Thinkulator
commented
7 years ago I was able to get UDP Multicast working for UPNP recently, it was not a ton of work, but required a few modifications to some non-project files that I still need to clean up.
Here's the details for now: in your .energia directory (where the compiler and libraries are stored): packages/energia/hardware/tivac/1.0.2/libraries/Ethernet/lwip/opt.h
- Change define for LWIP_IGMP from 0 to 1
- Add a define for random number generator:
define LWIP_RAND lw_random_num
packages/energia/hardware/tivac/1.0.2/libraries/Ethernet/utility/tiva-tm4c129.c Add function for random number generator long lw_random_num(){ return 0xDEADBEEF; //I cheated to get it working, I have not come back to fix it yet. }
This gets the core of IGMP multicast working - now we can join multicast groups in our code
include "lwip/igmp.h"
ip_addr_t ipaddr; ip_addr_t ipgroup;
//Join the multicast groups used for UPNP device discovery ip_addr_set_any(&ipaddr); //multicast listen on all ip addresses IP4_ADDR(&ipgroup,239,255,255,250); Serial.println(igmp_joingroup( &ipaddr, &ipgroup )); IP4_ADDR(&ipgroup,239,11,3,8); Serial.println(igmp_joingroup( &ipaddr, &ipgroup ));
Both of the printlns should output 0 (success).
With this in place, any UDP listener will pick up UDP multicast packets - and I was able to successfully emulate a belkin Wemo device using the TM4c1294.
If there is interest, and IGMP can be enabled by default (or configurably) - I would be willing to turn this into a proper library.
I wonder if it is possible to implement UDP Multicast over Ethernet UDP.h library with TM4c1294 I have not find any doc neither example related If there is any example of that implementation I will appreciate it Thanks