Another thing I have been doing is learning to create android apps,  This turned to be fairly straight forward using an online application called thunkable.  I have created two apps to control the robot over Bluetooth, one for classic Bluetooth and one for Bluetooth Low Energy.  Both of these apps send a direction or stop variable back to the robot and receives and displays the current battery voltage with a battery low indicator displayed. 

Due to back pain I have not been doing very much to this project lately.  But what I have done is complete a knight rider scanner LED circuit running on 168 Arduino nano.  The code for this was cribbed from the internet. 

I also created a perfboard PCB to simplify connections so each of the boards can be simply plugged in.  This will make the whole thing a lot more modular.

 You may have noticed in the circuit below that I have added a Bluetooth module. I was also wondering if the weak motors were due to lack of current from the AA batteries so I have ordered a 7.4V lithium Polymer battery and charger.  I could use the Nano to monitor the battery voltage and even send this value over Bluetooth as well as indicating low battery voltage with a LED.

Another thought I had was adding a Knight rider type 8 led display to make it look like the robot was scanning. This would require a second Nano and/or a shift register circuit.  But this is after everything else is working.

The code I’m using for the balancing robot is based on a sketch that is all over the internet in various guises.  I can’t find any mention of the original author.  The version I am working on was part of a project by Aalto University in Helsinki. It is the only one that tried to use the encoders on the dc motors for additional stability.  I say tried because their project ultimately failed to produce a stable robot.  I can but try,  at least it’s a starting point.  The Aalto University project can be found here.

I have completed a circuit layout for the balancing robot. Not sure if the motors I bought are going to be up to the job due to lack of torque and slack in the gearbox.  We will see.