question about calibration

[wjquigs11]

I just received my USFSMAX module and connected to an ESP32.
It does not seem to be able to calibrate. I slowly wave it around in circles in 3D for around 5 minutes, but "DHIC valid" never goes to 1, and R^2 remains zero.
I am in Seattle.
#ifdef SEATTLE_WA_USA #define M_V 49.2397f #define M_H 19.0403f #define MAG_DECLINIATION 15.0658f #endif

I have tried the default values as well as the 2D and 3D correctors, but I will be using the module on a boat so the 3D will be more useful.

Thanks for any assistance you can provide.

The image is after rotating in a slow circle.

[kriswiner]

Did you follow the description on how to do the DHIC here <https://github.com/gregtomasch/USFSMAX_MMC_Module#dynamic-hard-iron-dhi-correctors>? This should be straightforward but it does seem to confuse some. One thing to keep in mind is that the correction does not take effect until the next power cycle, as stated. Also, did you simply try to run the device as received without doing any corrections? It should be fairly accurate "out-of-the-box" unless you have horrendous hard iron distortions in your environment...

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On Mon, Apr 7, 2025 at 4:48 PM wjquigs11 ***@***.***> wrote: I just received my USFSMAX module and connected to an ESP32. It does not seem to be able to calibrate. I slowly wave it around in circles in 3D for around 5 minutes, but "DHIC valid" never goes to 1, and R^2 remains zero. I am in Seattle. #ifdef SEATTLE_WA_USA #define M_V 49.2397f #define M_H 19.0403f #define MAG_DECLINIATION 15.0658f #endif I have tried the default values as well as the 2D and 3D correctors, but I will be using the module on a boat so the 3D will be more useful. Thanks for any assistance you can provide. The image is after rotating in a slow circle. Screen.Shot.2025-04-07.at.4.28.35.PM.png (view on web) <https://github.com/user-attachments/assets/c3a22fd0-3084-4e77-87c2-6aec0f1b182b> Screen.Shot.2025-04-07.at.4.31.10.PM.png (view on web) <https://github.com/user-attachments/assets/f42dc58f-d873-4d6e-85dd-a21d50bdc7ad> — Reply to this email directly, view it on GitHub <#7>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABTDLKSBYBIHGFGE3S5E57L2YMFGPAVCNFSM6AAAAAB2U3ATNGVHI2DSMVQWIX3LMV43ASLTON2WKOZSHE3TQMRTGY4TMOI> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***> [image: wjquigs11]*wjquigs11* created an issue (gregtomasch/USFSMAX_MMC_Module#7) <#7> I just received my USFSMAX module and connected to an ESP32. It does not seem to be able to calibrate. I slowly wave it around in circles in 3D for around 5 minutes, but "DHIC valid" never goes to 1, and R^2 remains zero. I am in Seattle. #ifdef SEATTLE_WA_USA #define M_V 49.2397f #define M_H 19.0403f #define MAG_DECLINIATION 15.0658f #endif I have tried the default values as well as the 2D and 3D correctors, but I will be using the module on a boat so the 3D will be more useful. Thanks for any assistance you can provide. The image is after rotating in a slow circle. Screen.Shot.2025-04-07.at.4.28.35.PM.png (view on web) <https://github.com/user-attachments/assets/c3a22fd0-3084-4e77-87c2-6aec0f1b182b> Screen.Shot.2025-04-07.at.4.31.10.PM.png (view on web) <https://github.com/user-attachments/assets/f42dc58f-d873-4d6e-85dd-a21d50bdc7ad> — Reply to this email directly, view it on GitHub <#7>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABTDLKSBYBIHGFGE3S5E57L2YMFGPAVCNFSM6AAAAAB2U3ATNGVHI2DSMVQWIX3LMV43ASLTON2WKOZSHE3TQMRTGY4TMOI> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[wjquigs11]

Yes, initially I left ENABLE_DHI_CORRECTOR at 0 and rotated the sensor. This resulted in readings from approximately 240 to 270 degrees while turning through a circle. So I rebuilt, first with 3D, then I tried 2D (and rotated the sensor slowly in a circle on the table), then I tried 3D again. None of the tests resulted in anything but

Dynamic Hard Iron Correction Valid = 0

Dynamic Hard Iron Fit R-square = 0.0000

The ESP32 is a little under a meter from my laptop, and the sensor is around 30 cms from the ESP32. And it's all on my (wood) dining room table, so I doubt I have hard iron distortions.

