USB interface

wrote in news:9pDwl.14738$ snipped-for-privacy@flpi148.ffdc.sbc.com:

There are many products that connect to a computers USB port and provide one or more serial ports. The drivers that come with them often provide a virtual serial port to programs running on the computer.

If you are looking for something to embedd in a design, look at

Robert H.

Acutally I can put the routine to read the serial port into the program.

Bob

I can get data retention currents as low as 2 ua. A battery is required anyway when operating.

Bob

FT245XX.

Bob

You realize you are using a 50$ RAM that can run at 100MHz for something a 2$ bottom of the barrel USB flash drive is meant for?

OK... check out something like this:

If you start finding yourself having to add a bunch of logic to interface that chip to your SRAM, you might re-think Linnix's suggestion to just use a microcontroller instead. If you already know how to program, it's generally faster to build "glue logic" in software than in hardware, and many microcontrollers have built-in USB interfaces... or can very easily be interfaced to a RS-232 to USB converter chip such as FTDI's FT232 series.

---Joel

this:

Or, check out this ready to use 70g vibration data logger with detachable USB key. We are looking into optional 16 M bytes serial flash (spec provided)

We have already done it.

My customer is going to get angry for this discussion, but I did not start it.

Looks nice. If the OP can buy one of those from you cheaply enough, I'd recommend doing so.

You forgot about the temporal mid storage point that he WANTS to have. If he gathers the data in one location, and THEN takes it to the PC for transfer, your solution isn't one... at all. There must be a data-to-storage step BEFORE the PC transfer.

Yet another drawback. Yet another reason to write to a device that does not require power to retain the data.

If he simply writes files out to a standard USB stick of ANY size, he will be in data integrity heaven. I suggested this in an earlier post, but did not mention this additional volatility as a reason. It happens to be the best reason.

When was the last time you looked at the original post made in a thread? He wants to make a PORTABLE device and interface to a computer LATER on down the line. Sheesh!

Or solar, or a potato(e)... or an apple even!

STILL a non-volatile solution is best for overall data integrity.

this:

Jeez, Louise, couldn't you have used button batteries with that? Or does the USB stick draw too much?

You did, however, join it. D'oh!

Seems that you have a personality defect.

I assumed the OP would keep his 4 megabytes of RAM and his counter, and would just tristate the counter when he was ready to let the uP take over the readout.

Shame on me for assuming.

:-)

Steve

And no storage required in the device.

Bob

says 175mA active, 25mA standby. Where did you get the 2uA data retention?

this:

The USB uC is only needed for data downloading. The LCD uC and sensor take 4mA to 5mA. Button cell onlt last for days. AAAs lasts for weeks.

that

F*ck off, RichTard.