This is just for your information if you are a Raspberry Pi user and playing with Python code from my blog. If you are trying to use the latest distro of raspbian with pyserial for some serial port project, you may have come across this issue that regardless how you upgrade pyserial using pip3, your python3 will always call up the old pyserial 2.6 that came with the distribution. I am a bit disappointed that the foundation has included such an old version of pyserial, couldn’t they just try a pyserial 3.0 instead? My solution was to remove the python3-serial module using apt-get and then install pyserial 3.3 using pip3.
I have been involved in constructing augmented reality sand box (ARSandbox) lately. It is a beautiful project created by Dr. Oliver Kreylos at UC Davis. The system uses a Microsoft XBox 360 Kinect sensor to digitize the sand in a box and then uses a projector to project color-coded elevation and contours on the sand, thus augmenting the sand with colors and contours. Here is a photo I took on a prototype that we replicated from the ARSandbox created by Dr. Kreylos:
When someone manipulates the sand, thus changing the topography, the projected colors and contours change accordingly. You can also rain over the terrain by a hand gesture over the terrain.
For those that didn’t know, the Microsoft XBox 360 Kinect sensor is a sophiscated set of sensors that include IR projector and camera for depth sensing, body movement and gesture capture, and regular RGB camera and microphone array. The software Dr. Kreylos developed takes the depth image and calculates a topography map and projects it onto the very same sand using a calibrated projector. To show you how good the simulation is, here is a photo:
Did you notice the white cone and the colors/contours on it? The contours are depicting 1cm heights and the cone is about 4cm tall. Here is a close-up of the cone placed at a different location:
It shows roughly 4cm tall and the contours are very well centered around the tip of the cone.
Here is a video:
Like it? The whole setup is not cheap. It needs an expensive video card for the simulation, especially the water. It also needs a decent desktop computer and projector, sand box, frames etc. Here is what my setup looks like:
I didn’t buy a more expensive (thus shorter throw ratio) projector so my setup is very tall even without any legs. I am hoping to develop it into a portable system so I can take a few of them to teachers’ training workshops, museums, schools, fairs etc. for basic education and outreach for water resources.
What I’m thinking about doing using my Arduino/Raspberry pi skills is to add sensors to help preserve the projector’s bulb and have kids and operators interact with the sand box without having to use the keyboard and mouse or understanding linux. Big buttons will do certain predefined things such as rain, drought, etc.
After a final revision, I am happy to release the SDI-12 GPS USB adapter! This adapter is the latest one to add to the line of SDI-12 USB adapters. In August 2015, I released my first SDI-12 USB adapter with this post. It was an idea that I thought about while traveling. I was working on data logger designs that use SDI-12 sensors and felt that interacting with SDI-12 sensors is not easy for agricultural or water resource researchers. Having an adapter that connects a computer to an SDI-12 sensor and reads measurements directly from the sensor would be very useful. So I made the adapter to simplify lab tests and data logger deployments. Since then, I’ve written free Python scripts for basic data logging (read the SDI-12 USB adapter main page). The demand for the adapter since then has been high enough to support my continued update on the data logging script, expanding from PC/Mac/Linux to single-board computers such as Raspberry Pi and Beagle Bone Bone. I have also expanded the adapter with an SDI-12 + Analog USB adapter that includes four high-precision analog inputs.
Later I found some need to add GPS modules to the existing SDI-12 USB adapter so that mobile data loggers such as those mounted on tractors will be able to produce with Geo-tagged data that can be made into maps. After some initial struggle using the new ATMEGA328PB processor that sports two hardware serial ports (one to talk to PC and the other with GPS), I realized that the GPS module actually interfered with the processor and caused program freeze-up. Then I made some hardware revisions and was able to prevent interference. It turned out that the new ATMEGA328PB processor that I used in my initial prototype was especially susceptible to interference when I used its second hardware serial port that have the same pins as the SPI pins that program the processor. So I switched to the ATMEGA1284P processor that I have been using on my open source physics laboratory design.
After extensive tests, I am happy to add this adapter to the product line. You can purchase (small quantity at the moment) at inmojo.com or on my blog (in the middle of the page). The adapter requires a separate purchase of the GPS module that Adafruit makes and sells, the Ultimate GPS module part number 746. You only need to solder four pins on the GPS module, the TX, RX, GND, and VIN, and the same pins on the adapter. Since the GPS module is relatively expensive, I can’t stock them up. But if you really need it assembled, you may have a GPS unit sent to me and a few extra dollars for assembly and testing. Just contact me once you make a purchase if you want assembly.
