Wireshark is an awesome tool especially for debugging HTTP requests done by small embedded devices. Typically the developers of http libraries on these platforms typically develop a very minimal subset of the protocol for their use case.
Debugging any compatabilty issues can be a pain in the butt, this is where wireshark comes in. It enables to look at what was transmitted across the wire and with a few rules pick up anomolies.
I have put together a few handy recipes.
This one is a brief summary of the HTTP requests.
sudo tshark -d tcp.port==8080,http -R 'http.request or http.response' -i lo0 ip and port 8080
This one has a full dump of the web request.
sudo tshark -V -O http -d tcp.port==8080,http -R 'http.request or http.response' -i lo0 ip and port 8080