FTDI provides a software utility, FT_Prog, which allows you to program the ID strings and other aspects of the FTDI chip and associated flash memory. Our in house motes will identify as:
GKxxxxxx /dev/ttyUSB0 Grok Lab TelosB Mote
where xxxxxx is a unique identifier.
A bug has surfaced.
The new TelosB motes do not identify with a unique serial number on the USB bus. The unique ID should still show up in radio communications where it is taken directly from the id chip (I suspect). The brand new EEPROMS which should contain the serial number and identification string for USB identification purposes, however, are factory floor blank, and so the ID reported via USB is (none). With luck someone will have an initialization program which will allow the MCU to program the EEPROM. Without luck we will have to write one ourselves.
We are in the final stage of manufacturing for the first run of Telosb motes. In what is hopefully a positive sign, the first mote off the line took the blink program with no difficulties.
Notes from this data collection:
room 1 = bed mote 165
room 2 = bed mote 167
room 3 = bed mote 166
hallway = pyramid 200
exp started
2:45 – 2:47 set pager by pyramid (around mote time 3000)
2:47 – 2:52 pager in “far” positions of room 1
2:52 – 2:57 pager in “near” positions of room 1
2:57 – 2:59 set pager by pyramid
2:59 – 3:04 pager in “far” positions of room 2
3:04 – 3:09 pager in “near” positions of room 2
3:09 – 3:11 set pager by pyramid
3:11 – 3:16 pager in “far” positions of room 3
3:16 – 3:21 pager in “near” positions of room 3
3:21 – 3:23 set pager by pyramid
3:23 – 3:33 pager in hallway, out of rooms
3:33 – 3:35 set pager by pyramid
From the data collected:
In Room 1 from: 3214-3777
In Room 2 from: 3921-4507
In Room 3 from: 4658-5233
In Hallway from: 5287-5892
Analysis:
From this graph, we see a clear distinction when the pager was in room one. There are a few data points that are lower, but for the most part, it was clear that the pager was in room one from times 3214-3777.
Between the times that the pager was in the rooms, we see much higher RSSI values. However, there seems to be some odd values when the pager was in the hallway (at the end of the experiment).
Among the rooms, room three also has a clear distinction, but things get messy with the hallway signals.
From this graph, we see almost no distinction from in the hallway/ in the rooms.
The 2×2 Tables:
More Statistics:
In this version of the new puck, the FSR circuit has switch logic that can be controlled either by a digital potentiometer (that will be controlled by software on the mote), or manually by a trim pot. For now, we are bypassing the digital potentiometer (using the jumper, connecting pins 1 and 2). In the future, we will utilize the digital potentiometer which interfaces to the digital I/O pins on the mote. We have decided that the following interface will be used:
We now have 2 Irene motes (sans accelerometers and rtc) and 2 programmer/chargers completed, and have successfully installed Blink on them.
USER NOTE: To install to the Irene place the base switch into ‘prog’ position, and use: make epic install miniprog
Dev note – After multiple suppliers failed to ship the MIC5235, I substituted the MIC5205 for U8. This will have no effect on circuit operation.
F Antenna:
F Antenna with Metal Backing:
The graphs are very similar at close distances (.5 m). At farther distances (2.5 and 3 m), there are differences in the signal strength. If we aren’t concerned about the farther distances, we could still put the bed motes on the metal panel.
The battery test for the door minder is finally done. The total time has been 544 hours (that’s a little over 3 weeks!). At the end of the test, the battery voltages were 2.88v for the receiver (2 AA’s), and 3.12v for the transmitter (3 AA’s).
It seems that fully charged, each pager can last around 22 hours (86,000 seconds). This was found using the flash data from the weekend test of the pagers.
Powered by WordPress