building my own usb interface

Projects General Guidance
1

I am using my own ATMEL328 on breadborad for building projects and i would like to learn how to make my own usb interface to go with it . can someone guide me on this ?

thanks

2

Hardware or software?
Do you mean adding an FTDI (or similar) Serial-to-usb chip, or use something like V-USB and do it in software?
http://www.obdev.at/products/vusb/index.html

3

Seriously not worth mucking about for US $2.29 and in fact I'll vouch you could not possibly make it for that price.

4

Paul__B:
Seriously not worth mucking about for US $2.29 and in fact I'll vouch you could not possibly make it for that price.

But that's not the issue. If you use an off-the-shelf FTDI chip, it'll always be a serial port with a generic PID/VID. Sure, some might be configurable with a different PID/VID, but in the end you are still dealing with a COM port. If you're doing it yourself, you can use custom end points and define your own PID/VID.

I've recently done a project with a ATTiny85+V-USB and not having to deal with COM ports for a more "final" product is very nice. Just plug-in, load your customized driver and off you go. No COM port, no serial I/O. Just USB.

FTDI are great for prototyping, but there's more to USB then just serial, you know...

5

int2str:
FTDI are great for prototyping, but there's more to USB then just serial, you know...

I do think you are getting a bit esoteric there! My guess is that the OP does want a basic serial port simply so that he can use the Arduino IDE, which is in serial COM port mode, for programming and communication.

Incidentally, the "cheapie" board I referenced (you can ferret it out for half the price, but I deliberately cited the one that does not require a bug-fix on the board) uses the CP2102 rather than the FTDI, but I think your reference to "generic" applies though "VID customised" FTDI chips are available,

1 Like
6

@aliyesami, if all you want to do is make a USB connection from your breadboard to a PC use an FTDI cable.

I made a fridge controller on a piece of Veroboard. I included pins that I can plug the FTDI cable onto if I need to upload a new version of the program or read data that is being collected.

...R

7

I am not looking for serial port , what i want to do is to connect a usb adaptor to my atmel328 on board device and then connect an usb gprs/gsm modem like Huawei and be able to send texts to my phone.
since iam building my own circuit board i dont want to use an existing usb module .

thanks

8

Sparkfun, and others, sell USB Host shields. Sparkfun, at least, makes the schematics available.

9

hi Paul can you give me a link or product code there , i searched on their site with keyword "USB" but i cant find one.

thanks

10

i searched on their site with keyword "USB" but i cant find one.

Why? I gave you the search term - "USB Host".

11

awesome!
trying to understand the schematics, so for my need i dont need the hex-converter and GPIN and GPOUT connectors ?

12

also read your comments on my other posting saying writing usb drivers is not an easy task. so how do people use usb in their projects do mostly use these ready made usb sheilds ?
are there no usb driver code out there for atmel and the max3421E chip that i can use?

thanks

13

http://www.circuitsathome.com/mcu/programming/interfacing-arduino-to-a-cellular-phone

14

also can i do something like this : have a serial to usb interface to talk to a usb device. would building such kind of interface will also require writing drivers ?