I'm new to the Arduino and am confused about when a resistor needs to be inserted into a circuit to protect the sensor or Arduino. At the moment, I'm working on getting a SPC1000 pressure sensor (using the SparkFun breakout) hooked up. According to an older thread (?num=1213217330/0, n00b SPI problem), you connect CSB to digital 10, MOSI to 11, MISO to 12, and SCK to 13. Do I need a resistor to ground on each of these connections to the Arduino?
i.e. is it:
CSB --- d10
CSB --+-- d10
+-- resistor -- GND
How does one choose which resistor?
VTI SCP1000 Series
Absolute pressure sensor
Only thing I can see mentioned here is bypass capacitors http://www.sparkfun.com/datasheets/Components/scp1000_product_family_specification_rev_0.08-3.pdf on page 34. The Sparkfun breakout board supplies those.
There also needs to be a solid signal ground between the sensor and the Arduino. I don’t see anything else mentioned on the four SPI signal lines in the research I’ve done.
Basic explanation of SPI from embedded.com http://www.embedded.com/columns/beginerscorner/9900483
The connections for SPI would be the same as in the SPI-EEPROM demo for Arduino http://www.arduino.cc/en/Tutorial/SPIEEPROM which also explains how SPI works.
Thanks for the information on the SPC1000. I do have the breakout board, so it sounds like all I need to do is hook up the four signal lines to four digital ports, ground and 3.3V.
I see resistors in a lot of sensor circuits and I wasn't sure if this was a general protection mechanism, or something required by particular sensors.