Fuzzy Robot / Flex Sensor

[amyCC]

[Posted on behalf of student]

I am doing the build a fuzzy companion robot project. I have followed the instructions carefully and copied the code from the tinker-cad vibration motor and flex sensor simulation and pasted it in my Arduino app. However, when I verify the code and press the arrow button, as a result of bending the flex sensor, and doing so various different ways, the vibration motor does not vibrate at all. Please advise on how I should solve this problem. Additionally, how do you probably solder wires to the screw terminal? Thank you in advance.

[amyCC]

There is some information about the soldering in the project materials list. SparkFun has a guide about how to connect the sensors: https://learn.sparkfun.com/tutorials/fl ... -guide/all.

They do not recommend soldering because the heat can damage the sensors.

There are a number of methods suggested in that article, but the project uses the screw terminals that are linked in the materials list.

We are reviewing images from the student to troubleshoot the sensor.

Amy
Science Buddies

[bfinio]

Hi,

I am posting this reply based on pictures of the student's circuit. There are a couple issues:

- Your MOSFET is in the breadboard backwards. The large metal tab should face to the left, and the writing on the front should face to the right.
- You have the 5V and GND wires from the Arduino to the breadboard reversed. 5V (the orange wire you have plugged into the Arduino) should go to the positive bus (the red one with the "+" next to it). GND (the green wire) should go to the negative bus (the blue one with the "-" next to it).
- I cannot tell for sure because the MOSFET is partially blocking the view, but it looks like the blue wire coming from the Arduino and the white wire going to the motor might be in the same row of the breadboard. They need to be in two different rows so they are connected to different pins of the MOSFET. Please double check Figure 2 in the project procedure.

Also note that you can confirm that your sensor is working by looking at the output in the serial monitor (Tools->Serial monitor). You should see that number change when you bend the sensor, even if the motor isn't working. If you see the number change, that means the problem is with the motor. If the number does not change at all, then there is also a problem with how the sensor is connected.

[amyCC]

[Posted on behalf of student]

I just got my vibration motor working, however it is now vibrating nonstop and now the flex sensor is not changing numbers on the serial monitor when I bend it. [I have sent photos.] Please advise on what I should do next. Thank you in advance.

[amyCC]

Our team reviewed your photos and video.

1. The motor is vibrating nonstop because the white and black wires are in the same row (based on the photos you sent). All three wires (blue, white, black) need to be in different rows. In your current circuit, leave the blue and white wires where they are and move the black wire up one row. (I've attached a screenshot of relevant part of circuit diagram from the project, but please note that the colors are different. Don't let that confuse you. This shows you how they need to be on different rows.)

2. The flex sensor is no longer working because the red wire is no longer in the same row as the resistor, so they are not connected. (It looks like you changed this from your previous circuit.) To correct this, move the red wire down to row 23 (based on the photo you sent us) OR move the end of the resistor up to row 22.

We would recommend that you stop and watch this breadboard tutorial video, too.
https://www.sciencebuddies.org/science- ... breadboard It will help explain some things that will help you troubleshoot these kinds of issues as you work on your project.

Amy
Science Buddies

[amyCC]

[Posted on behalf of student]

When I am not doing anything, the vibration motor is vibrating off and on. However, when I bend the flex sensor and touch it, the vibration motor doesn’t change, and continues vibrations on and off. Finally, the numbers stay zero in the serial monitor when I bend the flex sensor. P