Orientation sensor (and actuator)

[AWI]

With the latest additions in sensor type e.g. the position/ GPS sensor there was still something missing. Orientation sensors are popular in e.g. flight control and mobile phones. For a proof of concept I ordered a MPU 9250 which consists of a Gyroscope/ Accelerometer/ Magnetometer (compass) and BMP280 - barometer/ temperature.

This is an advanced device which makes it possible to determine the exact orientation/ movement and altitude.. Mounted to @GertSanders "Battery based atmega328p sensor" this makes a perfect "Orientation sensor" with a simple I2C interface.

For the purpose of demonstration there is an actuator which is basically a pan/tilt servo construction pre-built with 2 servo's and a little plastic.

Next (hard to find) thing was an Arduino library to read the sensor an create acceptable position readings. In flight terms these are named:

Yaw - for the orientation in the vertical plane
Pitch - orientation in the horizontal plane
Roll - the position of the object (e.g. aircraft) around its own axis. (not used in the example)

As there (currently) is no "Orientation type" for MySensors I have created my own type as a subset from the V_TEXT type.
V_ORIENTATION = Yaw ; Pitch ; Roll

A (working) library was found in the "Modern devices - motion plug" example.

The video should give you an idea of the current setup and workings. All through the MySensors network. I will upload the details on Openhardware.io if I can get the hang of it.

MySensors - Orientation sensor Demo

[hek]

Nice to someone play around with a 10DOF device. And I like the video!

[Fat Fly]

Can to drive with mpu9250 solar panels ? Solar tracker by sun position coordinates ?

[tbowmo]

That looks awesome. Think I have to try something like that as well

[Fat Fly]

MPU 6250 works too. But how to drive linear actuators and how to set and from where get coordinates? Oh. Too many questions.

[AWI]

@Fat-Fly a sun panel tracker based on this circuit is in place on my roof. My major issue is mechanical. How to seal the (stepper) motors from the environment.

[koen01]

@AWI said:

@Fat-Fly a sun panel tracker based on this circuit is in place on my roof. My major issue is mechanical. How to seal the (stepper) motors from the environment.

I once saw someone on YouTube that mounted them in pvc pipe with a cap.
He used electric drill motors for the actuators though.

How to build a solar tracker. DIY solar panel sun tracker. – 14:20
— Aceman307

[Fat Fly]

How to this sensor knows where is the sun?

[koen01]

@Fat-Fly said:

How to this sensor knows where is the sun?

I guess 4 ldrs with a cross between ?

[Fat Fly]

Okay. But why for this mpu9250? These ldr's not working correctly if cloudy. Turn with sun coordinates is possible but i do not find cheap system. Raspberry PI and with arduino + mpu9250 or 6250 + linear actuators.

[AWI]

@Fat-Fly the position of the sun is very predictable . I use a simplified algorithm to calculate where it will come from. So no DOF sensor needed here only the actuator.

[Fat Fly]

Solar tracker first test. – 00:21
— Ants Kosmos

[Fat Fly]

How to drive this ?

[koen01]

@AWI
Is it possible to sleep the node and wake it up by external interrupt ?
I have a use case for this but it has to be battery powered.

[AWI]

@koen01 I assume you are refering to the orientation sensor.. You can sleep the node and have it wake up by external or internal (timer) interrupt. Power consumption when powered down is minimal. Look at API for "Sleeping". I am using a setup with solar power for a wind/weather station (on-going development ..)

[koen01]

@AWI
Thank you for answer.
See this link for an project based in this.
Its basically a scène controller in the shape of a cube.
I got the idea from the original poster in the thread over at home-assistant.

https://community.home-assistant.io/t/rubiks-mood-cube-magic-cube/9965/8

I will post a BOM, sketch and pics if someone wants me to.

[koen01]

@AWI
This is how it looks like at the moment.
Still taped together as everything is beta stage.

Mysensors 3-axis remote control. – 00:26
— koenerens

[koen01]

Some more info on the cube can be found at the homeassistant forums
https://community.home-assistant.io/t/rubiks-mood-cube-magic-cube/9965/11?u=koen01

[hek]

@koen01, really like this cool cube project.

Couldn't you add it as a new project on openhardware.io? This enables me to show it on the mysensors.org build pages as well.