The correction will only take effect if valid gets to 1, correct? Otherwise it will not overwrite eeprom correction values?

[kriswiner]

Something ain't right...I'll let Greg respond...he is the expert on DHIC.

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On Mon, Apr 7, 2025 at 5:55 PM wjquigs11 ***@***.***> wrote: Yes, initially I left ENABLE_DHI_CORRECTOR at 0 and rotated the sensor. This resulted in readings from approximately 240 to 270 degrees while turning through a circle. So I rebuilt, first with 3D, then I tried 2D (and rotated the sensor slowly in a circle on the table), then I tried 3D again. None of the tests resulted in anything but Dynamic Hard Iron Correction Valid = 0 Dynamic Hard Iron Fit R-square = 0.0000 The ESP32 is a little under a meter from my laptop, and the sensor is around 30 cms from the ESP32. And it's all on my (wood) dining room table, so I doubt I have hard iron distortions. The correction will only take effect if valid gets to 1, correct? Otherwise it will not overwrite eeprom correction values? — Reply to this email directly, view it on GitHub <#7 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABTDLKQK2KEV7M2F2AF6IVL2YMM6LAVCNFSM6AAAAAB2U3ATNGVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDOOBUHE3DKNRSHE> . You are receiving this because you commented.Message ID: ***@***.***> [image: wjquigs11]*wjquigs11* left a comment (gregtomasch/USFSMAX_MMC_Module#7) <#7 (comment)> Yes, initially I left ENABLE_DHI_CORRECTOR at 0 and rotated the sensor. This resulted in readings from approximately 240 to 270 degrees while turning through a circle. So I rebuilt, first with 3D, then I tried 2D (and rotated the sensor slowly in a circle on the table), then I tried 3D again. None of the tests resulted in anything but Dynamic Hard Iron Correction Valid = 0 Dynamic Hard Iron Fit R-square = 0.0000 The ESP32 is a little under a meter from my laptop, and the sensor is around 30 cms from the ESP32. And it's all on my (wood) dining room table, so I doubt I have hard iron distortions. The correction will only take effect if valid gets to 1, correct? Otherwise it will not overwrite eeprom correction values? — Reply to this email directly, view it on GitHub <#7 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABTDLKQK2KEV7M2F2AF6IVL2YMM6LAVCNFSM6AAAAAB2U3ATNGVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDOOBUHE3DKNRSHE> . You are receiving this because you commented.Message ID: ***@***.***>

[wjquigs11]

If it's useful, here's some output from Simple_Host_Utility:

`

Gyroscope Sensor Offsets (dps)

-1.0607

0.1698

1.5772

Gyroscope Calibration Tensor

1.0000,0.0000,0.0000

0.0000,1.0000,0.0000

0.0000,0.0000,1.0000

Accelerometer Sensor Offsets (g)

0.0057

-0.0149

0.0448

Accelerometer Calibration Tensor

0.9929,0.0039,0.0007

-0.0027,0.9931,-0.0073

-0.0067,0.0082,0.9927

Magnetometer Sensor Offsets (uT)

15.0490

-15.8146

-3.2815

Magnetometer Soft Iron Correction Tensor

1.0055,-0.0037,-0.0006

-0.0037,0.9990,-0.0027

-0.0006,-0.0027,0.9956

Magnetometer Residual Hard Iron Offsets (uT)

-0.0234

0.0303

0.0548

Magnetometer Fine Calibration/Alignment Tensor

1.0056,-0.0055,0.0106

0.0043,1.0066,-0.0080

-0.0110,0.0062,1.0052

Send '1' to continue...

