the ADXL 345 accelerometer seems common enough, plenty of threads on this forum here, but a search of "GY-291" turns up only one thread in Spanish.
on the internet "GY-291" results in accelerometer modules (i think they're all from China) and i see they all use the ADXL 345 chip.
am wondering if anybody knows what the difference is; is the GY-291 code just to indicate the modules that are coming out of China, they all seem to be in blue.
the price difference is quite marked too - there doesn't seem to be much difference in the specs,
this from dx.com;GY-291
= US$ 7.29
Chipset: ADXL345; Power supply :3~5V; Communication methods: the IIC/SPI communication protocol; Measuring range: +/- 2g +/-16g; 3-Axis, +/- 2g; +/-4g; +/-8g; +/- 16g
and this from SparkFun;ADXL-345
2.0-3.6VDC Supply Voltage
Ultra Low Power: 40uA in measurement mode, 0.1uA in standby@ 2.5V
Tap/Double Tap Detection
SPI and I2C interfaces
would those extra Detection features be one reason for the price difference ?
the more expensive board has LESS components on it... :-/