FUTURE

Really great to be able to measure ionizing radiation but the Geiger counter module is pretty large and unwieldy. Will look into possibly designing my own Geiger-Müller tube with a far smaller size. 

Some things I want to test with the SDR:

1. Designing a flat antenna: Right now it has a "normal" stick-like antenna used for TVDB signals. This is fine except it sticks out of the device, making the overall size larger. Will check if it is possible to design a "flat" antenna like the ones found on smartphones or on the rear windows of cars. Currently don't know anything about antenna design but I'm looking forward to tinkering with it.
2. USB connectivity: Currently uses a USB port to send/receive data. As a result it has to be plugged into the Pi instead of being connected to the microcontroller. Might require an FPGA. 
3. Sensing range: Current model is quite basic and measures only up to ~1.7GHz. Would like to find a good balance of range and weight for an SDR. The really good ones (such as HackRFOne) are currently large and power hungry.

One of the biggest challenges with the current design is the acquisition of a video feed by only using the tricorder. The camera is used for a few different functions but I was hoping to find a solution that works with microcontrollers instead of using an SBC like the Pi. Currently, I magnetically attach and detach the camera from a designated space on the sensor module's PCB. This or this might be a possible solution.

Currently this is the single largest and single most expensive component in the entire build. In fact, I had to design the PCBs around this critical piece so as to minimize total volume. However, being able to measure distances (and speed) up to 40m is a really incredible feature. Since I already have an IMU and optical camera, the LiDAR can be used to make 3D maps of places. 

Discovered some SBC design tools such as build root and yocto. This might be a good exercise but I haven't attempted it before. However, I have programmed FPGA boards so that may be one option to increase speed of sensing and visualization.  

The next logical step to hardware miniaturization would be using Surface Mount Devices (SMDs) instead of Through-Hole Devices. With SMDs, the scope for miniaturization is considerable but it will require purchase of more sophisticated equipment and dedicated lab space, which I currently don't have this in my student apartment.  

PCBs with more layers may possibly be required. Currently utilized Fritzing for PCB design but I am shifting to KiCAD since Fritzing only allows up to two layers of connections. 

Currently in the process of learning CAD (Fusion360) and 3D-printing related skills so I can make functional prints.