Adding Mag Strip DetectionTo test a mag strip system just start the robot with the strip in detection position, and it will immediately pull back, same as if started with the optical sensors off the edge of a table.
In case of use some info on Neato Robotics mag strip sensor with component ID is at
http://www.robotreviews.com/chat/viewtopic.php?p=131834#p131834Small stick boards with ends in wells in the bottom of the case. They need to be close to a mag strip to sense.
Output was found 2v quiescent and 4v when detecting.
Note the Neato mag sensor adds a ferrite antenna material bar to concentrate the field onto the sensor component.
Your own sensor construction might use different outputs than the Neato sensor, but they are available used on
ebay in case of use.
The Neato cliff sensors (probably different than Samsung's) were interfaced to an optical signal detector at
http://www.robotreviews.com/chat/viewtopic.php?p=116780#p116780The sensors analog output rises the closer to the sensor, so for a cliff the signal is grounded by replacing it with output of an op amp (I use one working good on 5v single power supply). Never manipulate directly the optical sensor output as sensitive to voltages and can be damaged. A comparator is set up to go active low (typically open collector outputs, with pull up resistors when needed) when a boundary is detected, to short out the op amp output in a resistor network, a trick for digital logic input manipulations without actual logic gate components, 7400 series etc.
The example above is for an active low TSOP detection, so the comparator would just be rearranged for the active high input from a Neato mag sensor. Again comparator useful on 5v supplies. There is a need for hysteresis feedback circuits sometimes with comparators, omitted in the above example by mistake, using slowly changing input signals, where the output is unstable very close to the crossing point of detection; you yank the input across the boundary with the output on the first switching action, using points on resistor networks. I can give examples if needed. So if you are detecting a rising input on the negative comparator terminal, and the crossing switches the comparator output low, a feedback resistor to the divider making a reference voltage on the positive terminal can lower it a bit to solidly get a switch. About a 10mv difference is sufficient with the TS912 I use. Comparators vary in their precision. Of course, various latching circuits can be constructed with such feedbacks.
Incidentally I crudely make compact circuit boards with 30 gauge wire wrap wires on the back of perfboard instead of making proper printed circuit boards expensive. Messy sometimes with lots of connections. Perfboard cuts easily with fine toothed hack saw.
Given that certain black carpet materials have proved to make phantom cliffs absorbing the proximity sensor IR beam, it might be possible to make boundary strips of some black material. Unfortunately most common black materials reflect well in IR. Only certain carpets are a problem, some from Ikea, I don't know which. I even tried some IR stealth paint which did not work (not the most expensive kind). A product based on this effect was once sold for Roomba but had mixed reviews. "Keep Off"pads and strips.
Of course, with some additional circuitry on the sensor output it might be possible to recalibrate the sensor to work with some available black material, but dubious as it must work on the normal cliff situations as well -- if you have any cliffs. Industrial robots and lawn mower robots detect current in buried signal wires.
Other Samsung Technical AnaysisFor other technical data on Samsung I did some analysis of the suction fan at
http://www.robotreviews.com/chat/viewtopic.php?p=136798#p136798Elsewhere in that thread also experiments removing the cyclone extractor to increase suction -- not recommended in the end, the cyclone works good (and the max power mode is not needed, from pick up measurements -- nice it automatically goes on with the dirt detector; besides, the extra motor load may increase wear on the battery, not setup for that current level). This was on a 9250 higher power model. You see, member third_deg, Roomba designer pointed out earlier that the cyclone extractions systems take at least 20 per cent of the suction power from the motor. He doesn't like them, but I like washable filters -- a lot.