ADXL1001/1002 motion indication.

Question

Dear Miss, Mister. 
 I'm confused about the axix of sensitivity of your ADXL1001/1002 product. 
 When moving the accelerometer in the "+" direction, should i have a positive signal at the output of it (pin 30)? 
 When i' m pointing the accelerometer with the "+" sign to the ground (1g) i'm measuring 2.12 V 
 At 0g, i have 2.09V 
 With "+" pointing to the sky, i have 2.06V. 
 But, when i move the accelerometer in the direction of the "+", i'm measuring a negative pulse on the scope. 
 Moving in the "-" direction gives a positive one. 
 I,m very confused with this because we also use ST accelerometers (LIS344 for example) and their indications matches with the accelerometer motion (moving to the "+" gives a positive pulse. 
 Maybe i'm misinterpretating the datasheet? 
 Looking forward for your answer. 
 Best regards.

Yves · Accepted Answer

Hello Mark, 
 It's decreasing but positive. 
 The ADXL is supplied with 4.096V and so I have a DC output round 2.05V. 
 Thus, when I move to the accelerometer in the "+" direction, I should have more then 2.05V but in my case, it's less. 
 I do hope I'm clear enough. 
 Best regards. 
 Yves.)

Yves · Answer

Hello Mahdi, 
 Strangely on the ADXL377, when i point the arrow direction to the floor, it gives me a negative output. 
 To be clear, supplied by 3.3V, the midpoint is at 1.649V (0g), 1.655 at 1g and 1.642 at -1g (arrow to the floor).It's the contrary of the ADXL1001/1002. 
 I'm still a bit confused with this all. 
 Best regards.