I hope someone on this forum can help me, although I can readily admit that my question isn’t directly related to robotics, but moreso RF communication.
First off, I should preface that while technologically proficient…I have no experience with electronic circuit building…so please be kind when trying to decipher my communication. I may/probably will not use the correct terminology often.
Onward - I am an occupational therapist and have recently been contemplating building some simple wireless devices to handout to my low-funds/low-access population. I work at a charity hospitable, where my patients consist of stroke/traumatic-brain injury survivors who not only have limited money but also very limited access to products outside of the local Wal-Mart. A large portion of my patients could benefit from a small device (RF Transmitter?) that they could clip on their shirt and activate a switch that signals an LED light that would be mounted in either a common room or perhaps one of those bracelets that have now become all the rage at concerts (Coldplay often uses them). So basically I’m trying to build a small/low-cost transmitter and receiver that acts pretty much like a nurses notification button on a hospital bed.
Most of my patients would like more privacy and providing them with a simple notification device could really free up the caregiver burden as well.
Can someone point me in the right direction as far as what all I would need to build or educate myself on to make this possible. I don’t care for any advanced function…that would actually be counter-productive. I literally need just a small switch that can wireless transmit signal through maybe a few walls to activate an LED. I’m assuming RF would be the best best for this overall…but in reality have no clue. Any suggestions on actual products or the process is welcome.
Sorry, no I wasn’t very clear. I was at work in between patients and typing quickly. I would like to build a small device that could clip on clothing and when triggered (some type of small button) sends a signal to a receiver to activate an LED light. The idea being if my patient fell within his home, he could press the button on the small transmitter and it would send a signal to their caretaker’s wristband. Honestly, I found this while searching about an hour ago and it’s pretty much exactly what I’d need. But I don’t need the flashing options (just LED on and off) and I’d like to decrease the size of the “controller” to something that could be clipped onto clothing (and with obviously only one button).
I imagine that RF would be the best form of wireless communication to utilize. IR doesn’t work because no clear sight and bluetooth would probably be too expensive, even though probably easier to build/program…although I’m not really sure about that.
Not sure if anyone has had a chance to contemplate my issue. I realize that this does not fall under the hobby/career of building robots but I thought it might be a good place to look. Please do not hesitate to point me towards other forums or sites, I assume y’all would perhaps be keen on where I could get the best help.
Simple RF communication should reach the 20M you desire although it will need to be increasingly powerful if there are many obstacles (especially metal ones) on its path. You could use this transceiver: RB-Ite-19
In order to control the transceiver and display alerts, you will need a wearable microcontroller such as the Lilypad. This kit might help you get started: RB-Spa-693
It comes with more parts than you need but you can use it to understand how you can design your device and chose which parts you will need to get individually.
Of course, this is a custom integration project and as such, the unit-price will be much higher than the finished, mass-produced product you could buy form a manufacturer.
What would be the range you require for your communication? would the care take be in the same house, same building?
RF would work well for a small rage or a longer range with line of sight. Regular Bluetooth would work for around 10m in range.
If you need any longer range than that, we recommend using the interenet as yoru communication method. But this would increase the cost of each of your nodes.
You could have a series of buttons that communicate with a local hub using Xbee, RF or BT. Than teh hub would communicate via the web (or directly if in range) to the bracelets. If this option interests you, we can elaborate further on how to do it.
That sounds like an interesting project. Before we can suggest a course of action, we would like to make sure we understood the concept correctly: you would like to build a device that (when in range of an antenna) will be able to signal the presence of a person carrying it. Is that right?
Is the indicator (LED) present on the antennae or the portable device side?
Sorry for late response. The range required would be minimal (20m would be more than sufficient most likely) and it would be within the same building (although no clear line of sight typically, a residential wall or two would be in the way).
I figured Bluetooth would not quite offer the range needed, as well as being more expensive, but is 20m too much to expect out of a realistically power RF? Since I don’t have access to the patients’ homes and the typical education level of my patient’s falls within the middle school range, I don’t want to get too complicated with a hub system or setup. I literally just want to be able to hand them a receiver (bracelet form seems ideal) and a small, simple transmitter/antenna.
Really the device I linked to earlier (alibaba.com/product-gs/835063851/RF_control_bracelets_with_LED_lights.html) is borderline perfect, except I just don’t need the extra LED modes (on and off is fine) or the 300m of range. So I’m hoping I could effectively build the same type of setup with a smaller controller (as I’m assuming since I would need less battery power). A controller with one button and one LED to alert that it was activated.
The minimum order quantity is 100 for that device and realistically I would be fine with 30 until I could gauge the satisfaction and fit for my patients’ lives. Looking at the quoted prices, if they would even let me order 30, I am confident it would be at the $4 a piece price range at BEST. I’m hoping I could build simpler ones at a lower cost per unit, but that might not be feasible in the small batch quantities I’d buy materials in.
