Need help if my project idea is possible and how to do it.

Hi Arduino forum.

This is my first post
I am about to start a project with the ARDUINO UNO REV3.

I was thinking about if it was possible to transmit data from a Force Sensing Resistor to the Arduino with two Bluetooth HC-05 Module one as master and one as slave. If not, what components is needed to make It possible?
Or is there another way you can transfer data without wire?
I have seen data transfer between two Arduino, but that won’t work with this project.

Thanks for any suggestions and help.

You cannot connect an FSR to a Bluetooth module and have the data transmitted. You will need a microcontroller at the FSR end of the link

I have seen data transfer between two Arduino, but that won't work with this project.

Why won't it work ?

Hi UKHeliBob

The project that i want to make is where there is a cushion covering the seating place on a chair. Then the cushion should have the FSR, and be available to detect when a human sits on the chair. Then this FSR need to send the data to the Arduino without a big wire going from the chair to the table. Then the Arduino need to turn a light on after 1 hour where human have been on the chair. But the thing i don´t know is what components is needed for the FSR to send data to the Arduino.
The cushion should also be quite low power consuming as the cushion needs to be on batteries.

But the thing i don´t know is what components is needed for the FSR to send data to the Arduino.

An Arduino and a Bluetooth module can be quite small, but if you were to use an ESP32 or ESP8266 then you would not need an external transmitter as they both have built in WiFi and could run a websever that you could connect to using a PC, tablet or mobile

Finding a suitable small battery may be more difficult

Are you absolutely sure that a wire, it need only be very thin, cannot be run from the FSR to an external device ? It would make life very much simpler

I just think that the wire would be very annoying and ruin the project.

But is there another way to make the project possible? with other components?

Send data with NRF24L01? or some kind of independent data reader and transmitter.

Yeah it is really also the battery there hard.

What sort of battery life do you want? Hours, days, weeks, ... ?

krusetm:
I just think that the wire would be very annoying and ruin the project.

But is there another way to make the project possible? with other components?

Send data with NRF24L01? or some kind of independent data reader and transmitter.

Yeah it is really also the battery there hard.

If you make the whole system run on 3.3 volts, a simple call phone battery would fit in a chair cushion.
Paul

Im a noob not gonna lie

The battery life i want is weeks but days would be fine for at start.

But i was texting with a person, and he got me thinking that my project wasn't possible.
I have really no idea how i would transfer the data from the cushion to the Arduino on the table without some kind of big battery on the chair.
If you guys got any ideas i would very much appreciate it.

Some notes:
There are many ways to do this; As many as there are members here
<$0.02>

  • Almost any radio will do, as your distances are very small. Go for a low power budget, and know which frequencies are OK to xmit on in your country.
  • Though not stated, should we assume A/C or constant wall power, is available at/on the table?
  • You could have a battery/unit charge included in the physical design of the table light, and just swap between them.
  • There are other ways to determine if there is a person (Infrared source) in front of a lamp (on a chair/couch), other than a self-powered remote sensor. An example is infrared, even a PIR sensor. Changing levels, lack of level above baseline, etc.
  • Consideration should be given for someone who simply gets up and leaves before their hour is up. Does it still fire? Will it fire early if someone else sits down?
  • Power is also likely available at/behind a couch/chair as well, which would power the ‘send’ side.
  • To go old school, you could easily fashion a ‘clicker’ that would issue a specific tone/chirp that a microphone on the light could sense. We used to control TV sets that way.
  • If you expect a sensor to be self-powered, and also be ready for a signal such as from a powered force sensor, your battery will drain quickly.
  • If you can fashion a mechanical switch that closes when it has pressure on it, then you can make a μC stay in deep sleep until it was woken up by a contact closure. It would then send a signal, and go back to sleep. I have a single 18650 and an ATTiny85 in this configuration for 2 or 3 years now.
  • Don’t worry about BT or WiFi if you want battery life, as they are power hungry protocols. Radios just transmit a few bytes to a waiting receiver, and shut back down efficiently.
  • Don’t discount other sensors, like floor/rug sensors, or even piezo ones o determine state…

</$0.02>
I think the radio communication mechanism is the easiest problem to solve.

Hi holesflow

Thank you so much for the detailed comment
"know which frequencies are OK to xmit on in your country."
Could you use multiple radio signals in the same room with multiple devices?
"Though not stated, should we assume A/C or constant wall power, is available at/on the table?" Yes there is power on the table.
Dont think that Infrared source as it could miss the person sitting there.
It should reset after 5 minutes, with no activity.
"Radios just transmit a few bytes to a waiting receiver,and shut back down efficiently." That sounds like it could actually work.
Do you have any idea, how i could transmit the data via the radio link? And a smart way to know then a person sits on the chair? maybe products.

Most people's butts heat the cushion they set on. Monitor the temperature and report an increase as being set on and a decrease as the person is gone.

I guess you are ignoring my suggestion to use a cell phone battery. They are rather thin and will fit your requirements.

Paul

Hi Paul

"Monitor the temperature and report an increase as being set on and a decrease as the person is gone."
Not at bad idea, but think the FSR would work better.
Sorry i didn´t respond, but i thought about it and the came to the conclusion that the cell phone battery, would be too expensive.

Just giving other options.

Who said anything about a "new" cell phone battery. My 10 year old flip phone battery still runs for a week on a couple of hours charging. What does a well used cell phone cost?

Paul

Hi Paul

Much appreciated, a new take is always good.

Based on yor questions, you might want to either start with some breadboard experiments and/or dig into here a bit: https://playground.arduino.cc/