Added 2017-2018 mars rover repository.

OSU Robotics Club/Mars Rover 2017-2018/electrical/documents/nodes/grasp.md

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+# Grasp Node
+
+![Grasp Node](https://github.com/OSURoboticsClub/Rover_2017_2018/blob/master/electrical/documents/nodes/files/grasp.JPG)
+
+Designed by [Dylan Thrush](www.dylanthrush.com).
+
+## Summary
+
+Made for MR1718 as part of the OSU Robotics Club.
+
+Controls 4 DC motors with quadrature encoder and current feedback. Has four analog inputs intended to be used with force resistors.
+
+### Bill of Materials
+
+[Bill of Materials](https://docs.google.com/spreadsheets/d/1zSJRJATg0B-pW4RrPtu3-lWw_H9taLzccoVNc3EoKm8/edit?usp=sharing)
+
+#### Design files
+
+[MR1718 GRASP on CircuitMaker](https://workspace.circuitmaker.com/Projects/Details/Dylan-Thrush-2/MR1718-GRASP)
+
+### Downloads
+
+[Schematic V1](files/grasp-v1-schematic.pdf)
+
+[3D Model V1 (STEP)](files/grasp.step)
+
+### Firmware Info
+
+#### Pinouts
+
+| Pin Name | Arduino Pin Number |
+| -------- | :----------------: |
+| PWM 1.1 | 25 |
+| PWM 1.2 | 22 |
+| PWM 2.1 | 23 |
+| PWM 2.2 | 9 |
+| PWM 3.1 | 10 |
+| PWM 3.2 | 20 |
+| PWM 4.1 | 5 |
+| PWM 4.2 | 21 |
+| Motor Current 1 | 16/A2 |
+| Motor Current 2 | 17/A3 |
+| Motor Current 3 | 19/A5 |
+| Motor Current 4 | 18/A4 |
+| Encoder 1A | 2 |
+| Encoder 1B | 30 |
+| Encoder 2A | 29 |
+| Encoder 2B | 27 |
+| Encoder 3A | 28 |
+| Encoder 3B | 12 |
+| Encoder 4A | 11 |
+| Encoder 4B | 13 |
+| Force 1 | A14 |
+| Force 2 | A13 |
+| Force 3 | A12 |
+| Force 4 | A1| 
+| Red LED | 6 |
+| Green LED | 32 |
+| Blue LED | 1 |
+
+### Known Issues
+
+#### Version 1
+- Missing 3v3 rail connection to VBAT pin on Teensy. Will program without it, but will not boot without it.
+- 12V switching supply GND is not connected to board GND.
+- Motor controller needs a thermal pad in the footprint, will not work otherwise because thermal pad is connected to GND. Scrape away silkscreen below package before soldering.
+- Motors 2-4 are still not working...
+- LED needs to be rotated 90 deg CCW for power pin to line up.
+
+#### Version 2
+- LSS for motor needs to be a star ground return to motor pad, short LSS to GND for normal operation