Karen’s Status Report for 12/03

Arden integrated my schedule code into the main code for the nodes, and I’ve made some adjustments since the integration. One of  the changes I made was improving the temperature sensing for fire detection. I used a hairdryer to test how much the ADC measurement changed after being heated up for a few seconds. I used these  tests  to find a good  threshold for how much of a temperature difference over a short period of time should indicate a “fire”. I noticed  that the reading on the ADC consistently dropped a bit from the first reading to the last reading, so I also took some unused measurements before taking the “start” temperature measurement in order to warm up the sensor. I found that there was less change between readings after that. I also took the average of a few measurements to get the “start” and “end” temperatures, just to make  the sensing a bit more consistent. I also added code  to put the nodes in standby once the schedule is done executing. Previously the nodes would just print that they should go into standby, now they actually do it. During testing, when the nodes successfully reached the end of the data phase the nodes would come out of standby within 1 second of each other. This makes sense given that they are using a 1Hz clock to determine when to wake up from standby. Finally, I wrote the code for parsing the graph of the tree and the information gained during the data phase into a json file for the web app. I found a library called json-c, and initially tested it on a fake tree and fake data. In tests with the nodes that reached the end of the data phase, the web app accurately displayed the tree. We have not yet been able to test with the fire detection to see if it accurately displays a node detecting a “fire”, or what happens when a node goes offline.