Filament monitor for Arduino

Prototype is alive

The first prototype is running by about three days and after some revisions on the Arduino software (mostly on the calculation algorithms) it works fine, ready for the public.

The electronics

  • Arduino uno R3
  • 5kg max load sensor
  • Mx711 chip analog to digital sensor amplifier
  • A very small circuit with two buttons and a dip-switch
  • 16×2 alphanumeric LCD monochrome display
  • Orange LED (shows the load sensor readings when flashing)

That’s all

Arduino firmware

Easy to use

The Arduino script has been done to make the use of the tool while 3D printing; it works in a semi-automatic mode and does not need calibration or settings. One of the most interesting aspects is the ability to manage automatically the filament roll also if it is not on start. Then you can change it (e.g. changing the filament colour or material) and the system continue working.

What you should know

Before starting using the filament monitor you need to know the empty roll weight. This is the only fixed variables that can’t be calculated or deducted internally. Knowing this value is easy and you do not need to have an empty roll, obvious! If you weight on a digital scale (possibly one for kitchen more precise than a bigger one) you see that the 1Kg filament roll weight some more, e.g. 120 Gr. This is the weight of your roll that should be setup as the filament tare.

You should also know: Material (PLA or ABS are supported), filament diameter and full roll weight. These values should be preset through the three dip-switches as shown in the following table:

Meaning    Off     On
Material   PLA    ABS 
Diameter  1.75mm  3mm
Weight     1kg    2kg

How-to usage

  1. Power-on the support without the filament roll and wait for the display showing Started, The system is self-calibrated to the internal zero point.
  2. Put the filament roll on the rotating support and press the control button. Arduino calculates the effective weight,  deduct the filament tare and enter in the Ready state: remaining meters and percentage of filament as shown too
  3. Press the control button again; it enters in the Load state and you can start printing!

Pressing the second button you switch between grams and centimeters the constantly updated value of the consumed filament on the second line. The first line instead shows the remaining meters and the used percentage.

Note: as the length in centimeters reach the value 100 (1 meter) the displayed value is shown in meters instead.

 

 


Digital Potentiometer Arduino Shield Reviewed by Freetronics.com

Screen Shot 2015-03-24 at 07.50.40We wish to thank the friends of Freetronics (Australia) for the review of the Digital Potentiometer Arduino Shield on their great blog.

The shield PCB or full assembly version can be bought on Tindie. for 10$ (or less, follow the discounts and promotions). See the Freetronics full blog post here.

Digital Potentiometer Arduino Shield on Electro Schematics

Screen Shot 2015-03-16 at 17.54.02Full description of the Digital Potentiometer Arduino Shield on the new article on Electro Schematics electronic site. The article can be found in the Arduino section.

Includes downloadable sketches of the programs shown in the video below, a complete description of the project, schematics, PCB layout and the digital potentiometer device data-sheet.

The shield PCB or full assembly version can be bought on Tindie. Follow the full description on the product page.

Coming Soon MicroDrone project: MicroCamera arm test

The microcamera case should be connected to the microdrone arm support, the white component in the slideshow below. The two-parts arm-support has the advantage to be oriented and locked in different azimuth positions between 0 DEG (ground alignment) and about 60 DEG.

[st-gallery id=”5506e0d649d1f”]

Limitations

Microdrone test support (1200px) 3A well known limitation is that, due the very reduced size of the microdrone (about 14×14 cm) it is also reduced its payload weight so it is was excluded a priori any sort of automated camera movement control. Instead the stabilization of the video shooting is reached with rubber supports.

Another problem found during tests is setting the camera to the most vertical position (60-70 DEG). Due the unbalanced weight between the lenses body and the rest of the circuit when the camera is in a quasi-vertical position the drone tend to be unbalanced on the front side. This problem can be solved in two ways: adding a variable-length back queue to the drone body with the advantage of right balance and more stability or – a more complex solution – moving the camera second-half arm support almost in the same position of the lenses body.

Microdrone test support (1200px) 7The drone legs should be changed as the camera body increase the total drone height. A temporary solution, as shown in the images, has been found adopting commercial plastic hose clamps. These will be replaced by a carbon-fiber flexible and very lightweight part under construction.