Question for IT people

[Tina10]

So, after some long effort. I made one android app, very simple app which can send data to any server ip address I load at a defined port.

I also attached one PIC with a wifi module which can do the same as the app i.e send data to a server IP at specified port. I want to take my app anywhere outside and be able to communicate with my PIC.

What I have learned upto now is that I need a fixed IP for this, app and PIC can both communicate to this fixed IP and exchange messages with each other. Can someone please explain what exactly is required to make this possible? I read about fixed IP, but no one mentions more than this like providers, what to look for in a provider, approximate costs, any other software needed etc

[comwarrior]

Hi Tina,
I'm going to need a little more information when you say 'outside'...
You say your android pad and pic are both on wifi... but then you say you need a static IP...
If you are still within range of the WIFI then you can still use it as normal.

However, if you are meaning to take your pad to a friends house or using GPRS then thats where we have the fun.
I'm going to assume your setup is you pic is datalogging and connected to your router via wifi. So, in order for a device outside your wifi to communicate to a device on your wifi you need to open a port on your router and direct it to your pic's IP address. You will need to read your router documentation to do this as they are all different.

WARNING: Opening a port on your router can represent a big security hole because anyone in the world will be able to access and communicate with that port.

Next, your router will have a dynamic IP address as standard, if you wish to have a static one then contact your ISP.
However, you can use services such as dyndns to allow a sub domain (for example Tina10.dyndns.org) to always point to your router no matter what it's IP address. But, it's not always that simple, you need to read the guides for setting up dyndns and your routers documentation to see if it will work.

Your pad may not need to have a static IP, if your pic reads the source packet, you will get the source IP address.
However, its still not that simple...
The source IP address will most likely be your 'friends' routers external IP address.
If your using GPRS then the source IP will be valid.

I hope this is of some help...