When I saw this, I thought that this would be the shield I need to get my mobile phone talking with arduino through cable. And that is what this post is about.
- Nokia phone ( anyone with usb port, i used n95)
- Usb Host Shield form Circuits@home
- Firstly, i installed the "glass term" example program from Symbian SDK, which is an good example of Serial communication.
- I tested the communication with HyperTerminal on windows. it worked! The phone side is done!
This side is s little more tricky because you need to have some knowledge of USB protocol. I use this document to get the information i needed:usb-in-a-nutshell
- When doing step 2 of phone side i sniff usb communication, using snoopPro to get how information flows back and forth between arduino and pc, and to check from what endpoint the data leaves the phone. This endpoint is controlled by an interface which by turn is controlled by a class interface.
- Supposing that the endpoint number was known, i used an example from circuits@home which allow me to get device descriptor to make sure if it exists in arduino configuration speed. The configuration speed in the connection between the phone and the pc is one, and between the phone and the arduino can be another. And the configuration speed can change the struture of interfaces and endpoints.
- Luckly, the configuration speed was the same, so the endpoint number also will be the same. I used a Bt dongle code example from circuits@home and modified some instructions, as to configure the class interface.
- After all this work, i test it. it worked, but not in the first try :S
- My worse problem was to understand usb protocols and configurations.
Hope you enjoy.