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I am trying to build my own Arduino board. But for connecting it with a PC a USB to UART bridge was required. Even though I can buy it from sparkfun, I wanted to build my own bridge using some sample ICs. I have a couple of MAX232 IC and have ordered some TUSB3410 IC from Texas Instruments.

So my question is, Can I build a USB to UART bridge using either of these ICs. I am willing to buy some basic electrical components locally.

If this is possible I would be very helpful if you could provide me with some detailed schematics and guide me on this one.

Thanks in advance.

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  • \$\begingroup\$ It looks like with one you can't and with the other it would be overkill. Some reason you need those exact ICs? \$\endgroup\$ – Samuel Jan 16 '14 at 7:38
  • \$\begingroup\$ it is just that I have them handy and thus wouldn't have to spend much money on new ICs and also it would be a learning process for me. That is all. \$\endgroup\$ – BharathYes Jan 16 '14 at 7:58
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You only need the TUSB3410. As mentioned by @Wouter van Oijen, it does require externally provided firmware to operate in the desired mode. Whereas it can either get this firmware from a local EEPROM over I2C or via the USB Host. TI provides this with http://www.ti.com/product/tusb3410 near the bottom "TI WDF USBUART Single Driver (Rev. A) ".

With this you can wire it up to the AVR or Arduino Pro, directly without the RS232 level converters. Just ensure you line up 3.3 and 5.0 volt IO correctly.

Pay attention to the UNO's cap on the DTR for pulsing the reset.

And read all the data sheets and application notes on the TUSB.

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A MAX232 is a level converter. For your purpose you don't need it.

A TUSB3410 is an USB-to-UART bridge, but a programmable one. You will need to get suitable firmware in the chip. I have no idea how you should do this (an I2C EEPROM seems to be an option), but it is certainly possible. There might even be a ready-made firmware that can be downloaded over USB. On top of that, you will need a suitable USB host driver. Prepare yourself for at least a few weeks of heavy digging. Or a few years of studying programming.

The correct chip for you to use is the FTDI232RL. It is not programmable, it simply works. And host drivers are available from the FTDI website.

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  • \$\begingroup\$ Oh.. Thank you for the info. If you don't mind me asking, is there any way I can get free samples of FT232RL IC ???? Since I am very new to this and being a college student I am unable to spend much for my hobbies. It would be very helpful if I can minimise the costs. \$\endgroup\$ – BharathYes Jan 16 '14 at 8:13
  • \$\begingroup\$ AFAIK not. We all want something for nothing, but the chip manufacturers must pay their bills like everyone else. \$\endgroup\$ – Wouter van Ooijen Jan 16 '14 at 8:30
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    \$\begingroup\$ You can just get one of these for $2 . They use CP2102 and can be used with arduino. @BharathYes \$\endgroup\$ – alexan_e Jan 16 '14 at 9:40
  • \$\begingroup\$ FWIW, the FT232 is not so much the correct chip so much as the best supported option. They're certainly fairly standard in homemade *uino boards, but they're not the only option. \$\endgroup\$ – Connor Wolf Jan 17 '14 at 10:27
  • \$\begingroup\$ @Conner strictly speaking you are right, but the TUSB3410 illustrates that not all possible options are viable (for Bharath). IMO no other ready-to-use chip comes with drivers good enough to make it usable in a reasonably wide context (different OSses, versions thereof). \$\endgroup\$ – Wouter van Ooijen Jan 17 '14 at 12:01

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