# Franka Panda Setup

## Overview
This page contains instructions for setting up the Franka Panda arm with perls2.

## perls2 + Franka Panda Infrastructure

![panda_infra](../images/perls2_franka_simple.png)

perls2 uses three machines to communicate with the Franka Panda. These machines are connected in a local network. They consist of the: 

1. **Franka Master Controller**: This is the main control box that comes with the Franka Panda. 

3. **Workstation (WS)**: The workstation hosting the perls2 environment and running any scripts to perform  the robot experiment.

2. **Control PC (NUC)** or other computer with RT-PREEMPT Kernel: Typically an Intel NUC, is dedicated to running only the processes necessary for torque control. 

	Using the Franka Panda arm with torque control requires a consistent control loop frequency for sending torque commands to the arm. In order to acheive this, a separate machine with an RT Kernel sends torques to the Master Controller. 

	The following processes run on the NUC: 

	1. **redis-server**: An in-memory database used by perls2 for interprocess communication. Hosted on the NUC and communicated with via tcp. Allows the `perls2.PandaCtrlInterface` to bridge the `perls2.Env` on the WS with `libfranka`. See the [Redis Help](redis.md) for more on Redis and perls2.
	
	2. **franka-panda-iprl driver**: A redis wrapper for the `libfranka` driver. Sets redis keys for robot state, and gets torque commands computed by perls2 controllers from redis.
	
	3. **perls2 PandaCtrlInterface**: Process that implements the robot controller. 
		* Robot commands and controller params are obtained from the WS. 
		* Robot state is obtained from the franka-panda-iprl driver. 
		* The `PandaCtrlInterface` uses these to 	calculate the torques required to acheive desired
		robot state, and sets these to redis for the driver to send to the FCI. 


## Set up infrastructure
1. Follow the [instructions here](panda_nuc_setup.md) to setup the NUC

2. Follow the [instructions here](panda_ws_setup.md) to setup the Workstation.

3. Run a demo by following the [instructions here](panda_instructions.md) to use the Franka Panda with perls2. The Gravity Compensation demo is a good place to start.

    ```
    python demos/run_gc_demo.py --world=Real
    ```
You can try [other demos](demos.md) with the command line argument --Real as above.