SparkFun Forums

[Laurenceb]

I have a MLX90609 from sparkfun (+-75 degrees/sec on breakout board) which appears to be malfunctioning, the ADC output is hovering around 920 to 940. The gyro was working nicely on arrival, and I managed to obtain good heading data. However, during a cooldown test to -21c (peltier cooler) the output went off to a 920 to 940 ADC output, and was unresponsive. This disappeared after the power was disconnected and the reconnected around 15 seconds later.
The problem has not reappeared, and is continuous. Upon further investigation I find that the ERR pin is high, Selftest pin is high, current into VCC is 16.2ma, and the analogue rate output is 2.30V. It was suggested to me that condensation formed during the cooldown test, but the gyro was securely wrapped in insulating tape. It also seems highly unlikely that the gyro could have been fried, antistatic precautions were taken at all times. I have tried a variety of power supplies with no luck.
Can anyone suggest anything? What is sparkfuns return policy? I have the data recorded during the cooldown test if that helps "prove my case". It would be extremely dissapointing if the gyro is broken, as it looked very encouraging before the problem appeared, keeping a heading to +-10 degrees over several minutes.

Laurence

[juanpablocanguro]

Same thing happened to me! I ordered 2 MLX90609 the 150°deg/sec version, hooked one of them up, worked fine lasta night, today as I was testing it suddenly the reading went to 391 and stayed there for quite a while, I replaced it for the other one and that one worked!!! then as I was trying to realize what had happened the first one started working again... and then it stopped. Replaced it with the other one again but this time it also got stuck at 0 reading, it does obey when I send the command to change the channel to the Temp sensor and that one reads ok, but the gyro channel reads zero! then as I was resoldering and checking for faulty solders, the heat seemed to make it work for a while again but as it cooled it stoped working. Temperature here is 22°C.

Whats going on with these sensors? are they defective? I think I want my money back

[Laurenceb]

Hi there, Get in touch and you should be able to return the gyro. I did, but they were unable to identify the fault, so its been returned . I've now got a second +-150 degree/sec gyro thats working fine . I believe it may be a quality control issue with melexis, I cant think there would be a fault with the design or they wouldnt be selling it. I would be tempted to try something else, but the mlx90609 has amazing temperature stability, which is vital for my project. If your looking for something cheap but without the exceptional temperature stability, try the new analogue devices gyros with spi, or a nintendo motion card.