4. LPRF in Practice

1. 4. LPRF in Practice Thomas Watteyne @ EDERC 2010

2. Hardware - Overview sensors micro-controller radio battery mote Thomas Watteyne @ EDERC 2010

3. Hardware - Criteria • Radio-chip • Low-power • Standards compliant? • Community / Support • Micro-controller • Reasonably fast • Low-power • Multiple I/O options • Reasonable amount of memory • Timing capabilities • Community / support Thomas Watteyne @ EDERC 2010

4. Hardware - Microcontrollers a used as cache, primary memory is off-chip b at 1MHz c at 8MHz Thomas Watteyne @ EDERC 2010

5. Hardware - Radios a at 0dBm transmission power b at 3dBm transmission power Thomas Watteyne @ EDERC 2010

6. Hardware - Motes Thomas Watteyne @ EDERC 2010

7. Software - Options Thomas Watteyne @ EDERC 2010

8. Development Tools • Firmware development is complex • not complicated! • developtop-down, always keep an eye on where you’re going • the vast majority of the cases, you’re wrong (not the compiler, not the protocols) • bugs are always due to simple errors • build from atomic building blocks • Multi-dimensional Debugging • choose a meaning for each LED, and stick with it • print out error codes, not text • Use the extension pins with an oscilloscope, the easiest way to measure time • Use a spectrum analyzer to see on what channels you are occupying • Use a sniffer to see the packets flying through the air • A GUI is faster than lines text • Use a JTAG debugger whenever possible Thomas Watteyne @ EDERC 2010

9. Development Tools • Choosing a scope • analog channels for energy (put resistor in series with power source) • the more digital channels, the better • you don’t need a fast scope • some oscilloscopes will interpret SPI, I2C, UART (e.g. Tektronic MSO2024) • cheap USB scopes available • Spectrum analyzers • are expensive • can be replaced by a sniffer • can be replaced by the poor man’s spectrum analyzer • Sniffer • CC2531 EMK ($49) • Graphical User Interface • Python+PySerial is a good candidate Thomas Watteyne @ EDERC 2010