In order to use the BealgeBone Black as a flight computer or embedded system in a product, it must be able to launch programs we wrote on start up without having to manually start it after logging in via ssh. Something sweet and simple like an Arduino, when it start, it run the program you put on it. I spent days looking for ways to do this, editing init.d and all, none of them work. And finally, I came across this blog for Raspberry Pi and work perfectly!
So to be sure that the script is running without logging in through the computer, I decided to do a “blink” loop like what we do when we first started Arduino.
This is going to be a easy and fun one, analog joystick for Arduino. I got this one for around $6 from Adafruit. Awesome and easy to use. Essentially, this is what they use in all those consoles, PS1, PS2, PS3, PS4… Some stuffs you can make with this: robotic servo control, RC motor speed controller…
Last time I update this blog was almost a year ago… during this time, lots happened. I graduated from Lehigh University with a MechE degree, got 3 job offers. Got to choose 1, which is such a painful decision, but that will be for a later time. Long story short, I am back to Lehigh for a Master’s degree. For my thesis, I am building a “Guidance, Navigation and Control System for a Simulated Hopper Spacecraft”. Basically, building a tricopter / quadcopter to simulate the space hopper concept for space exploration. So I guess I will use this as my notebook again to document some work I’ve done, hopefully it will be easier when it’s time to write the paper.
So, ultrasonic sensor. A more expensive one, XL-MaxSonar.
Data acquisition is a very important part of test engineering. By plotting the data acquired in real time, we can analyze how the design behave and to determine whether it meet specs or not. Some examples of application are logging aircraft altitude and LiPo battery cells temperature. In my previous project of designing an aircraft altitude controller, the real time data logger is a key part of the project in determining how the system perform. In that project, I used Java to program a real time data plotter and it was such a pain. The code became so messy that I do not want to look at it ever again. It took such a long time too.
So this time, I turned to MATLAB. As a 4th generation programming language, this is so much easier since it got a Serial interface and plotting function built in. In the end of this post, we should get sometime like this:
This is a simple project that I did with the LCD Shield to learn how to use it. Basically, you can use the buttons to scroll through the different pins and control the lcd display back light. Basically, this is a mini voltmeter. Good for testing out raw sensor readings.
In this post, we will explore an easy method for transferring data from one Arduino board to another using Bill Porter’s EasyTransfer Library. Here’s a traditional method on how you hook up Arduino’s serial ports. TX to RX, RX to TX, Ground to Ground. TX is the transfer pin and RX is the receiver pin, therefore you connect the one to the other. Finally, in order for the two device to communicate with each other, the two boards must have a common ground. Here’s the wiring I drew using Fritzing, I figured it’s probably time to be neater in describing how to hook stuffs up, lol.
Time to open up the new toys I got from China, DFRobot LCD Keypad Shield (DFR0009)! As I said, I ordered this from China’s ebay equivalent, Taobao.com, got this for 30 RMB ($5 USD), pretty cheap for a LCD display panel, let alone this is a shield with keypad! In the US, it is being sold for $15!!! Anyway, the link is follow if anyone is interested. Maybe I will do a post about ordering stuffs directly from China. I spent like $50 total and stocked up my electronic inventory with all kinda of new shields, joysticks…