Updated node ducmentation for tower alt and grasping

electrical/documents/nodes/readme.md

@@ -7,8 +7,9 @@ The project contains the following nodes:
 - [IRIS](#iris-node)
 - [Motor](#motor-node)
 - [Tower](#tower-node)
+- [Tower Alt](#tower-alt)
 - Pan-Tilt
-- Grasping
+- [Grasping](#grasp-node)
 - Science
 - Arm Breakout 1 / 2
 
@@ -35,3 +36,19 @@ This node controls the motors that turn Rover's wheels.
 This node is placed outside of the main electronics box on the chassis and collects data from various sensors.
 
 [Find more documentation here.](tower.md)
+
+### Tower alt
+
+<img src="files/tower_alt_render.png" width="300">
+
+This board acts as an alternate for Rover's Tower Node when both of the boards we had didn't work. It really just breaks out a Teensy 3.2 to a few different connectors.
+
+[Find more documentation here.](tower-alt.md)
+
+### Grasp Node
+
+<img src="files/grasp.JPG" width="300">
+
+Controls 4 DC motors with quadrature encoder and current feedback. Has four analog inputs intended to be used with force resistors.
+
+[Find more documentation here.](grasp.md)