Meeting Log Spring 2010
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January 13th
This was first meeting of 2010. This week we populated most of the Atmel board and look to populate the rest before next weeks meeting. During the construction of the PCB board we noticed that some parts have gone missing, most likely due to the time we took to construct the boards. We placed an order for some new parts and they should arrive before next weeks meeting. This will leave us with the programming and construction of the Sumo-bot itself for next weeks meeting.
-This years goal is still in the picture, in which we hope to enter either (hopefully both) the PIC or Atmel into the robogames competition which takes place in California.
January 20th
This week we got a window comparator [1] circuit layout and tested. The reason for making this circuit is to use the comparator circuit for the IR sensors the monitor the outside sumo ring. The circuit worked as planned however it took a little while for the micro to realize the op amp [2] is putting out a high voltage so we modified it a little. Basically just got a faster op amp and the results improved dramatically. We finally finished soldering the board and before powering up we read through the schematics of the board layout and encounter yet some more problems with the board.
Problems with PCB
1st- From switch to a dip to a flat pack micro there are additional VCC and GND lines that did not get taken into consideration. 2nd- Another switch from a PIC [3] micro to an atmel [4] we forgot to include the external crystal. 3rd- After further research we found that by adding the comparators to monitor the lines of the sumo. This requires less code and will likely operate more efficiently then monitoring them using an ADC from the micro.
January 27th
After getting such good results from the window comparator circuit. We are taking into consideration another window comparator circuit for the monition sensors that detects another robot. You may ask why are you using window comparators. The reason is that window comparators can give out a high or low voltage instead of a varying analog voltage that would need to be converted for the micro to be able to read. The down side of using a circuit like this is it can take additional time for the micro to read the voltage from the op amp. The way around this to get a fast op amp. There was also some further coding that took place on the micro. We feel after so many mistakes on the PCBs in the past. That the best approach is to breadboard and program everything first and after becoming satisfied with the results we will place the order for a new PCB. Until breadboarding and construction of Oscar will take place.
