Mindboards

Just a quick note to thank all those at Mindsensors who worked on the Mindsensors SensorMUX.

The soon to be released Mindsensors SensorMUX, is a multiplexer which allows the connection of 4x NXT Sensors to single NXT port. The Mindsensors SensorMUX can connect any sensor designed for Mindstorms NXT, both LEGO and/or third party sensors.

I am really impressed with the Mindsensors SensorMUX, and its capabilities. It is a must have for all serious LEGO Mindstorms NXT users. It is especially useful when using multiple analogue sensors, such as combining Touch and Light Sensors as I did in this project LEGO Mindstorms NXT Bin Emptying Robot – Mark III.

My next Mindsensors SensorMUX project is to get some RS-486 Sensors, including the NXT2WiFi Module and NXTBee Modems multiplexed through the NXT's High Speed (RS-486) Port #4. Not much more than a month ago, I was wondering how I could achieve this feat, but Mindsensors have saved me the loss of sleep on this one....

A big thanks also goes out to Xander Soldaat for producing the RobotC Programming Language Third Party Driver suite. Also for his quick response to fixing the BUGS I uncovered in his Mindsensors SensorMUX Driver. It's all part of the fun and frustration associated with BETA TESTING new LEGO Mindstorms NXT Sensors and other add-ons. I just love it!

interesting design, indeed!
seems to be sort of a multi-switch port-splitter which just plugs a muxport directly to the NXTport by switch and unplugs all the others at the same time.
If I see through that correctly, one can plug also i2c devices with different and identical device adrresses (e.g., 0x02) as well as custom i2c sensors with read/write functionality (e.g., USS in ping mode and max127 based analog multiplexers at the same time) which currently are not compatible to the HT sensor muxer.
Maybe one even can plug up to 4 HT muxers to each muxport.

Just curious about the timing behaviour for identical or mixed sensor types.

As it seems to be just a switch without computational intelligence it's probably also compatible to future "real" i2c hispeed mode (400kHz).

Surely very promising also for the EV3 in future!

Helmut,

You can find some additional info about the SensorMUX here: http://botbench.com/blog/2013/03/15/com ... nsormuxes/

As for using 400KHz I2C, I don't know. The SMUX forms a transparent channel to the connected sensor. I doubt it has been tested with 400KHz signals. I highly doubt you will get that kind of speed from the EV3 as well.

= Xander

Xander,
thx for this information.
Admittedly, " forms a transparent channel to the connected sensor" sounds better than "sort of a multi-switch port-splitter which just plugs a muxport directly to the NXTport by switch and unplugs all the others at the same time" but that's actually what I wanted to express.

But regarding the absence of a foolproof network for sensor remote multiplexing it now opens new dimensions for single-Brick-architectures when combining it with additional HTMuxers:

1 MSMux + 1 HTMux = 4 Lego sensors + 3 custom sensors at 1 port
1 MSMux + 4 HTMux + 2 HTTouchmux = 14 Lego sensors + 8 Touch sensors at 1 port (2 TouchMux at 2 SMux channels!)
1 MSMux + 1+1+1+1 MSMotorMux = 8 extra NXT motors + 3 custom sensors at 1 port (MotorMuxers daisy chained)
1 MSMux at port4 = + 2 custom sensors + 2 rs485 sensors at 1 port

overall:
18 Lego sensors + 8 Touch sensors + 8 custom sensors + 2 rs485 sensors + 8 extra NXT motors

that's maybe slow, and expensive, but nice for 1 NXT and that's about what I need... ;)
Almost a pity that the EV3 now has been announced... :)