Force Sensor Wireless Solution

Help & Support Robot Parts
1

Hi friends,

I’m an outsider with a management science background looking for a solution into a technical matter I can’t resolve by scouring the net. I am working on an academic project that will allow me to track multiple pressure or force points and have that information transmitted wirelessly to my computer in a real cost-effective scalable way.

For example, there are 100 locations and I want to implant a mini sensor underneath each one (say underneath the carpet). I’m not concerned with the impact having to hit the sensor directly. I just care about if the specific point is occupied or not occupied–if it could determine the weight that would be good too, but mainly I’m just concerned about the occupied vs. not occupied status.

I have seen these two following products that look promising:
futek.com/product.aspx?t=force&cat=fp&m=ffp350
phidgets.com/products.php?product_id=1131.

These products seem pricey, especially the first one. The second product only seems to be analog and USB. There’s also this loadstarsensors.com/vmchk/rsb5-di1000u-lv4000-rsb5-subminiature-load-cell-kit-and-software.html, which fits the criteria for what would probably work but is again too pricey.

Any ideas on how I could implement this or other resources I could use? The wireless requirement is integral. I can’t really find any overseas vendors either.

Thank you,

ForceSensor

3

Hi ForceSensor,

Welcome to the RobotShop Forum. 100 x $395 is pricey, though $14 each is much better. If you can hook up multiple sensors to one wireless point it would save you a lot of time and money. If each sensor needs to be wireless, you’ll need the sensor, a microcontroller and a transmitter. Let’s assume you can connect several units together, the first category you should consider is Contact and Proximity Sensors. You can use any of the Interlink FSRs and connect them to analog pins on a microcontroller (you would also need a small voltage divider circuit, which is as complex as adding a resistor to each sensor; the FSR is the other resistor). Since most microcontrollers don’t have 100 A/D pins, you would need additional ADC, such as those provided by the Analog / Digital MUX Breakout Board. You would certainly have enough digital pins if you used the Arduino / DFRobot MEGA microcontroller. The corresponding MEGA protot shield would help with connections, and also has an XBee slot for sending data wirelessly. On the receiving end, you would have another XBee and a USB to XBee breakout board to connect to your computer.

Hope this gives you some ideas,