Merge branch 'master' of

ssh://gitlab.cba.mit.edu:846/rcastro/atkbbbd_rmec

README.md

-This works
\ No newline at end of file
+Hello!
+This is my first attempt at a circuit board. It shall hold an H-bridge for 
+motor control, current sensing, and SPI pins for encoder implementation.
+It is a board that revolves around the DRV8701 (http://www.ti.com/product/DRV8701) 
+gate driver chip. The DRV8701 is capable of driving a varied set of MOSFETS.
+Chosen here are the AON7410 MOSFETS.
+
+Design Rules:
+-5A continuous/10A peak rating
+-0-10A to 0-1.5V mapping current sensing
+-12V Motor
+-SPI breakout for encoder
+-Not hotter than 70C
+
+
+DRV8701 Rules:
+Vgs(voltage applied to MOSFET gate) = 9.5V
+Ivcp(current capable of being applied to MOSFET gate - dependent on Vm) = 12mA  
+20v/v conversion for current sense - for 0-10A to 0-1.5V mapping, you need a ~7 mOhm resistor rated for >=2watts
+Lots of passive components need to be around the IC.
+
+Basic definitions I learned in the process-
+Bulk Capacitor - Capacitor used to be capable of taking over battery in certain sags. It is
+    set as close to the input as possible. In this case an electrolytic >=10uF.
+Decoupling Capacitor- Capacitor used to give power to certain components or devices
+    similar function to bulk capacitor, except placed near individual components.
+    Like a local bulk capacitor.
+Rsense -Shunt Resistor used for current sensing on the low side of the h-bridge.
+    In this case- 7mOhm. Current can be measured by taking the difference between
+    each side of the resistor to measure voltage drop, then V=IR
+Net Ties- Just like a trace, except its meant to be isolated from other traces or
+    pours around it. Used here for Rsense, where we want to measure difference
+    between ground and the voltage before the resistor, but we want the traces
+    to look about the same and not be impacted by differences in voltage around it.
+
+Kelvin Connection- Way of connecting traces to Rsense. It just makes sense
+    Take it for granted. Google how to do it. It's very simple.
+
+PCB guides:
+45 degree traces only
+Kelvin Connection for Rsense
+Always have a ground plane.
+Try to be as symmetric as possible
+Differential pairs routing for pairs of traces.
+
+
+
+
+
+
+