USB host and device with two microcontrollers

[nousernameforme]

Hi all,

I'm working on a project where I have some hardware in a box and I would like it to communicate with a user interface via USB.

The hardware box will probably have an Atmega128 or more likely a 2560. The user interface is a simple few buttons and LED's so possibly only a small atmega or an AVR USB chip?

The device will also need to plug into a PC for firmware updates via the same USB connection that is used for the interface (unplug interface and plug into PC).

There seem to be some auxiliary chips around that deal with the protocol stacks etc and turn the connection of a microcontroller into a serial port when plugged into a host, but what do I do if I want the host to be the microcontroller?

My current idea is to have the hardware as a USB device, the interface as a host. Then the hardware unit would plug into the PC as a host or the interface as a host.

Any suggestions? Either on the setup or the easiest way to create a microcontroller USB host.

 

[bobsanjose]

Hi,
you should check for USB OTG. OTG stands for On The Go and it means that this kind of USB can switch from being a device to being a host. There are some stand alone USB OTG devices from NXP I think they are ISP136? . The LPC2468 also offers such an interface integrated on an ARM7, really no need for the ATMega!
Bob

 

[elec4fun]

For host capabilities look at here :

**broken link removed**

Regards,
Franck.

 

[FvM]

Hello,

Atmel AT90USB1287 has also limited USB HOST (OTG) capabilities, offering a single chip solution for the said application. They also have some basic examples for so-called "dual-role" applications and a C library. A good thing with Atmel is an USB bootloader that is initially programmed to all shipped devices and could be used also in final application with sufficiant memory space.

Regards,
Frank