In the age of COVID-19, it's more important than ever to maintain your distance from others, but what about people who have to take care of others? Two makers, Niccolo Avogaro and Edoardo Palladin, teamed up to build Pepsi, which is a web-controlled rover that is meant to transport supplies to infected people without any risk to those who are healthy.
This rover uses a balenaFin to communicate over the web via 4G cellular, which means it can be used independently of WiFi, such as in an open public space. It has a large sheet metal top that can hold equipment and supplies, along with a strong chassis to support the weight.
The primary component is a Raspberry Pi Zero, which when used in conjunction with a balenaFin and Pi Camera, lets users control the rover remotely. Next, there are two 12V batteries and a single 24V DC motor that are driven with two L298 Dual H-Bridge motor drivers. The chassis is composed of generic aluminum tubes and angle bars, along with four wheels.
The team's project is documented wonderfully through its ample number of pictures. They began by creating the rover's chassis with metal tubing and covered it with a large piece of sheet metal. Next, the team attached the wheels and battery, along with a motor and drive circuit. The RaspiCam is mounted on a two-axis gimbal that can rotate.
For the "brain" of the rover, the creators of this project began by downloading Raspbian OS and writing it onto an SD card. Next, they installed Flask, Adafruit's PCA9685 library, and finally a RaspiCam livestreaming service.
The balenaFin can be set up in a similar way, but it also supports 4G cellular with a nano SIM card.
The Pi runs a webserver via the Python library Flask that serves a webpage and allows for the rover to be remotely controlled. The two motors are controlled by a pair of virtual joysticks that get their values mapped with a MATLAB program. The servos are controlled with simple sliders.
This project is an amazing demonstration of how powerful 4G connectivity can be, especially in a project that is able to help others. Be sure to go and view Avogaro and Palladin's write-up, as it gives an intricate level of detail.