SPI Length

[Parggoo]

Hello, 

I have successfully managed to connect accelerometer adxl345 to Labview with Arduino with SPI(4-wire connection+3.3V+GND) and get the right values.I use wires with length 15cm each. I want to increase this length, but every time I add new wires the accererometer seems to stop working. To be more specific it is powered on but it gives no values. I have read that distance affects the SPI but can this be the problem when increasing the distance by only 15cm ? 

[xc6lx45]

Hi,

unfortunately, it can.

Try to put a 100 ohms resistor in parallel with the CLK input at the accelerometer board end to ground.

CLK is most likely the most sensitive of the signals when reflected edges cause double-triggering.

[mishu]

Hi,

Try to reconstruct the signals using trigger schmtt circuits, it should work. Also try to lower the SPI CLK if you dont  need high sampling rates.

M