Dynamic Hard Iron Correction Disabled!

ax = 274 ay = 940 az = 188 mg

gx = 2.0 gy = -0.2 gz = 0.3 deg/s

mx = -50.5 my = 46.7 mz = 57.1 uT

Tomasch Xh, Yh: -23.49, 73.46 uT

Baro pressure = 1004.71 hPa

USFSMAX Quat: q0 = 0.6943 qx = 0.6249 qy = 0.1002 qz = 0.3426

USFSMAX Yaw, Pitch, Roll: 267.44, 69.46, -55.46

hdg:267.4362

Sensor Acq Time:254 us

Accel scale = 1

Accel ODR = 7

Accel LPF = 2

Accel HPF = 0

Gyro scale = 12

Gyro ODR = 7

Gyro LPF = 2

Gyro HPF = 0

Quat div = 7

Mag scale = 0

Mag ODR = 4

Mag LPF = 0

Mag HPF = 0

Baro scale = 0

Baro ODR = 4

Baro LPF = 12

Baro HPF = 0

AUX_1 scale = 0

AUX_1 ODR = 0

AUX_1 LPF = 0

AUX_1 HPF = 0

AUX_2 scale = 0

AUX_2 ODR = 0

AUX_2 LPF = 0

AUX_2 HPF = 0

AUX_3 scale = 0

AUX_3 ODR = 0

AUX_3 LPF = 0

AUX_3 HPF = 0

Vert FS = 49.23970

Horiz FS = 19.04030

Declination = 15.06580

Cal points = 2048

Send '1' to continue...
`

[kriswiner]

Greg will respond in more detail, I will just note that this: ax = 274 ay = 940 az = 188 mg gx = 2.0 gy = -0.2 gz = 0.3 deg/s mx = -50.5 my = 46.7 mz = 57.1 uT seems way off. Forget about the mag for a moment, unless you are waving this around while collecting this data, the accel should show a few mg on x and y axes and ~1000 mg on z while the gyro should show a few mdeg/s on all axes, or 0.0 deg/s for gx, gy, and gz when the sensor is laying flat and motionless. For the mag, the scalar field should be about ~0.5 Gauss or 50 uT...you are showing ~85 uT or about 1.7 x this expected value...not sure what the heck is going on with this data, don't make no sense....

