Add GPRS REST API to 8051

My existing Keil-C firmware for an AT89S52 (8051 core) already handles SMS and voice calls through a SIM800L module. The hardware set-up is fixed—4×4 keypad, 16×2 LCD, 24C16 EEPROM, plus the SIM800L on UART... (Budget: ₹1500 - ₹12500 INR, Jobs: API Integration, Arduino, C Programming, Electronics, Embedded Systems, HTTP, Microcontroller, REST API)