10cm FSLP demo problems

kracon7 · January 25, 2019, 11:42pm

Hi,
I was working on this 10cm fslp sensor with arduino mega2560 recently without cutting it.
I simply followed the schematic diagram from the tutorial:

and copy paste the code from:

github.com

pololu/fslp-led-strip-arduino-demo/blob/master/FslpLedStripDemo/FslpLedStripDemo.ino

/* FslpLedStripDemo: Example Arduino sketch that shows
 * how to use an Interlink force-sensing linear potentiometer
 * (FSLP) to control an Addressable RGB LED strip from Pololu.
 *
 * This code requires the PololuLedStrip library, which is
 * available from:
 *
 *   https://github.com/pololu/pololu-led-strip-arduino
 *
 * To use this code, you will need to plug an Addressable RGB LED
 * strip from Pololu into pin 12.
 *
 * You will need an additional resistor and four connections from
 * the FSLP to the Arduino.  The FSLP's integration guide from
 * Interlink can be used to make the correct connections as
 * follows:
 *
 * - Sense line (SL) to pin A2
 * - Drive line 1 (D1) to pin 8
 * - Drive line 1 (D2) to pin A3

This file has been truncated. show original

But it didn’t gave me the expected results. I take out the position-measuring part of the code and tested it alone. I set drive line 1 as output high and drive line 2 as output low, set both sense line and R0 bottom pin as ADC input. But the read out of sense line is always zero wherever I press it. Any idea why this is happening? Thanks in advance.

Here’s the wiring diagram which followed the schematic diagram from the tutorial I mentioned earlier.

Screenshot%20from%202019-01-25%2017-42-02

BrandonM · January 26, 2019, 1:39am

Hello.

I moved your post to its own thread since it seemed like a separate issue.

Thank you for posting pictures and a description of what you are doing. I do not see anything wrong with your connections. Where on the sensor are you pressing? If you have not modified the sensor in any way, only the first inch of the sensor will provide position readings. To get the full 4″ (10 cm) range of the strip, you must cut off the three small tabs along the edge. These tabs determine the active length of the strip, so only cut all three small tabs off if you want to use the full 4" length. See the “Customizing the strip length” section of the FSLP sensor’s product page for more information about this and how to cut it for other lengths.

If that does not fix the problem, can you send me an example of what the Serial Monitor is outputting when you run the unmodified example code and firmly press on the sensor (preferably along the length of the strip)?

Brandon

kracon7 · January 28, 2019, 7:57pm

Hi Brandon,
Thanks for your help. It turned out to be my fault to not going through all the dovumentation throughly. I didn’t cut the tabs according to the “customizing the strip length section”.

Now it works perfectly. Thank you so much.

Jiacheng