The N.M.E design team met to continue working on the printed circuit board. From previous testing we encountered a problem involving the datalogger and LM34 Temp. sensor. During the week, our group received the new components and tested them to our circuit. The new datalogger and LM34 operated successfully!
Once our N.M.E. design team completed that issue, we began applying epoxy to the designated areas of the R/C car where we were going to place the Thermocouple and LM34. Epoxy was applied around a hole that was drilled in the exhaust pipe where the thermocouple would be inserted. The LM34 needed to be placed on the head of the carburetor, so epoxy was applied near the bottom coil of the carburetor. Once the epoxy was applied it needed to sit for several hours so it can completely dry. The designated areas that the Thermocouple and LM34 were applied too were placed according to the temperature accuracy of those specific areas.
As we let the epoxy dry, we started modifying our .spin code. We needed to derive a code to monitor our servo controlling the R/C’s throttle response. We achieved this by using the ServoInput Object that uses one of a cog's counters to continuously poll an R/C servo control signal and store the pulse width in microseconds. On our board we set up 3 pin connections directly to the propeller chip to monitor the throttle response of the servo. For the throttle response to be correctly displayed on our datalogger, we had to connect one of the channels of the R/C’s receiver to be connected in series with a 10Kohm resistor to one of the pins of the propeller and of course the red wire to +5v and black to ground. First, we tested our code on a VGA monitor to make sure our board was properly monitoring the receiver’s throttle response. Once we saw that it was functioning correctly we revised the .spin code to record the throttle response to our datalogger. The range of the R/C’s throttle response (in decimal) was 800 to 1500 and 1200-1300 being in idle position.
Display of R/C receiver's throttle response (Full Throttle)
Display of R/C receiver's throttle response (Full Brake)
Display of R/C receiver's throttle response (Idle)
Picture below shows the area where epoxy was applied to hold the LM34 Temp. sensor on the bottom portion of the carburetor
Picture below shows the drilled portion of the exhaust pipe where the Thermocouple will be placed.
Picture below shows the finished product of the Thermocouple insertion into the exhaust pipe
Pictures below shows the carburetor dissassembled from R/C chassis (displayed from left to right)
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