Feb
21
2013
Posted by kll · In Arduino Projects · 3528 Reads ·
From
DFRobot
use the interface shield and a 4GB Kingston uSD card
Interface shield 453THB

4GB Kingston uSD card 500THB

for the software used the SD library from ARDUINO
the device should collect data ( A0,A1,A2) in an adjustable schedule
a easy MENU software allows

at power up, reset, start ARDUINO terminal
the sample speed setting is readback from a config file on uSD card
instead of that internal terminal software
( what always resets the ARDUINO)
i like to use the HTERM.
with this and the menu point
s list saved records
you can playback the recorded data to terminal and
save them there as terminal log ( even as ASCII EXCEL CSV file again )
( more easy as to check the data by cardreader, file copy..)
for the hardware:
i recheck the SD card interface between original ETHERNET shield
and that DFRobot interface shield
and found that on the original there are resistors used to
bring down the 5V AVR outputs to the 3V3 level of SD card power
while these are here missing it still seems to work.
data recording with ARDUINO?
well, there is no RTC, and a measurement data record without a timestamp
is questionable, so its of limited use.
the only timer is the millis(), a unsigned long value counting the milli seconds after last reset.
This number will overflow (go back to zero), after approximately 50 days.
I see a dedicated data collection shield at
adafruit
pls see
code
I mentioned above already the wiring of SD card reg. 5V / 3V3
but when i started to test uSD AND LCD
i run into trouble.
There is no problem with the pins / wiring.
There is no problem with the libraries.
But it does not work together because of POWER problems.
when there is communication with SD card, LCD dimms.
Or the SD card can not be init ( but not got damaged ).
Even with the SD card can not be used on the ethernetshield ( together with ethernet) for wiring reasons it is a similar problem.
anyhow i was not aware of that SD cards are so powerhungry, but should run on 3V3.???
next i want work on my own shield extension with instrument opamp amplifier
pls see
layout using LM324
but it would be more easy if i use AD623