[CLOSED] Problem with IMU?

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tobias
Bitcraze
Posts: 2339
Joined: Mon Jan 28, 2013 7:17 pm
Location: Sweden

Re: (Hopefully not) Problem with IMU?

Post by tobias »

If you have access to a hot-air reflow station that is the first thing I would try, to reflow the chip again. It could be a broken sensor but we have seen very few, higher probability that it is a soldering that has cracked. Try pushing your finger against the chip when you start the test software, that could reveal a bad connection.
Call_me_a_Cab
Member
Posts: 51
Joined: Wed Dec 17, 2014 12:56 pm

Re: (Hopefully not) Problem with IMU?

Post by Call_me_a_Cab »

Hi Guys got a problem here.

SYS: ----------------------------
SYS: Crazyflie is up and running!
SYS: Build 9+:a21fee8ae81d (2014.12.0) MODIFIED
0029 and I have 1024KB of flash!
IMU: MPU9250 I2C connection [FAIL].
IMU: AK8963 I2C connection [OK].
IMU: LPS25H I2C connection [OK].
EXPBRD: Found 1 memories.
EXPBRD: Info board 0:
-Header:EB
-Pins :0x8000
-Vid :BC
-Pid :1
-crc :23
EEPROM: I2C connection [OK].
AK8963: Self test [OK].
LPS25H: Self test [OK].
OW: Found 1.
OW: Serial 0xD 91 7A 8 0 0 0 72.
SYS: Free heap: 5872 bytes
EB 0 80 0 0 BC 1 23 0 E 1
Status 0
0 E 1 9 62 63 4C 65 64 52 69 6E 67 2 1 42 9D
Status 0
30 78 42 43 0 50 0 0 0 0 0 0 0 0 0 7D
Status 0
EB 0 80 0 0 BC 1 23 0 E 1
Status 0
EB 0 80 0 0 BC 1 23 0 E 1
Status 0
E 67 2 1 42 9D
Status 0
0 E 1 9 62 63 4C 65 64 52 69 6E 67 2 1 42 9D
Status 0
30 78 42 43 0 50 0 0 0 0 0 0 0 0 0 7D
Status 0
EB 0 80 0 0 BC 1 23 0 E 1
Status 0
EB 0 80 0 0 BC 1 23 0 E 1
Status 0
0 E 1 9 62 63 4C 65 64 52 69 6E 67 2 1 42 9D
Status 0
Call_me_a_Cab
Member
Posts: 51
Joined: Wed Dec 17, 2014 12:56 pm

Re: (Hopefully not) Problem with IMU?

Post by Call_me_a_Cab »

I now have this with Stock firmware and IMU test loaded

SYS: Build 6+:29624e7f6e3b (2014.12.0) MODIFIED
SYS: I am 0x3132383231334712240029 and I have 1024KB of flash!
IMU: MPU9250 I2C connection [OK].
IMU: AK8963 I2C connection [OK].
IMU: LPS25H I2C connection [OK].
EXPBRD: Found 1 memories.
EXPBRD: Info board 0:
-Header:EB
-Pins :0x8000
-Vid :BC
-Pid :1
-crc :23
EEPROM: I2C connection [OK].
MPU6500: Self test [OK].
IMU: Gyro variance test [OK]
IMU: Acc level test [OK]
AK8963: Self test [OK].
LPS25H: Self test [OK].
OW: Found 1.
OW: Serial 0xD 91 7A 8 0 0 0 72.
SYS: Free heap: 5872 bytes
EB 0 80 0 0 BC 1 23 0 E 1
Status 0
0 E 1 9 62 63 4C 65 64 52 69 6E 67 2 1 42 9D
Status 0
EB 0 80 0 0 BC 1 23 0 E 1
Status 0
0 E 1 9 62 63 4C 65 64 52 69 6E 67 2 1 42 9D
Status 0
EB 0 80 0 0 BC 1 23 0 E 1
Status 0
OW: Cmd 0x22 timeout.
B8 3A 1 23 0 E 1 9 62 63 4C 65 64 52 69 6E 67
Status 5
0 E 1 9 62 63 4C 65 64 52 69 6E 67 2 1 42 9D
Status 0
OW: Cmd 0x22 timeout.
B8 3A 4C 65 64 52 69 6E 67 2 1 42 9D AA 55 55 AA
Status 5
0 E 1 9 62 63 4C 65 64 52 69 6E 67 2 1 42 9D
Status 0
30 78 42 43 0 50 0 0 0 0 0 0 0 0 0 7D
Status 0
30 78 42 43 0 50 0 0 0 0 0 0 0 0 0 7D
Status 0
tobias
Bitcraze
Posts: 2339
Joined: Mon Jan 28, 2013 7:17 pm
Location: Sweden

Re: (Hopefully not) Problem with IMU?

Post by tobias »

IMU: MPU9250 I2C connection [FAIL].
This is a bit strange since you don't get the "I2CDEV: Error callback nr: 1024" as in this post. And you never got it with the IMU test firmware?
Call_me_a_Cab
Member
Posts: 51
Joined: Wed Dec 17, 2014 12:56 pm

Re: (Hopefully not) Problem with IMU?

