Short Flex Sensor

Wearable electronics: boards, conductive materials, and projects from Adafruit!

Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.
Locked
User avatar
Bipman
 
Posts: 14
Joined: Wed Jan 11, 2023 6:29 pm

Short Flex Sensor

Post by Bipman »

Hi

Thanks to support I now know about noise from the sensor so have worked that all out. I'm using a 5k resistor connected to the sensor via a 3.3 V Nano IOT, but the range is only from about 85-400. I presume just changing the resistor will make no difference to the range, is this range of output as expected? I thought I might get more of a resistance range from the sensor.

Steve

User avatar
barshatriplee
 
Posts: 200
Joined: Wed Mar 22, 2023 10:11 am

Re: Short Flex Sensor

Post by barshatriplee »

Since you are using a 3.3V board, 400 is normal I think. Because when connected to an Arduino UNO, the highest analog value is more than 900.
https://learn.adafruit.com/force-sensit ... ing-an-fsr

But 80 looks too much to be the lowest value. Because, when there is no external pressure, the value must be zero as far as I can see in the adafruit documentation. If it is possible, implement your circuit with an Arduino UNO or any other 5V Arduino. Thus, you can cross-check if the sensor is behaving as described in adafruit documentation.
Last edited by barshatriplee on Wed Mar 29, 2023 11:30 am, edited 1 time in total.

User avatar
barshatriplee
 
Posts: 200
Joined: Wed Mar 22, 2023 10:11 am

Re: Short Flex Sensor

Post by barshatriplee »

Since you are using a 3.3V board, 400 is normal I think. Because when connected to an Arduino UNO, the highest analog value is more than 900.

https://learn.adafruit.com/force-sensit ... ing-an-fsr

But 80 looks too much to be the lowest value. Because, when there is no external pressure, the value must be zero as far as I can see in the adafruit documentation. If it is possible, implement your circuit with an Arduino UNO or any other 5V Arduino. Thus, you can cross-check if the sensor is behaving as described in adafruit documentation.

User avatar
Bipman
 
Posts: 14
Joined: Wed Jan 11, 2023 6:29 pm

Re: Short Flex Sensor

Post by Bipman »

I've got one somewhere so I'll give it a go thanks.

Steve

User avatar
adafruit_support_mike
 
Posts: 67446
Joined: Thu Feb 11, 2010 2:51 pm

Re: Short Flex Sensor

Post by adafruit_support_mike »

Bipman wrote: Wed Mar 29, 2023 9:46 am I presume just changing the resistor will make no difference to the range,
That's incorrect.

The flex sensor is a variable resistor. Putting it in series with a fixed-value resistor gives you a voltage divider that makes the flex sensor's change in resistance visible. Using a lower fixed-value resistance makes the flex sensor span more of the voltage divider's range.

Locked
Please be positive and constructive with your questions and comments.

Return to “Wearables”