Arduino

Playing with Arduino

I’ve been busy playing with Arduinos these past few months. I think I must have been locked in a cave the past 8 years or so. I’ve been shocked by how advanced and inexpensive these things have become. These things are awesome, and very inexpensive. I plan on installing a dozen or so throughout my RV to control just about everything. Couple that with my iPhone programming skills, HomeKit, Siri, and the new Amazon Echo, and this is going to be a high tech playground for me. Woohoo!

I had been struggling with getting nRF24+ radios working, to provide cheap communication between Arduinos. It turns out that a bunch of folks at MySensors have already implemented a very cool, open source solution along the same lines. This is an incredible site. The information there really helped me get my radios working. They’ve done a lot of good work to provide clear instructions on how to connect multiple Arduinos together using open source software. These Arduinos can then read various types of sensors in order to control all sorts of things. I feel like a kid in a candy store (“ooh, which one do I want next?”). The crazy part is the price of these parts. They have a really well done page listing out links to buy all the various parts at unbelievable prices. Thank you MySensors!

Unfortunately, I think I’ve let myself become spread too thin across exploring and playing with all these cool technologies. I’ve written an iPhone app and Apple Watch extension that uses the Lightblue Bean to display the level of the RV remotely. I got it working well enough to use for myself, but I haven’t taken the final steps to post it to the App Store so that others can use it also. It’s very close to being in a state that can be released to the app store, but I’d rather play with new Arduino projects instead of spending the time to finish and submit it. I’ve also setup several Arduinos to control fans and lights in the RV, but they’re still sitting on the workbench. I’m trying to get them connected to the internet so the Echo and iPhone can control them.

So now I’m going to try to be disciplined with myself, and focus on getting a few basic pieces done and installed before worrying about adding more advanced features. With the 3 day weekend coming up, I’m hoping to get the Lightblue Bean installed in my closet to control a string of led lights based on sliding door microswitches, and an Arduino Uno hooked up to control dimming some LED recessed spotlights that I installe over my booth workbench. I’ll post back later about how that goes.

RV Automation using LightBlue Bean

I’ve started playing with the LightBlue Bean as a part of my RV Automation project. This $30 part combines a low power, 3.3v Arduino board with Bluetooth LE, several sensors, and an attached 3.3v watch battery. This means that it can be used to do a lot of jobs without any connections whatsoever, and it can talk with an iPhone over BTLE.

I first heard about this part from a github article that my friend Sean wrote. It’s a well written article, fun to read, and I recommend that you read it. Thank you, Sean.

What Can I Do With A LightBlue Bean?

Using Bluetooth

I think the best thing about this part is the built-in blue tooth.

iPhone Connection

I expect the bean to be a bridge from my iPhone to other Arduinos. BTLE makes it very simple to interface to an iOS device using

iBeacon

I may be able to take advantage of the fact that any BTLE device can be configured to act as an iBeacon. This will enable the iPhone app to determine proximity to it. This leads to all sort of automation possibilities:

  • Turning nearby lights on/off
  • Disabling security system when near
  • Unlocking doors

Of course, security will be important, so I’ll have to consider carefully the use of a passcode or some other system to prevent allowing unwanted access if my phone is stolen.

Using the built-in 3 axis accelerometer

The bean also includes a built-in 3 axis accelerometer. This means that it can detect motion in any direction.

Security System

One of the shortcomings of living in an RV is that it moves when walking around inside of it. I’m planning on turning this into an advantage, and use this as a component of my security system.

Leveling

The accelerometer will be used to help me level the RV when parking. Since gravity is indistinguishable from acceleration, it makes a great way to check for level. I’ll need a way to calibrate the level settings after mounting the bean, and I’ll want to convert the accelerator readings from Gs to angle for display on my iPhone.

Door Motion

Another possible application, but one I don’t plan on using at this time, would be to mount the bean to a door. Since it’s battery operated, this could be as simple as just sticking it onto a door.

Using the Temperature Sensor

This is a no-brainer, but does require me to think about where I mount it. Do I want interior or exterior temperature readings?

Using the RBG LED

Status Display

I expect to mount the LED such that it can be used for displaying status of some sort. It can display any color, and be dimmed and/or blinked, allowing for a large range of indications.

Interfacing with Other Arduinos

I expect the bean to be a bridge from my iPhone to other Arduinos using inexpensive RF24 parts. These can be purchased for under $2 each.

Replacing the Battery

I expect to connect it to my RVs 12v system eventually, so I don’t have to keep replacing batteries. This will require a 3.3v regulator. The LD1117v33 is available from Amazon for under $2.