FTDI FT232RL USB UART interface

[GartnerProspect]

Has anybody used one of these or a variation there-of?

I'm sick of DB-9 -> Serial converters and even the super super cheap used laptops have USB now so I'm looking for alternatives. Post up what you know, from what I've seen this is one of the more popular and availible solutions. And the drivers are royalty free, basic COM, so shouldn't change anything on the software side for use on megasquirt.

Thanks!

[jbelanger]

I've used this board from SparkFun:



It's been painless to use with no problem with either the drivers or the device itself.

Jean

[GartnerProspect]

You're a convincing guy. I'll get the protoboard to play with and work the chip into my designs.

Thanks a lot.

[jbelanger]

I'm not trying to convince , just reporting my own experience (which is NOT extensive on this device). But I don't remember hearing anything bad about the FTDI chip.

Jean

[Fred]

My chinese usb>rs232 has FTDI inside, it's been good also. I think I would choose similarly if I were putting USB in my future EMS solutions.

[GartnerProspect]

That's good to hear. I just wanted to hear some more good words from you guys before I jumped into it.

Haven't really heard anything bad about it yet.

[GartnerProspect]

Also while I have everybodies attention.

I was looking at it and was considering what other sort of neat things could be done using this type of comms chip over at normal RS232 serial driver.

You now have 5v availible to the board so in theory, it might be possible to do a bench-edit or Key-off edit without external power... though I don't know if the USB bus has the snot in terms of mA to do it without some on-board trickery to power the MCU only.

You also have a unique to-chip hardware ID. This could be useful for tuning software.

I might hook up my laptop to a half dozen or more ECU boxes throughout the year. It would be great if the software would read the USB-ID and automatically configure things appropriately for each particular system. Automatically bring up notes on the install, etc...

Just some things sloshing through my head.

[thebigmacd]

Also while I have everybodies attention.

I was looking at it and was considering what other sort of neat things could be done using this type of comms chip over at normal RS232 serial driver.

You now have 5v availible to the board so in theory, it might be possible to do a bench-edit or Key-off edit without external power... though I don't know if the USB bus has the snot in terms of mA to do it without some on-board trickery to power the MCU only.

You also have a unique to-chip hardware ID. This could be useful for tuning software.

I might hook up my laptop to a half dozen or more ECU boxes throughout the year. It would be great if the software would read the USB-ID and automatically configure things appropriately for each particular system. Automatically bring up notes on the install, etc...

Just some things sloshing through my head.

USB provides 500 mA @ 5V. Should be plenty no?

[GartnerProspect]

Ahh. Good catch.

For some reason I had a 100mA figure in my head, which also would be more than plenty for a basic board design...

But 500mA is right, though it should consume no more than 100mA on plug-in. The FT232RL looks like it has a configurable output to handle the power up to keep plug in under 100mA for high power devices. So the only major design consideration seems to be delaying CPU power up and preventing feeding current back into the USB bus.

Seems pretty reasonable.

Anybody think it's worth it?

[Fred]

Um, as I understand it, USB hosts report their current capability to the device when it attaches. Or is 500mA a minimum "you must meet this to be USB" spec? I know laptops are weak when it comes to USB power, some more than others, but most of them.

Either way, the CPU draws a significant chunk! I posted it in my hardware thread, but I forget the figures now. 300mA rings a bell.

It's a nice idea, but I'm not in favour of things like MS's flood clear mode. Basically anything that is there only for initial setup shouldn't be paid much attention IMO.

Admin.