FSAE 2014 Electric Race Car

Today we worked on the charger. We wanted it more user friendly. Having it more "automated" allowed me the safety officer and head electrical engineer for the project not have to be there to charge the pack up. We were lucky to find a power supply at our school that would allow analog signals to control the charger. We have been trying to get the DAC's on the control board to work. Getting I2C to work on the dsPIC is not fun. We are also interfacing with a 4D 4" display to show battery info. More work needs done on the algrorithem but it is close. 

One thing we are working on is a RS485 bootloader for the car. This will detect multiple devices and upload sequentially to one or all boards at once. This will allow for better software updates without having to take the car apart! Wish us luck! 

So one issue we had at comp is a little relay chatter. I thought it was battery issues and let it go for the time. We got back and it was really annoying me. So I pulled the safety board out of the car and ran some tests on it. Come to find out the issue rose its' head w/o relays attached. It had to do with our ~5 second precharge timer. We had a R/C timer go into a opamp with a pot to set the device as a comparator.  I am guessing the op amp didn't have enough open loop gain to go from low to high cleanly. So we got this high ringing on the output. We fixed this with a pull up and pull down resistor in the precharge system. 

So we have been working on motor repair lately and some software upgrades. We were checking the timing of our two motors and found that one brush got damaged. We are still waiting for a replacement. While we are waiting on the brush, Our software guy was busy on updates to the car and adding features. More to post soon.