STM32F411 USB CDC Host
I have a laser engraver that runs on an ESP32 S2 Mini microcontroller. It has the following signature: “Espressif CDC Device” and emulates a COM-type serial port. I had two identical cables; if I connect my engraver to my PC via a serial program (NinjaTerm), I can control GRBL. I cut one of these cables, and they have four wires: VBUS, D+, D-, and GND. After crimping some connectors onto the ends of the wires and testing the cable connected to the port to distinguish between my D+ and D-,
Now I’d like to put an STM32F411 (WeAct BlackPill v3.0) between my engraver and my PC to control my homemade Z-axis. The PC side is on a UART port of the STM32 connected to a CH340, and on the engraver side, a USB (D+/D-) CDC Host (Note: I’m not using the USB-C connector already soldered onto the BlackPill). The UART programming side worked perfectly. Where it’s getting stuck is on the CDC side… no response…
#include <stdio.h>
#include <string.h>
#include <stdarg.h>
#include "usbh_cdc.h"
/* Private variables ---------------------------------------------------------*/
UART_HandleTypeDef huart2;
void HAL_UART_Printf(UART_HandleTypeDef Uart, const char *Format, ...)
{
unsigned char TmpStr[128];
va_list args;
va_start(args, Format);
vsprintf((char*)TmpStr, Format, args);
va_end(args);
HAL_UART_Transmit(&Uart, TmpStr, strlen((char*)TmpStr), 10);
}
extern USBH_HandleTypeDef hUsbHostFS;
extern ApplicationTypeDef Appli_state;
void ParseCommand(char *line)
{
if (strncmp(line, "M900", 4) == 0)
{
return;
}
if (strncmp(line, "M901", 4) == 0)
{
return;
}
char txbuf[150];
sprintf(txbuf,"%s\r\n",line);
USBH_CDC_Transmit(&hUsbHostFS, (uint8_t*)txbuf, strlen(txbuf));
}
char UartCmd[256];
uint8_t UartCmdCount = 0;
uint8_t UartRx;
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
if (huart->Instance == USART2)
{
HAL_UART_Printf(*huart, "Uart2Receive\r\n");
if (UartRx == '\n' || UartRx == '\r')
{
UartCmd[UartCmdCount] = '\0';
ParseCommand(UartCmd);
UartCmdCount = 0;
}
else
{
UartCmd[UartCmdCount++] = UartRx;
if (UartCmdCount > 256) UartCmdCount = 0;
}
HAL_UART_Receive_IT(huart, &UartRx, 1);
}
}
#define RX_BUFF_SIZE 64 /* Max Received data 1KB */
uint8_t CDC_RX_Buffer[RX_BUFF_SIZE];
void USBH_CDC_RxCpltCallback(USBH_HandleTypeDef *phost)
{
HAL_UART_Printf(huart2, "CDC Receive\r\n");
/* Get the length of data received */
//uint16_t length = USBH_CDC_GetLastRxSize(phost);
/* Copy data to your FIFO/Ring Buffer for non-blocking processing */
//Process_Rx_Data(rx_buffer, length);
//if (length > 0)
//HAL_UART_Transmit(&huart2, CDC_RX_Buffer, length, 10);
/* Re-arm the CDC receive interrupt for the next packet */
USBH_CDC_Receive(phost, CDC_RX_Buffer, sizeof(CDC_RX_Buffer));
}
/****** MAIN PART *********************/
MX_GPIO_Init();
MX_USART2_UART_Init();
MX_USB_HOST_Init();
/* USER CODE BEGIN 2 */
HAL_UART_Printf(huart2, "\x1b[94mWelcome\r\n");
HAL_UART_Receive_IT(&huart2, &UartRx, 1);
USBH_CDC_Receive(&hUsbHostFS, CDC_RX_Buffer, 1);
static uint8_t once = 0;
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
/* USER CODE END WHILE */
MX_USB_HOST_Process();
/* USER CODE BEGIN 3 */
HAL_UART_Printf(huart2, "My name is %s and I`ve %d year old.\r\n", "Nobody", 30);
HAL_Delay(1000);
if (Appli_state == APPLICATION_READY)
{
if (!once)
{
HAL_UART_Printf(huart2,"CDC READY\r\n");
char cmd[] = "$$\r\n";
USBH_CDC_Transmit(&hUsbHostFS, (uint8_t*)cmd, strlen(cmd));
once = 1;
}
}
}
/* USER CODE END 3 */