Wearable SensorsBi-Weekly Report13 April 2004Table of ContentsSensors Team ................................................................................................................ 3Temperature Sensor .................................................................................................... 3GSR Sensor ................................................................................................................ 3BVP Sensor ................................................................................................................ 3Sensors Team Remaining Tasks.................................................................................. 4Board Team................................................................................................................... 5Board Team Remaining Tasks .................................................................................... 5Software Team .............................................................................................................. 6Chipcon-Cygnal Communication (Leader- Clay)......................................................... 6USB – Board Connection (Leader- Adam) .................................................................. 7GUI (Leader- Daniel).................................................................................................. 7Sensor Data Acquisition (Leader- Josh)....................................................................... 8Testing and debugging the Chipcon communication software (Leader- Josh) .............. 9Sensors TeamTemperature SensorSince our last bi-weekly report, we have recalibrated the temperature circuit with the3.5V battery supply. The linear relationship still has remained constant, but the constantof multiplication changed according the smaller input voltage. It should be noted that thetemperature on the surface of the skin is approximately one degree Fahrenheit lower thanthe average oral temperature. Our calibration has taken this into account.We have also made a design decision to attach the temperature sensor to the tip of theindex finger with a small Velcro band to securely hold it in place.GSR SensorWe have successfully implemented and calibrated the GSR. The skin resistance isrelative to each individual and an initial zero or baseline value must be established foreach person. Our circuit easily handles this design constraint. We have also decided thatthis sensor will be placed on the ring finger with the Velcro band.BVP SensorWe have successfully modified the circuit to operate on the 3.5V battery supply. Tosolve the motion artifact issue, we have decided to implement two identical circuits, onethat will measure BVP values, the other will only detect the baseline values. We willthen use software capabilities to subtract the motion artifact from the output resulting in aclean signal.Sensors Team Remaining Tasks• Design the three sensor circuits on Eagle software (Leader- Gouri)• Order the parts for sensor board population (Leader- Rosy)• Submit order for PCB manufacturing• Populate the board• Test and debug the board• Implement it with the transmission board• Write the software for the subtraction of the BVP signalsBoard TeamThe board should be arriving on Monday, April 12, 2004. Christina and Clay will beworking on populating the board with the parts that have arrived from Digikey. This taskshould be completed by Wednesday, April 14, 2004. After the board has been populated,the board team (which consists of Clay, Christina, and Adam) will be working together tocombine the sensors board with the transceiver board as an immediate task. Theremaining tasks for the board team are as follows:Board Team Remaining Tasks• Complete population of the transmission board with the ordered parts. (Leader-Christina)• Combine the transmission board with the sensors board.• Test and Debug system.• Combine the boards with the transmission / receiving software.• Test and Debug system.• Combine system with GUI (graphical user interface).• Test and Debug entire system.• Integrate system into wearable device (wristwatch)• Project completion.Software TeamThe software team, which currently consists of Josh, Daniel, Adam, and Clay, has beenworking toward the following goals.Chipcon-Cygnal Communication (Leader- Clay)Successful communication between the Chipcon and Cygnal processor working. Belowis a list of our debugging steps:1. We first hooked up the boards to the EB63, and determined we could read andwrite registers from the Chipcon daughter boards. This verified that the old codewas working and that at least one of the daughter boards could send and receiveusing serial communication.2. We then swapped out the first daughter board (board 1), for the second (board 2)to see if it was in working condition. When we plugged it in, it did not work. Wethen plugged the other board (board 1) back into the computer to see if we weremissing something. It did not work. Unfortunately that was when we noticed wehad a pin that was set to Vcc, that was not supposed to be set. Our next step wouldthen be to see if this error had fried the serial communication capabilities of boththe daughter boards.3. To determine if our theory was correct, we went ahead and placed both of thedaughter boards back into the Chipcon motherboards, and proceeded to check tosee if we get them to communicate using the software we got from themanufacturer. The boards worked perfectly. We were able to get both boards tosend and receive without any CRC errors.4. We went back to check our connections on the ChipCons to see what was causingthe issues found in step 2. We first decided to simplify the number of pins beingplugged into the board, by soldering all of the ground pin wires together so thatwe just had to plug in one cord. We did the same for both power supplies. Nextwe looked at the code to see what was occurring when the program ran. Wesimplified the read procedure, and verified the write procedure. Next we hookedup a logic analyzer and found quite a few errors with the code. The errors foundthrough this debugging process have now been fixed.After all of the commands, timing requirements, and voltages were checked, we stillcame up short, and the ChipCon is still not responding to commands.Our Theory: We believe we fried one of the buffers on the ChipCon, thereby preventingserial communication from occurring.