Some time ago I bought a Raspberry Pi 3B with the RPI-RF-MOD extension module and the corresponding case. It’s also possible to buy all in a set: Buy link (I am not affiliated). There is an image available that works like a charm for this setup, whcih can be found here. Multiple models are supported, so make sure you download the correct release.
I am very happy with this setup. HomeMatic provides a multitude of different devices ranging from simple sensors (temperature, light, …) to quite sophisticated weather stations. There are also actuators available for heating control, blinds/shutters to alarm sirens. What is even more interetting is that general relays and comunication modules are available, so you can also build your own smart home devices!
Continue reading RaspMatic + HomeMatic (IP)
I just spent at least two hours trying to figure out how to get the Arduino Pro Micro running again. I will spare you the details of how I figured out what to do, so here is the solution:
sudo mv /usr/share/dbus-1/system-services/org.freedesktop.ModemManager.service /usr/share/dbus-1/system-services/org.freedesktop.ModemManager.service.disabled
Lets hope it keeps on working 🙂
in a previous post I briefly showed how to read the sum signal of a receiver that is able to output the signal. Although the code works quite well there are several issues with the code:
pulseIn(SignalPin, HIGH) blocks until the corresponding pin is set to
HIGH, which is a major waste of time, because no other calculations can be performed in the meantime
- I noticed that every now and then the readings start to glitch causing unwanted noise
To cope with the first issue I used Arduino’s external interrupt feature that calls a callback function for every rising edge. In addition I wrapped it in a class and defined it as a library for easy usage.
[update: 2013-07-28][update: 2013-08-02]
Continue reading Reading RC Receiver values (version 2)
Some time ago I wrote something about getting a cheap GPS receiver, a cheap AHRS, and how to read values from a RC receiver. All those tools can be put together to control an autonomous vehicle of some sorts. If the vehicle is a small ground robot nothing more is needed, except the vehicle itself, of course.I do not own anything that is capable of driving around outdoors, but I do own a small airplane. Continue reading Pitot tube
I recently bought an e-paper display with a 2.7″ screen size distributed by Embedded Artists. Since it does not consume any power between updates it is perfect to display status information for any kind of embedded technology. Since I am quite the Arduino fan my plan was to hook it up to one of them and simply use an existing software library to interface it. (Update available)(second Update)
Continue reading e-paper display
Using a RC transmitter to be able to control aspects of a circuit controlled by an Arduino is a very nice feature. The first thing that comes to my mind is controlling stepper motors instead of servos, as they are way more precise. An easier example, but cool nonetheless, is mapping the input to a PWM signal for diming LEDs.
Reading the values of the channels of your RC receiver is not as complicated as I first thought.
That is, if you have a receiver that is able to output a PPM sumsignal.
I recently bought a RC set, the mx-10 of the HoTT series from Graupner.
The receiver GR-12 coming along with it is able to provide you with up to 16 channels! However, the mx-10 has 5 channels, so setting it to a higher value makes no sense in this case.
Continue reading Reading RC Receiver values
some time ago I bought an Inertial Measurement Unit (IMU), to be precise I bought the MinIMU-9 developed by Pololu. (The link in case you need it) It’s small, cheap and provides gyro, accelerometer and compass readings, each in 3D. It is perfect for implementing an Attitude and Heading Reference System (AHRS), very important if you want to control a RC plane, drone or other robots.
Luckyly, Pololu provides a complete software suite for the arduino, including the libraries for each sensor as well as a sample implementation for a AHRS, based on a Direction Cosine Matrix (DCM) approach. As I have close to no understanding of the theory behind this, I am very happy that the algorithm prints the roll, pitch, yaw angles to the serial interface ready for me to use!
No drifts, little noise (I need to take a close look there), simple as that!
for my first post that actually contains content, I would like to show you what I use as a cheap and small GPS device.
GPS devices can be found in a lot of different devices, like mobile phones, cars and security devices. One class of such security devices are GPS -Tracker. GPS-Tracker constantly register their position and send the information to a previously specified user via eMail or SMS. I bought this tracker (for ~60€) that sends a SMS with the current position as a reply to a request SMS coming from me. The initial idea was to get the position of a RC plane in case its lost or to track the position of my cat 🙂
Continue reading Small and cheap GPS