Howdy All,
I've just released the project contents of my Maxbotix EZ1 sensor controller board. The maxbotix EZ1 is an ultrasonic sensor that measure distance to any object and reports it. It's inexpensive and pretty small. However, it puts out a steady stream of messages which can present a load on a computer or controller to keep up.
My controller acts as a front end and provides the following:
* Can be told to send an update only when there is change (and you can control how much of a change before an update is sent).
* Can be told to monitor an area within the measuring range and inform when something moves into out of range
* Can manage up to 12 sensors, allowing 12 sensors to use only a single serial port
* Because only one sensor is turned on at a time, multiple sensors can be in close proximity to each other without interference (if you run them all the same time and they are close by, they can intefere and through off measurements).
* Because the interface is RS232, it allows you to put the sensors at considerable distance from the computer/controller (the sensors use a faux RS232 level that can get weak over longer runs).
The controller is pretty easy to build -- you need two chips and 6 capacitors for a single sensor controller. For a 2 or more controller, add a diode per sensor and a single resistor (just one, no matter how many sensors). You can prototype the thing in about 15 minutes on a bread board and wirewrap one in about 30 minutes.
The serial control protocol is a simple text protocol that is well documented and easy to use. It has features that should make integrating it into HA controllers fairly easy as well as having lots of details available for integrating with computers. Finally, it include an xPL gateway that allows measurments to be broadcast on the local LAN and allows control over the sensors via that same LAN (it's optional, of course).
Also, while not yet available, I do have a PC Board in manufacturing. It allows 1 to 4 sensors on the board (I had to pick a good median number). When they arrive, I'll be making a kit available that will include the board, a pre-programmed PIC and all needed connectors and other parts. Probably about 2 weeks out. However, everything you need -- schematics, PC Board layouts, documentation, firmware, etc are downloadable so you can create your own PC Boards if you'd like.
You can read more about it at http://www.rgbled.org
Gerry
I've just released the project contents of my Maxbotix EZ1 sensor controller board. The maxbotix EZ1 is an ultrasonic sensor that measure distance to any object and reports it. It's inexpensive and pretty small. However, it puts out a steady stream of messages which can present a load on a computer or controller to keep up.
My controller acts as a front end and provides the following:
* Can be told to send an update only when there is change (and you can control how much of a change before an update is sent).
* Can be told to monitor an area within the measuring range and inform when something moves into out of range
* Can manage up to 12 sensors, allowing 12 sensors to use only a single serial port
* Because only one sensor is turned on at a time, multiple sensors can be in close proximity to each other without interference (if you run them all the same time and they are close by, they can intefere and through off measurements).
* Because the interface is RS232, it allows you to put the sensors at considerable distance from the computer/controller (the sensors use a faux RS232 level that can get weak over longer runs).
The controller is pretty easy to build -- you need two chips and 6 capacitors for a single sensor controller. For a 2 or more controller, add a diode per sensor and a single resistor (just one, no matter how many sensors). You can prototype the thing in about 15 minutes on a bread board and wirewrap one in about 30 minutes.
The serial control protocol is a simple text protocol that is well documented and easy to use. It has features that should make integrating it into HA controllers fairly easy as well as having lots of details available for integrating with computers. Finally, it include an xPL gateway that allows measurments to be broadcast on the local LAN and allows control over the sensors via that same LAN (it's optional, of course).
Also, while not yet available, I do have a PC Board in manufacturing. It allows 1 to 4 sensors on the board (I had to pick a good median number). When they arrive, I'll be making a kit available that will include the board, a pre-programmed PIC and all needed connectors and other parts. Probably about 2 weeks out. However, everything you need -- schematics, PC Board layouts, documentation, firmware, etc are downloadable so you can create your own PC Boards if you'd like.
You can read more about it at http://www.rgbled.org
Gerry
