Initialize the board • Initialize the radio • Enable serial communication • When you receive a packet, output every byte to the serial port using the following format: “<byte>:<value>\r\n” • Check the content of the packets using PuTTY

12. 6. Program a gateway • Create project lab5_gateway with C file called system_gateway.c • In main() • Initialize the board • Initialize the radio • Enable serial communication • When you receive a packet, • In text mode, output every byte to the serial port using the following format:"from XXX @(XXX,XXX) to XXX: T=XX.XC B=X.XV\r\n“ • In binary mode, output a string of uint8_t values using the following format: output[0] = src;output[1] = dest;output[2] = x_coord;output[3] = y_coord;output[4] = type;output[5] = temperature;output[6] = battery; • Pushing the button should switch the output mode

13. 7. GUI • Create a Python GUI called system.py which opens the serial port and receives lines from the mote in the format:output[0] = src;output[1] = dest;output[2] = x_coord;output[3] = y_coord;output[4] = type;output[5] = temperature;output[6] = battery; • Followed by \r\n • Display the motes in space, using x and y, and display the temperature and battery voltage