Hi!
Is it possible to have a controller collect sensor data from 20,000 sensors? What I want is thousands of arduino-sensors in a room, all taking some measurement of the temperature, and reporting to a hub/controller (arduino or rapsberry pi) which in turn relays that info using a GPS-shield to a web server. I'm hoping it can be done with some cheap RF/wifi transmitters. Using for example bluetooth can be pretty costly if multiplied by 20k.
Yes, but I guess you can buy in bulk. Who knows? maybe $1 each - only $20 000.
Thousands of Arduinos will cost $20 each for real Unos.
What I want is thousands of arduino-sensors in a room
Must be one hell of a big room.
and reporting to a hub/controller (arduino or rapsberry pi)
After spending in excess of $40000 for Arduinos and sensors and wiring (or $60000 if wireless is necessary), sending the data to a puny ass microcontroler makes NO sense.
I'm hoping it can be done with some cheap RF/wifi transmitters.
Not a hope in hell.
PaulS:
Must be one hell of a big room.
Not really.
PaulS:
After spending in excess of $40000 for Arduinos and sensors and wiring (or $60000 if wireless is necessary), sending the data to a puny ass microcontroler makes NO sense.
What would make no sense is paying more for a controller if it wasn't necessary. Not saying it isn't.
PaulS:
Not a hope in hell.
Thanks for that constructive feedback.
Use ESP 12 modules to talk across Wi-Fi? theyre about $3. I even remember a comment about them along the lines of they're cheap enough to throw hundreds of them into a room.
Arduino draw ~50mA x 5V = 0.25W; x 20.000 = 5 kW A lot of power for a room
assuming that 20K is a bit exaggerated, Im going to try to answer if it were a 128 sensors, hardwired to an arduino UNO with the use of certain I/O expander ICs.
Yes you can! You can connect all your sensors to analog multiplexers. An analog multiplexer can have 8 incoming analog sensor signals, and with 3 digital control lines you can select 1 of these 8 lines to be connected to an analog input or to an other multiplexer.
so with 6 analog inputs you can hook up 6 x 8 analog sensors. You can also make an entire tree of these multiplexers so you can hook up infinite sensors to a single analog input.
As every single mux IC needs atleast 3 digital control signals, you need to use other I/O expanders to control them. You can use shiftregisters and make an infinite long chain of digital outputs for your infinite ammount of mux. Or you can use I2C I/O expanders such as the MPC23017 to control your all your mux.
If you want wireless sensors only, you could set up a netwerk of Xbees (I have no idea how many you can put on a single network). Or perhaps you can use those 5 buck cheap radio transmitters and write your own protocol for the communication between your UNO and the 128 attinys. You will need 2 way traffic so every attiny needs an receiver and transceiver. You can let the uno transmit a number like 27, where only attiny #27 will respond to and sends his sensor data.
But eh brah, can you be more specific in what you actually want to build or set up?