Post by Call_me_a_Cab »

Tobias,

To be honest I'm a bit lost. I've had a few different firmwares in there and all are giving weird results.

basically I was running with the latest Git firmware (modified by me to enable LED effect zero as default) and whilst flying the CF flipped and the IMU went crazy.

After this I flashed the test firmware and it was ok but again after a short while it started flipping again.

Sometimes it works, sometimes it doesn't. the latest fail I have seen is:

SYS: Crazyflie is up and running!
SYS: Build 6+:29624e7f6e3b (2014.12.0) MODIFIED
SYS: I am 0x313238323133471224h!
IMU: MPU9250 I2C connection [OK].
IMU: AK8963 I2C connection [OK].
IMU: LPS25H I2C connection [OK].
EXPBRD: Found 0 memories.
EEPROM: I2C connection [OK].
MPU6500: Self test acc X [FAIL]. low: -14.0, high: 14.0, measured: -2147483647.2147483647
OW: Found 0.
30 78 42 43 0 50 0 0 0 0 0 0 0 0 0 7D
Status 0
30 78 42 43 0 50 0 0 0 0 0 0 0 0 0 7D
Status 0


At this point I've lost the plot and don't even remember which firmware this was.
tobias
Bitcraze
Posts: 2339
Joined: Mon Jan 28, 2013 7:17 pm
Location: Sweden

Re: (Hopefully not) Problem with IMU?

Post by tobias »

It sounds a lot like a bad connection as well, probably a cracked solder. Try pushing your finger against the chip when you start the test software, that could reveal a bad connection. The sensor chip is the small chip on the top side in the center line beside the big chip.
Call_me_a_Cab
Member
Posts: 51
Joined: Wed Dec 17, 2014 12:56 pm

Re: (Hopefully not) Problem with IMU?

Post by Call_me_a_Cab »

Pushing my finger doesnt help :(

I just got it flying after re flashing the latest git firmware plus my 0 effect change.

Flew for about 20 secs the flipped.

Console:


ng!
SYS: Build 9+:a21fee8ae81d (2014.12.0) MODIFIED
SYS: I am 0x3132383231334712240029 and I have 1024KB of flash!
IMU: MPU9250 I2C connection [OK].
IMU: AK8963 I2C connection [OK].
IMU: LPS25H I2C connection [OK].
EXPBRD: Found 1 memories.
EXPBRD: Info board 0:
-Header:EB
-Pins :0x8000
-Vid :BC
-Pid :1
-crc :23
EEPROM: I2C connection [OK].
AK8963: Self test [OK].
LPS25H: Self test [OK].
OW: Found 1.
OW: Serial 0xD 91 7A 8 0 0 0 72.
SYS: Free heap: 5872 bytes
EB 0 80 0 0 BC 1 23 0 E 1
Status 0
0 E 1 9 62 63 4C 65 64 52 69 6E 67 2 1 42 9D
Status 0
EB 0 80 0 0 BC 1 23 0 E 1
Status 0
0 E 1 9 62 63 4C 65 64 52 69 6E 67 2 1 42 9D
Status 0
OW: Cmd 0x22 timeout.
B8 3A 0 0 0 0 0 0 67 2 1
Status 5
0 E 1 9 62 63 4C 65 64 52 69 6E 67 2 1 42 9D
Status 0
30 78 42 43 0 50 0 0 0 0 0 0 0 0 0 7D
Status 0
30 78 42 43 0 50 0 0 0 0 0 0 0 0 0 7D
Status 0
30 78 42 43 0 50 0 CD CC CC 3E 66 66 A6 BF 51
Status 0
30 78 42 43 0 50 0 CD CC CC 3E 66 66 A6 BF 51
Status 0
I2CDEV: Error callback nr: 1024
I2CDEV: Error callback nr: 1024
tobias
Bitcraze
Posts: 2339
Joined: Mon Jan 28, 2013 7:17 pm
Location: Sweden

Re: (Hopefully not) Problem with IMU?

Post by tobias »

Something definitely happens to the sensor chip. My best guess is that is a cracked soldering and to check that the chip needs to be reflowed (solder melted). It can be done with a normal heat gun but other parts need to be heat protected. I will try to find some time and shoot a video of it during the week.
Call_me_a_Cab
Member
Posts: 51
Joined: Wed Dec 17, 2014 12:56 pm

Re: (Hopefully not) Problem with IMU?

Post by Call_me_a_Cab »

Ok Great,

We have a heat gun and thermal insulation tape at work. I will youtube it. Should I expect to see any "bubbling" or other signs when heating the chip?
tobias
Bitcraze
Posts: 2339
Joined: Mon Jan 28, 2013 7:17 pm
Location: Sweden

Re: (Hopefully not) Problem with IMU?

Post by tobias »

Actually some aluminium foil covering the board with a small hole around the chip would work well. It is the expansion port and battery connector that are the most heat sensitive.

The difficulty can be to see when the solder has melted. It tend to become a little bit more shiny but it can be hard to see. Another option is to give the chip very small nudges with a tweezers to see when it starts "floating". That it has all melted. The difficulty can be not to nudge it out of place, with a bit of carefulness it shouldn't be a problem though. There should be plenty of videos on youtube, I'll check if I can find any.
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