stm32guide

Steps to Create a Sample STM32 USB Host Project:

Visit https://www.st.com/content/st_com/en.html This is STMicroelectronics formal site; If you have business email, you can sign up and log in with it. But if you have only gmail or hotmail, you can download as a guest. The site will be slightly slow and you should wait for a while with every interactions.

1. Download STM32CubeMX: Go to the STM32CubeMX download page. Url is https://www.st.com/en/development-tools/stm32cubemx.html Download latest version for Windows.(The page is so long and Find "Get Software" at the middle of the page) If your email is personal mail(like gmail or hotmail), you should log in as guest and follow the link from your inbox. Install STM32CubeMX on your computer.

2. Download STM32CubeIDE:
   You can download STM32CubeIDE from this link. https://www.st.com/en/development-tools/stm32cubeide.html You can finish download as the first one.

3. Download USB Host Library: The USB Host library is available as part of the X-CUBE-USB-Host package, which includes the necessary drivers and examples. Go to ST's USB Host Middleware page. You can either download the package or use STM32CubeMX to configure and generate the necessary code for USB Host CDC functionality. Url is https://www.st.com/en/embedded-software/x-cube-usb-pd.html This Url is for C-type.

Instructions to Generate the Project:

Launch STM32CubeMX and create a new project:

Select your STM32F4xx microcontroller (e.g., STM32F407VG). Configure USB Host:

In the “Pinout & Configuration” tab, select USB_OTG_FS as Host. In the “Middleware” section, enable USB Host and select CDC (Communication Device Class). Generate Code:

Go to the "Project" tab and configure your project settings (name, location, IDE). Click Generate Code to create the project files. Open STM32CubeIDE:

After the project generation completes, open it in STM32CubeIDE or another supported IDE (e.g., Keil MDK). Modify the Code:

Inside the generated project, modify the USB Host initialization and communication handling code (as shown in the earlier response). The USBH_CDC_Itf file should be modified to suit your modem communication logic (sending/receiving AT commands). Build and Debug:

After writing your custom logic (sending AT commands to the modem), you can build and flash the code to your STM32F4 board.

STMicroelectronics/stm32-usbx-examples https://github.com/STMicroelectronics/stm32-usbx-examples

Guide

To use a USB modem (e.g., a USB modem device with a chip like the Huawei E1750 or similar) on an STM32F4xx microcontroller for landline communication (e.g., sending/receiving SMS, making calls), you will need to follow these steps:

Overview: Set up STM32 Development Environment: Ensure your STM32F4xx development environment is ready. USB Host Interface: The STM32F4xx will need to communicate with the USB modem as a USB host device. Configure USB Host for CDC (Communication Device Class): USB modems often use CDC-ACM (Communications Class Abstract Control Model) or similar for serial communication. Serial Communication: Once the STM32 recognizes the modem as a virtual COM port, it can use serial communication to send commands (e.g., AT commands) to the modem to control it. AT Commands: You will send AT commands (e.g., AT+CSQ, ATD, ATH, etc.) to control the modem to make calls, send SMS, or check signal quality. Step-by-Step Guide

1. Set up STM32 Development Environment Make sure you have the necessary tools installed:

STM32CubeMX for hardware initialization and peripheral configuration. STM32CubeIDE or Keil MDK for writing and debugging code. STM32F4 USB Host libraries: These can be found in STM32CubeMX or STM32CubeIDE. 2. Configure USB Host Mode for CDC Open STM32CubeMX and select your STM32F4xx device. Enable USB Host: In the “Pinout & Configuration” tab, select the USB Host feature. Under the “Middleware” section, select USB Host and enable CDC (Communication Device Class). Generate the code by clicking on the “Project” tab and selecting your IDE (e.g., STM32CubeIDE or Keil). Open the generated project in your chosen IDE and build the project. 3. Code to Initialize USB Host and CDC The USB Host will detect the connected modem. You need to implement code that sends and receives data via the virtual COM port.

USB Host Initialization Code c Copy code #include "usb_host.h" #include "usbd_cdc_if.h"

// USB Host variables USBH_HandleTypeDef hUsbHostFS; extern CDC_ItfTypeDef CDC_ItfDesc;

void USBH_UserProcess(USBH_HandleTypeDef *phost, USBH_UserStatus state) { switch (state) { case USBH_USER_DEVICE_ATTEMPT: // Device Attached break;

    case USBH_USER_DEVICE_DISCONNECTED:
        // Device Disconnected
        break;

    default:
        break;
}

}

// Initialize USB Host void USB_Host_Init(void) { USBH_Init(&hUsbHostFS, USBH_UserProcess, USBH_SPEED_FULL); USBH_RegisterClass(&hUsbHostFS, USBH_CDC_CLASS); USBH_Start(&hUsbHostFS); }

int main(void) { HAL_Init(); SystemClock_Config();

// Initialize USB Host
USB_Host_Init();

while (1)
{
    USBH_Process(&hUsbHostFS);
    // Further communication handling
}

} This code initializes the USB Host and starts the CDC class to communicate with the connected USB modem.

