W55RP20-S2E DHCP address allocation status

Question

Greetings, I am using a W55RP20-EVB-Pico with W55RP20-S2E firmware, controlled via separate MCU over RX, TX lines. I can enter command mode and use the commands, but I am looking for a way to detect when the device has successfully received an IP address from the DHCP server on the network (or report a failure if it doesn't get one). There is an operation status command "ST", but this only responds with "ATMODE". If I use the "LI" command to read the IP address, then until a DHCP address has been allocated it will just return the last static IP address. The workaround I have found at the moment is to deliberately set the IP to 0.0.0.0 before enabling DHCP, then i can check to see it change. But I'm thinking there must be a better way (or it would be nice if the FW did this automatically).

WIZnet AI assistant (automated answer) · Accepted Answer

Hello! It seems like you're trying to efficiently detect when your W55RP20-EVB-Pico device has successfully received an IP address from a DHCP server. Your current workaround of setting the IP to 0.0.0.0 before enabling DHCP is a clever approach, but I understand you're looking for a more streamlined solution. Unfortunately, based on the available documentation, there isn't a direct command that reports the DHCP status or automatically updates the IP address to 0.0.0.0 when DHCP is enabled. The "LI" command, as you mentioned, will return the last known IP address until a new one is assigned. One potential approach could be to implement a periodic check using the "LI" command after enabling DHCP. If the IP address changes from 0.0.0.0 to a valid IP address, you can infer that the DHCP process was successful. Additionally, you could implement a timeout mechanism to report a failure if the IP address does not change within a certain period. For more detailed information or potential firmware updates that might address this feature, I recommend checking the technical documentation or reaching out to the WIZnet community for any shared experiences or solutions. If you have any more questions or need further assistance, feel free to ask! Best regards, WIZnet AI Support Team

JonathanB · Answer

An additional thought: It would also be nice if the static IP address (and subnet mask and gateway) was retained in non-volatile memory, so that if a user changes from static -> dynamic -> static the old values are still there. This is particularly important for user interfaces which are not so easy to change numbers with (I am thinking of one of our own products which only has arrow keys and a select button).