Monday, February 29, 2016


I have been experimenting with techBasic for the iOS environment. It has it's ups and downs but is very comprehensive and well documented. It is the most expensive app I have ever purchased however the price is cheap considering what your getting. All the development is done on the device, e.g iPhone or iPad, I ended up getting a Bluetooth keyboard for my iPad, but it is cool coding on your iPhone directly.

Using the examples I was able to create an app that sets two dim levels over WiFi using UDP to a simple server running on my PC. There is a lot of potential and this barely scratches the surface of what techBasic can do.

Sunday, February 14, 2016

Teensy 3.1 DSP Functions

I was inspired by this recent SolderSmoke Blog post --> ZL2CTM Teensy SDR about using a Teensy Microcontroller as a software Intermediate Frequency (IF) stage for a direct conversion receiver.

I had seen some of the DSP capabilities of the Teensy and have done some simple tone generation test but that is it. I noticed that the PJRC site has been updated HERE and there is a very nice Audio Tutorial that I watched and enjoyed.

Just to start out, and to look at the filter capabilities, I used the web-based Audio Design Tool on the PJRC site to create the following:

This is just to have two Audio Sine-wave sources and a noise source in an attempt to experiment with the Biquad filter. I then take the output of the teensy audio shield and feed it into a PC with a audio spectrum analyzer to see the shape of the filtering. So far I have not built a sharp skirt filter but it is possible per Charlie ZL2CTM.

When I get more time I would like to duplicate Charlie's results using my NE612/Si5351 DC receiver.

Sunday, February 7, 2016

Folding Camper Design II

I continue to work on the initial design of the folding camper using SketchUp. Have not bought any wood yet but very close.

I came across a folding camper design that has given me many ideas for my above design and helped with some decisions. I could only find bits and pieces of it online. It was from the Popular Mechanics issue from May 1964.

For whatever reason Google Books did not have that issue available scanned. I did find a copy on ebay and scanned the pictures and OCR'd the texted of the article for further reference  HERE --> Inspiration for Camper Design