Introduction to LXP

All LunaOS robots are required to provide LXP ports. 

LXP provides plug-and-play functionality for any 3rd party accessory, regardless of complexity. An end user should be able to plug in an LXP accessory and the host robot will recognize, install appropriate driver, and it should just work. 

An LXP port is made up of three standard components: a USB Port, a 12v regulated power port, and a 5v regulated power port. An accessory may use any combination of these components within LXP. For example, a camera may use the USB and 12v power.

All LXP accessories must be design-in the LXP Driver Model logic. This is a simple communication protocol that a) 

identifies, b) abstracts the accessory hardware, and c) reads/writes data packets to the host robot.

However, robot vendors and accessory makers are not limited to the LXP port. Anyone can make any interface on their robot and/or accessory. The purpose of LXP is to provide a uniform means for vendors and end users to have plug-and-play functionality on the robot.  

LXP Schema

The LXP physical specifications:

LXP Driver Model

The LXP Driver Model (LDM) is a uniform read/write protocol so that LXP Accessories can plug-and-play with the host robot. LDM is a software stack inside LunaOS that resides on top of the USB stack. 

Accessory suppliers will develop their own drivers, according to the LDM protocol. The LDM protocol is simply a uniform communication protocol that sends/receives data to/from the host robot. By providing this uniform method of communication, any hardware accessory can plug-and-play with the host robot, regardless of complexity, since the complexity is abstracted in the LXP Driver. 

LDM also includes an identifier. Similar to USB, when an LXP device is plugged in, the robot can read the ID string and find/install the appropriate driver(s) - perhaps through the web. To this effect, we propose the creation of an LXP SIG, which administers LXP ID Strings, modeled after the USB or Bluetooth SIGs.  

LXP Daughter Board

The LXP Daughter Board is an inexpensive board that provides an LXP interface and driver logic on one side and various interfaces (TTL, I2C, etc) on the other side. It is intended for hobbyists and small production runs, so that people can make LXP Compatible accessories with minimal effort and ultra-low cost. 

LXP Daughter Board Architecture Schematic	LXP Daughter Board Interfaces
	I2C Serial Analog Input 8 bit Analog Output 8 bit Various Digital I/Os   Note: vendors are free to design-in other interfaces as well.

All hardware schematics and firmware are available for download here. Additionally, while we expect a variety of vendors to make this card, RoboDynamics has committed to commercializing this card and its availability will be announced soon.