4. USB Modem Communication (Sending/Receiving AT Commands) Once the USB Host is initialized and the modem is connected, you can use CDC_Transmit_FS and CDC_Receive_FS to send and receive data through the virtual COM port.

Example to Send AT Command to the Modem c Copy code // Send AT Command to the modem void Send_AT_Command(char cmd) { CDC_Transmit_FS((uint8_t)cmd, strlen(cmd)); // Send command over USB to modem }

// Example of usage Send_AT_Command("AT\r\n"); // Sends 'AT' command HAL_Delay(1000); // Wait for response

Send_AT_Command("AT+CSQ\r\n"); // Request signal quality HAL_Delay(1000); // Wait for response Example to Read Response from the Modem You can read responses from the modem by implementing a callback or polling method.

c Copy code #define MAX_RECEIVE_LENGTH 64 uint8_t usb_rx_buffer[MAX_RECEIVE_LENGTH];

void USB_Receive_Data(void) { int length = CDC_Receive_FS(usb_rx_buffer, MAX_RECEIVE_LENGTH); if (length > 0) { usb_rx_buffer[length] = '\0'; // Null-terminate the string printf("Received: %s\n", usb_rx_buffer); // Process response } }

// Call this function periodically to check for incoming data USB_Receive_Data(); 5. Handling Responses The modem will send responses after each AT command. Typically, these responses will be in text format. You can parse these responses to handle different situations, such as checking if the modem is ready, signal strength, etc.

For example, if the modem sends a signal quality response after AT+CSQ, it might return something like +CSQ: 15,99. You can parse this string to extract the signal strength value.

6. Sample Code to Make a Call or Send an SMS Once you have communication established, you can use various AT commands to control the modem.

Example to Send an SMS c Copy code // Example function to send SMS void Send_SMS(char *phone_number, char *message) { char cmd[256];

// Set SMS mode to text mode
Send_AT_Command("AT+CMGF=1\r\n");
HAL_Delay(1000);

// Send SMS command
sprintf(cmd, "AT+CMGS=\"%s\"\r\n", phone_number);
Send_AT_Command(cmd);
HAL_Delay(1000);

// Send the message text
Send_AT_Command(message);
HAL_Delay(1000);

// Send CTRL+Z (0x1A) to send the message
uint8_t ctrl_z = 0x1A;
CDC_Transmit_FS(&ctrl_z, 1);
HAL_Delay(1000);

} Example to Dial a Phone Number c Copy code // Example function to make a phone call void Dial_Phone(char *phone_number) { char cmd[256]; sprintf(cmd, "ATD%s;\r\n", phone_number); // ATD<phone_number>; to dial Send_AT_Command(cmd); HAL_Delay(1000); } 7. Additional Resources and URLs STM32 USB Host CDC Example: The STM32CubeMX tool provides a USB Host CDC example that can be customized for your needs.

STM32CubeMX STM32 USB Host Library AT Command Set Documentation: Depending on your modem model (e.g., Huawei, ZTE), you can find the specific AT command set in the modem’s documentation. Common AT commands for SMS and dialing include:

AT+CSQ - Check signal quality. AT+CMGS - Send SMS. ATD<phone_number> - Dial a number. ATH - Hang up the call. USB Host on STM32: STM32CubeMX has various examples of using the USB Host feature with peripherals like mass storage or CDC devices. You can adapt the CDC-based examples for USB modem communication.

STM32 USB Host CDC Example Modem-Specific AT Commands: You may need to refer to the documentation of your specific USB modem (e.g., Huawei E1750) to ensure the correct AT commands.

Conclusion: In summary, the STM32F4xx can interact with a USB modem in CDC mode via USB Host, and you can use AT commands to control the modem for SMS or voice communication. The STM32CubeMX environment helps set up the necessary configuration, while STM32CubeIDE or Keil can be used for writing and debugging the code. Make sure to test the modem with basic AT commands before implementing more advanced functionality like sending SMS or making calls.