To get up and running quickly with this sample, follow the steps below:

1. Insert the activated IoT SIM into the SIM Slot

2. Attach the antenna

3. Flash ./Dist/atdevkitgsm.bin in to your dev kit.

4. Open Serial to view SIM Connection status

For a detailed write up, read below

• See overrall config as shown below

• Set PB15 to GPIOOutput as shown. This will be your GSM Power Key.

• Also set PC13 to GPIOOutput; this is the on-board LED.

• Set HSE to Crystal/Ceramic Resonator and disable LSE as shown

• Set serial mode to Asynchronous for both USART1 and USART2 and ensure gloabl interrupt is enabled under NVIC Settings

• See below clock configuration.

  • Toggle PLL and PLLCLK
  • Set input frequency to 8Mhz

• You might want to set the multiplier PLLMul to 11 or above then click Resolve Clock Issues

• Under Project Manager ensure Generate peripheral initialization... is checked

• Then inside Advanced Settings Set USART driver to LL
  

SAVE AND GENERATE PROJECT

• See the APN configuration inside ./Core/Src/main.c

• Note that the line shown below is commented under ./Core/Src/syscalls.c

extern int __io_putchar(int ch) __attribute__((weak)); 

• Also note that an IRQ handler is required for USART1; see ./Core/Src/stm32f1xx_it.c.

• Note the differences under ./Core/{*}/usart.{*}