Securing gimbal to RC car
This is our station we created from our own supplies
charging the custom batteries we soldered together. Took batteries from old laptops.
Measuring lengths for supports we need to model and print
Assembling the gimbal
Attaching supports to gimbal
Setting up the GPS and cellular communtication
Designing the gimbal
3D printing a gimbal ring
Inspiration for 3D PRINTED GIMBAL, GPS, CELLULAR, Robot and Synth
Our team had too many ideas going into Citrushacks. Because of our drive and motivation to make the best of the weekend, we decided to build two projects.
Using a broken RC car as inspiration, we wanted to build a robot out of the platform. We challenged ourselves to build a gimbal platform that remained stable without using external actuators or motors, but only through physical mechanics. We were also inspired by the sheer number of parts we assembled. We decided to build an analog circuit to make use of all the transistors, ICs, and resistors we had. We figured that an amazing way to showcase analog oscillations would be with a electronic music synthesizer.
What it does
We called our robot the beverage buddy. It delivers beverages to the user without spilling it by using a gimbal platform to keep it upright. This gimbal is not powered by accelerometers or motors, and remains upright by taking advantage of angular momentum properties (in a special enclosure we designed!) While traveling, the robot updates the user with GPS tracking updates through SMS text messages so that you can rest assured your drink arrives safely and quickly.
How we built it
We had to computer model, design, and 3D print the entire gimbal assembly. Furthermore, we had to code protocols to communicate with RC, GPS, and SMS texting at the same time.
For the synthesizer, we utilized a 555 timer chip in sequence with a capacitor and a resistor to create an oscillator circuit. This oscillator was then routed and sequenced into other oscillator to create interesting sound waveforms similar to an old atari console (8 bit sounds). We then passed the signal through a multiplexer and bit shift register to create a sequencer.
A sequencer stores sound data into an array, which can then be played back by the user, creating a melody.
Challenges we ran into
Analog circuitry was very difficult because each pin of the microcnotroller was used up, and each pin required at least 2-3 wires. This means we had to solder almost 50 wires!
We also had no battery for the RC chassis, so we had to rig our own battery pack together using old laptop batteries. We had to do lots of calculations to make sure we didn't blow anything up!
Accomplishments that we're proud of
1) Designing and manufacturing the entire gimbal assembly using solidworks, Cura, Pronterface, and a 3D Printing. It is very difficult to print parts that have correct dimensions. Furthermore, each part takes at least 5 hours to print. Because the hackathon was only 24 hours long, we did not have room to make mistakes because then we wouldn't finish printing all the parts in time!
We took extreme care to measure and assess each dimension so that the parts would mesh perfectly.
2) Machining and drilling a enclosure box for the synthesizer that utilizes knobs, buttons, and LED array to display 8-step sequencing.
What we learned
We learned how to implement GPS and Cellular devices for the first time. We were able to sync our robot with passing GPS satellites, which beamed location coordinates to us through SMS (through our own homebrew protocol).