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On Mon, Apr 7, 2025 at 6:17 PM wjquigs11 ***@***.***> wrote: If it's useful, here's some output from Simple_Host_Utility: ` Gyroscope Sensor Offsets (dps) -1.0607 0.1698 1.5772 Gyroscope Calibration Tensor 1.0000,0.0000,0.0000 0.0000,1.0000,0.0000 0.0000,0.0000,1.0000 Accelerometer Sensor Offsets (g) 0.0057 -0.0149 0.0448 Accelerometer Calibration Tensor 0.9929,0.0039,0.0007 -0.0027,0.9931,-0.0073 -0.0067,0.0082,0.9927 Magnetometer Sensor Offsets (uT) 15.0490 -15.8146 -3.2815 Magnetometer Soft Iron Correction Tensor 1.0055,-0.0037,-0.0006 -0.0037,0.9990,-0.0027 -0.0006,-0.0027,0.9956 Magnetometer Residual Hard Iron Offsets (uT) -0.0234 0.0303 0.0548 Magnetometer Fine Calibration/Alignment Tensor 1.0056,-0.0055,0.0106 0.0043,1.0066,-0.0080 -0.0110,0.0062,1.0052 Send '1' to continue... Dynamic Hard Iron Correction Disabled! ax = 274 ay = 940 az = 188 mg gx = 2.0 gy = -0.2 gz = 0.3 deg/s mx = -50.5 my = 46.7 mz = 57.1 uT Tomasch Xh, Yh: -23.49, 73.46 uT Baro pressure = 1004.71 hPa USFSMAX Quat: q0 = 0.6943 qx = 0.6249 qy = 0.1002 qz = 0.3426 USFSMAX Yaw, Pitch, Roll: 267.44, 69.46, -55.46 hdg:267.4362 Sensor Acq Time:254 us Accel scale = 1 Accel ODR = 7 Accel LPF = 2 Accel HPF = 0 Gyro scale = 12 Gyro ODR = 7 Gyro LPF = 2 Gyro HPF = 0 Quat div = 7 Mag scale = 0 Mag ODR = 4 Mag LPF = 0 Mag HPF = 0 Baro scale = 0 Baro ODR = 4 Baro LPF = 12 Baro HPF = 0 AUX_1 scale = 0 AUX_1 ODR = 0 AUX_1 LPF = 0 AUX_1 HPF = 0 AUX_2 scale = 0 AUX_2 ODR = 0 AUX_2 LPF = 0 AUX_2 HPF = 0 AUX_3 scale = 0 AUX_3 ODR = 0 AUX_3 LPF = 0 AUX_3 HPF = 0 Vert FS = 49.23970 Horiz FS = 19.04030 Declination = 15.06580 Cal points = 2048 Send '1' to continue... ` — Reply to this email directly, view it on GitHub <#7 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABTDLKVCCCJTR4QEFHJS7O32YMPSXAVCNFSM6AAAAAB2U3ATNGVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDOOBUHE4TAMJRGY> . You are receiving this because you commented.Message ID: ***@***.***> [image: wjquigs11]*wjquigs11* left a comment (gregtomasch/USFSMAX_MMC_Module#7) <#7 (comment)> If it's useful, here's some output from Simple_Host_Utility: ` Gyroscope Sensor Offsets (dps) -1.0607 0.1698 1.5772 Gyroscope Calibration Tensor 1.0000,0.0000,0.0000 0.0000,1.0000,0.0000 0.0000,0.0000,1.0000 Accelerometer Sensor Offsets (g) 0.0057 -0.0149 0.0448 Accelerometer Calibration Tensor 0.9929,0.0039,0.0007 -0.0027,0.9931,-0.0073 -0.0067,0.0082,0.9927 Magnetometer Sensor Offsets (uT) 15.0490 -15.8146 -3.2815 Magnetometer Soft Iron Correction Tensor 1.0055,-0.0037,-0.0006 -0.0037,0.9990,-0.0027 -0.0006,-0.0027,0.9956 Magnetometer Residual Hard Iron Offsets (uT) -0.0234 0.0303 0.0548 Magnetometer Fine Calibration/Alignment Tensor 1.0056,-0.0055,0.0106 0.0043,1.0066,-0.0080 -0.0110,0.0062,1.0052 Send '1' to continue... Dynamic Hard Iron Correction Disabled! ax = 274 ay = 940 az = 188 mg gx = 2.0 gy = -0.2 gz = 0.3 deg/s mx = -50.5 my = 46.7 mz = 57.1 uT Tomasch Xh, Yh: -23.49, 73.46 uT Baro pressure = 1004.71 hPa USFSMAX Quat: q0 = 0.6943 qx = 0.6249 qy = 0.1002 qz = 0.3426 USFSMAX Yaw, Pitch, Roll: 267.44, 69.46, -55.46 hdg:267.4362 Sensor Acq Time:254 us Accel scale = 1 Accel ODR = 7 Accel LPF = 2 Accel HPF = 0 Gyro scale = 12 Gyro ODR = 7 Gyro LPF = 2 Gyro HPF = 0 Quat div = 7 Mag scale = 0 Mag ODR = 4 Mag LPF = 0 Mag HPF = 0 Baro scale = 0 Baro ODR = 4 Baro LPF = 12 Baro HPF = 0 AUX_1 scale = 0 AUX_1 ODR = 0 AUX_1 LPF = 0 AUX_1 HPF = 0 AUX_2 scale = 0 AUX_2 ODR = 0 AUX_2 LPF = 0 AUX_2 HPF = 0 AUX_3 scale = 0 AUX_3 ODR = 0 AUX_3 LPF = 0 AUX_3 HPF = 0 Vert FS = 49.23970 Horiz FS = 19.04030 Declination = 15.06580 Cal points = 2048 Send '1' to continue... ` — Reply to this email directly, view it on GitHub <#7 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABTDLKVCCCJTR4QEFHJS7O32YMPSXAVCNFSM6AAAAAB2U3ATNGVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDOOBUHE4TAMJRGY> . You are receiving this because you commented.Message ID: ***@***.***>

[gregtomasch]

The first thing I notice is high residual gyroscope values. the first thing to try is to set the unit down motionless and do the gyroscope calibration.

Otherwise, the slow rotation test you show in the attached graphic looks horrendous. I suspect a gross level of stray fields. can you send a photo of the physical implementation of your ESP32 and USFSMAX?

[wjquigs11]

It was probably in motion for those readings. When it's sitting on the table, I get these readings (the accelerometer at least looks "normal", close to 1G ax because it's not lying flat).

Swinging in a circle on the table I get this:

Here's the setup:

[wjquigs11]

I also tried this. There seems to be a tiny amount of ferrous metal in the test leads. Enough to cause the issue?

