Show HN: Hacking a $20 4G wireless hotspot into a texting device

A user, going by the handle 'bkovac', has successfully modified a $20 4G wireless hotspot, specifically the ZTE MF823, into a device that can send text messages. The modifications involve replacing the device's original firmware and adding a small microcontroller to handle serial communication. This allows the user to send and receive SMS messages using the device's 4G connectivity. The process of modification is outlined in a detailed guide on the author's GitHub page, including the necessary hardware and software components, step-by-step instructions, and code examples. The author notes that the device's original purpose was for internet access, but the modified device can be used as a dedicated SMS sender or receiver, potentially useful for IoT applications or other use cases where a dedicated text messaging device is needed.