msp430 & cell phone

Gaston,

USB is Master-Slave system. When you connect a usb device to PC, the PC is the master and the usb device is the slave. In short, your MSP430 should act as master.

There was a new USB standard released couple of years ago called 'USB on the go'. Devices with On the go feature can connect to other devices, like camera to Printer etc.

I am new to MSP430. But I'll take a bold step and say MSP does not have On the go feature. So you will have to use another USB chip as an intermediary between the Nokia and the MSP. Something like the Maxim MAX3421E. The MAX3421E acts as the USB master and allows you to connect your cell phone.You can talk to the MAX via SPI bus.

To accomplish this, you need to learn about USB enumeration, which is non trivial. Takes some time and effort.

Hi Gaston,

you should opt for using Stellaris Cortex M3 devices (http://focus.ti.com/mcu/docs/mculuminaryprodoverview.tsp?sectionId=95&tabId=2486&familyId=1755&DCMP=Luminary&HQS=Other+OT+stellaris) instead of MSP430 because you can have Master, device, and or OTG (on-the-go; i,e, http://focus.ti.com/docs/toolsw/folders/print/ek-lm3s9b90.html ).

Rgds
aBUGSworstnightmare

USB is a very complex thing. a VERY complex thing. Most of this complexity is on the host side, while the client can be very simple. So being an USB client, is no problem for the MSP. There's not much to do. You say your ID and the host knows what you can do or not. So all tha tis left to do is to implement the functionality you want to provide.

Being a host, however, is unbelievable complex. Imagine that Microsoft didn't manage to build up a proper USB support for Win95. Basic communication was there, but almost every devices was in the unknown category. And under current operating systems, the USB stack requires megabytes and megabytes of code and data (this is NOT counting the device-specific drivers for using their functionality).

The cell phone, too, is a client. Simple, only supporting this small fraction of the USB standard it wants to support and providing only the functionality it wants.

If you want to connect cell phone and MSP, one of them must be the host. The cell phone won't. So the MSP has to. And I doubt you'll fit the required code into any MSPs flash.

There is, however, an on-the-go standard that allows two clients to connect with each other directly. It removes the support for USB HUBs and most fo the rest of the things an USB host needs to support. It is, however, still way more complex than just being a client.

If the cell phone supports this standard, then there is a chance you'll be able to implement the same for the MSP and establish a connection. It's a huge project still.

So OTG requires a special PHY layer too, and not 'just' the protocol on software side? Well, then of course "abandon all hope!" :)

Gaston, you might try the Mbus  point on an older cell phone.

Just an idea.

jeff.