This post will be shown how to connect the Sixfab GPRS shield with the Asus Tinker board.
The advantage of using Asus Tinker instead of Raspberry Pi is the number of UARTs. In the Asus board, there are 4 UARTs while in the Raspberry Pi there is only 1. As Sixfab GPRS shield uses UART to communicate, in the ASUS board we still have 3 UARTs available while in the Raspberry Pi UART communication is busy. So, all the configurations to disable the Serial communication an enable de UART to communicate with the sixfab GPRS described in Sixfab GPRS and Raspberry Pi 3 B+ bloc, are not required.
IMPORTANT: GPRS VDD EXT and GPRS POWERKEY are moved. Take a look at the Sixfab GPRS shield pinout (image below) and you will realize that POWERKEY and VDD EXT are pins 37 and 35 respectively. In our equipment, these two pins are moved to pins 33 and 35 of Asus board.