LWIP DHCP Configuration on CubeMX
Hi,
I am trying to configure DHCP on my STM32F746G-DISCO board, but despite several attempts and even after setting up my DHCP server or configuring my router, I can't get a dynamic IP for my MCU. I can make it work with a static IP, but I would like to test it with a dynamic IP.
The project is simple: just a UDP server. I am not using an OS, just a small piece of code that initializes and waits for the DHCP to assign an IP before continuing. However, on Wireshark, I see that the DHCP Discover message is sent repeatedly without ever receiving a DHCP Offer or DHCP Request response.
There aren't even any tutorials showing how to configure just DHCP on CubeMX, I can't find anything on this topic. Most examples use a static IP.
This is the part of the code where we notice the DHCP anomaly
void udpServer_init(void) {
struct udp_pcb *upcb;
upcb = udp_new();
if (upcb == NULL) {
printf("Error creating UDP PCB!\n");
return;
}
if (udp_bind(upcb, IP_ADDR_ANY, 5555) != ERR_OK) {
udp_remove(upcb);
printf("Error UDP Bind!\n");
return;
}
udp_recv(upcb, udp_receive_callback, NULL);
while (!dhcp_supplied_address(&gnetif)) {
HAL_Delay(100);
}
struct dhcp *dhcp = netif_dhcp_data(&gnetif);
printf("DHCP IP address: %s\n", ip4addr_ntoa(&dhcp->offered_ip_addr));
printf("DHCP Subnet mask: %s\n", ip4addr_ntoa(&dhcp->offered_sn_mask));
printf("DHCP Default gateway: %s\n", ip4addr_ntoa(&dhcp->offered_gw_addr));
}
Note that dhcp_start(&gnetif); was correctly executed earlier in MX_LWIP_Init() as follows:
int main() {
.......
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_LWIP_Init();
/* USER CODE BEGIN 2 */
udpServer_init();
/* USER CODE END 2 */
........
...
while (1)
{
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
MX_LWIP_Process();
}
return 0
}
The code stays stuck in the loop, proving it never receives an IP via DHCP.
Do you have any suggestions or advice to resolve this issue?