I started a home project which has become almost impossible i think and its all my own fault!
I planned on using a raspberry pi to monitor around 80 analogue sensors - specifically force resistors. I have since learnt that to use these sensors i need;
1) an analogue input on the raspberry pi - which i dont have 2) i could use an analogue to digitial converter which would then lose any information from the sensor
Step 2 is not desirable because i want to know when a sensor is above a particular value so based on this what are my options
Have I been far to optimistic and should i maybe swap the pi for an arduino or something? Is it ever possible to hook roughly 80 of these up to something so small? Hopefully someone can provide some assitance
The sensor type can be seen below - ideally all i want is to be able to read all 80 sensors and tell when a sensor is over a certain force. I dont need to know the force, just that it has been surpassed.
This is a force sensitive resistor with a square, 1.75x1.5", sensing area. This FSR will vary its resistance depending on how much pressure is being applied to the sensing area. The harder the force, the lower the resistance. When no pressure is being applied to the FSR its resistance will be larger than 1MΩ. This FSR can sense applied force anywhere in the range of 100g-10kg. Two pins extend from the bottom of the sensor with 0.1" pitch making it bread board friendly. There is a peel-and-stick rubber backing on the other side of the sensing area to mount the FSR. These sensors are simple to set up and great for sensing pressure, but they aren't incredibly accurate. Use them to sense if it's being squeezed, but you may not want to use it as a scale.
I want to detect when a seat has been sat on, but want to only show something that would be heavier than a bag. Thats why my condition of over a certain limit comes in to it. Ideally the cables connecting the sensors wont be too long, a couple of feet max i guess.