I'm playing with a GT-25 board, which is basically a 6050 accelerometer/gyroscope sensor with an onboard MCU. The MCU takes care of handling the 6050 and can talk to an Arduino via a serial link. I'm using the basic code from Angle range of Gy-25 sensor and it works in that I get roll, tilt and yaw readout in degrees. Very simple and easy to use interface.
However I'm seeing an irregularly spaced "sawtooth" type wave form, especially prominant on the roll axis, but detectable on yaw and still there slightly on pitch.
Anyone else see anything like this. The GY-25 is, of course, from China, so all bets are off when it comes to quality control. There are also a number of things I'm not sure about in the "documentation" (such as it is).
(1) Does the board self calibrate every time it is powered up?
(2) what exactly do the 0x54 and 0x55 commands do? I think 0x54 may reset roll to zero and 0x55 may set yaw to zero, but I'm not sure. There appears to be no instruction to set pitch to zero (unless that's power on)
(3) what exactly can the I2C interface do? There are two connections (normally open) which can be shorted. Open is "I2C towards 6050", shorted is "I2C towards output". Does this means that you can talk directly to the 6050 via I2C is the connections are open, but if they are shorted then you can replace the serial connection with an I2C connection?
If anyone has played around with the GT-25 I'd be interested what they found, especially concerning the "sawtooth" behavior I'm seeing on the output values. It can't be normal and there are only a few serial commends it understands, none of which would deal this
You might get some help if you post your schematic, not a frizzy thing along with your code and some links to the technical information on the hardware items.
Hi, I have a very recent bad experience with MPU6050 bought in China also.
I bought a set of 4 MPU6050 accel/gyro sensors. The first hour, a first sensor died after having melt its VDD/GND connectors.
With the 3 other sensors, I was unable to make converging any calibration sketchs (3 differents sketches used), even after hours of execution, sensors perfectly still, glued on a spirit level. raw measurements did not show any unstability or weird behavior as yours. At maximum, 4 of the 6 axis manage to get calibrated (Modified sketch to visualize it).
Yesterday, I'v receveid 2 other sensors (bought also in Alixxxx, China), and for these 2 one, calibration was done in a twinkling of an eye.
--> Quality issues in batches of sensors.
Hoping it can give your an hint ! If I were you, I would I buy another sensor in China also but on a different resaler/date to compare. Not a big issue, they are very cheap.
There are some odd "6050" boards out there. You may find that the ones which do not calibrate have a chip marked 6050A and/or they give a 0x98 response to the "Who_on_1" request rather then the expected 0x68. See a previous post of mine at MPU 6050(A) module problems - WHO_AM_I reports 0x98, not 0x68 as it should. Fake MPU 6050. The odd thing is that these chips will run code for the accelerometers if you tweak the sketch so that 0x98 is an acceptable answer to the "who_am-I" request and use the default calibration data. This is odd because if the chip is really a ICM-20689 (as suggested in my earlier post), the data registers for the accelerometer data should be in a different place - but it appears they aren't. They appear to be in the right place for a 6050.
The GY-25 board has a 6050 on it (not a 6050A), so I have no idea what's going on. The boards from China are cheap enough to just throw away if they don't work. I think the trick may be to do that rather then try to figure out why they don't work! I've given up on the GY-25 I think. Not worth wasting my time on it.
