Axoloti and sensors

#61

hi there,
i’m working on art installation. I connected an accelerometer and ultra sonic distance sensor to my axoloti and i need some help.
First of all i would like to read 3 axes information for the accelerometer and distance parameter for the distance sensor.
Thank you !

#62

For an ultrasonic sensor, you might need program a custom object since those sensor send out a digital signal. It's easier to work with an infrared sensor like this one: https://www.amazon.com/GP2Y0A21YK0F-GP2Y0A21-Infrared-Proximity-Distance/dp/B075FPR2VX?SubscriptionId=AKIAILSHYYTFIVPWUY6Q&tag=duckduckgo-d-20&linkCode=xm2&camp=2025&creative=165953&creativeASIN=B075FPR2VX

Accellerometers can be connected like in this breadboard setup: http://www.axoloti.com/examples/general-input-and-output/. The incoming values will be positive only (0-3.3V), so you might need to convert them to a bipolar signal using the conv/unipolar2bipolar object.

#63

hi, thanks for you answer
For the ultrason sensor it's a binary signal but the time of the trig move proportionaly to the distance so i think it's possible to sampling this value (trig time) ?
Our accelerometer send SPI, i think i'm going to buy accelerometer with analogique output, if can't do in other way ?
Thanksss

#64

You can indeed sample the incoming binary signal, but you'll need to convert the data to something that will make sense. That's why you will need a custom programmed object.

Reading the data of the accelerometer over SPI is possible, but you'll also need a custom object for that.

#65

Hi there!
I was wondering if anybody has experience with following interesting module:

MPU-9250, contains a 3-axis gyroscope as well as a 3-axis accelerometer, and the AK8963, which features a 3-axis magnetometer and also outputs ambient temperatures.

amazon link

All of my axos for now are portable in the sense I can walk around with them. The magnetometer would allow me to for instance: guide me in north direction during my walking/music/trips, modulating sound when taking turns etc.. Plenty of nice interaction ideas... I love the idea of improvisation and interaction with the environment, especially when one has 'no' other choice than for example following the road letting the circumstances become part of the music.

Since it has i2c and SPI I could chain it with, for instance, my OLED.

I have no coding talent, but adapting things lies in my possibilities.
Does anybody have a clue whether this would be feasible and maybe prepared to guide me in the right direction?

Have a nice day!

EDIT: I should note that I m currently using the MPR121 capactive modules on one of my axo's. Maybe I could adapt the code of this module made by @deadsy for this purpose?

#67

definetely possible but you'd need to write your own objects to drive the chip. depending on our project it might be easier to use a teensy/arduino to control this chip since there likely are libraries available for these platforms. and then send midi to axoloti.

#68

Hi Weasel,

tnx for your reply. I took the time to let it sink a bit.
Writing my own objects is a little bit above my head I think. I have investigated the teensy path a bit and must say it sounds doable (price-wise and skill-wise) for me. Code is available I think. Exploring teensy would open up some more possibilities for me.

On the other hand I like the 'simplicity' of doing everything on one platform.
hmm, I'll let it sink a bit more and probably keep the idea for a future project when I get hold of another Axoloti Core when they become available.

Thanks for clearing things out!

#69

Hi,

I am conecting a IR sensor (GP2D12) but I am getting a annoying hiss noise when it is connected. If I remove it then it stops.

Has this happened to someone else, and what is most important, iIs it possible to solve it?

Thanks

#70

I heve benn making different tests and finally I found out that this hiss noise came from Axoloti beeing powered by computer USB bus. Using an external power supply it dissapear. I hope this can help someone else.

Best

#71

that sensor being 5v maybe it has something to do with the hiss too..

#72

Thanks @servandisco. It could be. I guess it is also problem with USB cable. Now I am using an isolated audio conector and it is less noisy.