Converting a $20 4G wireless hotspot into a texting device

This story details the process of transforming a $20 4G wireless hotspot into a texting device. The author, who tends to be disorganized, began with a pile of components on their desk. They discovered a 4G modem with WiFi, Bluetooth, a display, and a battery for under $20, which became the foundation of their project.

The 4G hotspot supports Linux, which the author installed using the openstick project. The device is initially running Android, but developers can easily access the device's bootloader using adb. This allows for flashing new firmware and reconfiguring the device as needed.

The project also involved a Clicks Keyboard, which the author found to be of high quality, despite the need to fork over a significant amount of money for it. The keyboard operates like a regular USB keyboard, with an additional Apple proprietary endpoint for authorization.

The author opted to create a custom PCB to accommodate the USB host mode power, USB host/device mode switching, display power, and signal level conversion. They faced challenges with fitting all the components on one side of the PCB due to size constraints and the need to chop off the USB connector.

Once the custom PCB was assembled, the device booted up successfully. The author confirmed that there were no crucial lines on the PCB that would interfere with their modifications. They also discovered that the USB connection and 4G modem were unlikely issues, as they did not interfere with the areas of the PCB being modified.

In summary, the $20 4G hotspot was converted into a texting device by installing Linux, creating a custom PCB to handle power, display, and USB connections, and utilizing a high-quality Clicks Keyboard.