electronics

Building your own handheld GPS with an ESP32

With the inexpensive cost of electronic components online, I am amassing quite a library of modules and parts to build whatever little contraption my silly little brain dreams up. Lately I've been working on a portable GPS unit using an ESP32, with an off the shelf GPS module and 1" OLED screen. 

Quite often I'm in the woods and I know where I am, but I don't know where I want to go. Thus, navigating back home safely is important if I feel like simply walking into the forest alone. I wanted a simple GPS unit where I could calculate distances and display a map of my location, with beacons displaying waypoints and markers.

 

Over the last month or so, I have a fully-featured unit that can display the current longitude, latitude and latitude,  calculate distances between two points, displays a vector map, and a settings menu allowing the user to enter low power mode and change display settings. 

4000 series CMOS 24 hour clock

 For the last couple months a friend and I have been working on a 4000 series based clock in electronics class. After having failed building a FM receiver, we opted for a clock. We didn't go the microcontroller way, but old school ICs. So, we created a circuit for a simple clock. I opted for a 24-hour version, while my friend made the 12-hour equivalent. 

The above image was the basis of the circuit. Not shown was a 4060 and 4013 IC to make a nice 1Hz signal which we can use for the seconds. The rest is fairly simple: allow the seconds and minutes to count to 59 and use AND gates to reset at 60. Also pictured is the buttons to set the time. We used two 2N2222 transitors to make a NOT gate. Though, this ended up being too glitchy so I opted for a 4011 to create stable square wave.