I'm using a UNO with a RS485 shield to talk to three industrial flow meters. Upon asking the flow meters of their total volume, the data is stored on a SD shield with a real time clock. Adafruit datalogger Three numbers are logged and time stamped once a day. Once a month, the data needs to be read from the SD card.
So far, this has worked well. However I'm wondering if I could also have a USB shield where, when prompted, the data from the SD card could be copied to a USB flash drive. This way, I could use a USB plug on the front of the cabinet. The SD card would not have to be removed to be read, as it's buried in the cabinet.
I looked for examples and discussions about this, but I didn't find anything directly relevant - or I don't know what I'm looking for, which is more likely.
Any thoughts, or correct nomenclature that I should be using while searching?
What about using the USB connection to print all file content to the serial port and log all print outs with a terminal program. I use this terminal by bray++
Press log to log to a file and then let UNO print the entire file to serial port. You can use custom baud rate. I am using 200,000 so files print faster. This needs no expensive USB host shield. On your arduino side, have the loop look for a character, or any character from serial port. If there is a character, read it and print the whole file to serial port.
Yes, you can write to a USB card.
A USB host shield is needed so your project can be a USB Master and control a USB stick.
See the Products page for the Arduino version, and Sparkfun has one also.
Not sure how much code exists to drive the card.
Thanks for the info guys - two directions to check into. The terminal method is intriguing, but the guy taking the readings probably won't be hauling a laptop through the lab to get the data. He just want's to stuff a USB stick in the socket and push a button.