[wjquigs11]

Still struggling to get good data from this module. Some of the things I've tried:

• twisting pairs of leads to module
• different ESP32
• removed module, soldered pin headers to carrier, replaced module, and rewired
• compiled with Madgwick instead of Mahony
• reduced data rate on magnetometer to 10Hz
• changed location to Yuba City since that's the closest predefined location
• even tried compiling for Arduino to remove possible antenna interference (although wifi and BT are not enabled)

Same results; heading ranges from 100 to 155 degrees when rotating in a slow circle on the table.
The accelerometer and gyro readings look normal: 1G when sitting on the table, and gyro output is as expected when I tilt the breadboard in each axis. It seems to be the magnetometer that's causing the problem.

Would appreciate any input.

[kriswiner]

Please send me an e-mail to ***@***.*** and we will help you diagnose the problem. I don't quite understand compiling with Madgwick or Mahony...neither of these is used in the USFSMAX module firmware...so it could be you are simply looking at the wrong output... Please e-mail so Grag and I can understand what is going wrong and help you fix it. Thanks, Kris

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On Sat, Apr 12, 2025 at 8:48 AM wjquigs11 ***@***.***> wrote: Still struggling to get good data from this module. Some of the things I've tried: - twisting pairs of leads to module - different ESP32 - removed module, soldered pin headers to carrier, replaced module, and rewired - compiled with Madgwick instead of Mahony - reduced data rate on magnetometer to 10Hz - changed location to Yuba City since that's the closest predefined location - even tried compiling for Arduino to remove possible antenna interference (although wifi and BT are not enabled) Same results; heading ranges from 100 to 155 degrees when rotating in a slow circle on the table. The accelerometer and gyro readings look normal: 1G when sitting on the table, and gyro output is as expected when I tilt the breadboard in each axis. It seems to be the magnetometer that's causing the problem. Would appreciate any input. — Reply to this email directly, view it on GitHub <#7 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABTDLKVHHQEUHRX5QL7NOVT2ZEYVDAVCNFSM6AAAAAB2U3ATNGVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDOOJYHA4DEMZRGE> . You are receiving this because you commented.Message ID: ***@***.***> *wjquigs11* left a comment (gregtomasch/USFSMAX_MMC_Module#7) <#7 (comment)> Still struggling to get good data from this module. Some of the things I've tried: - twisting pairs of leads to module - different ESP32 - removed module, soldered pin headers to carrier, replaced module, and rewired - compiled with Madgwick instead of Mahony - reduced data rate on magnetometer to 10Hz - changed location to Yuba City since that's the closest predefined location - even tried compiling for Arduino to remove possible antenna interference (although wifi and BT are not enabled) Same results; heading ranges from 100 to 155 degrees when rotating in a slow circle on the table. The accelerometer and gyro readings look normal: 1G when sitting on the table, and gyro output is as expected when I tilt the breadboard in each axis. It seems to be the magnetometer that's causing the problem. Would appreciate any input. — Reply to this email directly, view it on GitHub <#7 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABTDLKVHHQEUHRX5QL7NOVT2ZEYVDAVCNFSM6AAAAAB2U3ATNGVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDOOJYHA4DEMZRGE> . You are receiving this because you commented.Message ID: ***@***.***>

[wjquigs11]

Hi Kris, github is filtering your email address.

[wjquigs11]

Should I use t l e r a c o r p...?

[kriswiner]

***@***.*** but lower case

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On Sat, Apr 12, 2025 at 9:00 AM wjquigs11 ***@***.***> wrote: Should I use t l e r a c o r p...? — Reply to this email directly, view it on GitHub <#7 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABTDLKQRIBL4JAZVWTLQDSL2ZE2AXAVCNFSM6AAAAAB2U3ATNGVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDOOJYHA4DMMRUHA> . You are receiving this because you commented.Message ID: ***@***.***> *wjquigs11* left a comment (gregtomasch/USFSMAX_MMC_Module#7) <#7 (comment)> Should I use t l e r a c o r p...? — Reply to this email directly, view it on GitHub <#7 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABTDLKQRIBL4JAZVWTLQDSL2ZE2AXAVCNFSM6AAAAAB2U3ATNGVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDOOJYHA4DMMRUHA> . You are receiving this because you commented.Message ID: ***@***.***>

[kriswiner]

Forget about github, just send me an e0mail. On Sat, Apr 12, 2025 at 9:00 AM Tlera Corporation ***@***.***> wrote:

…

***@***.*** but lower case On Sat, Apr 12, 2025 at 9:00 AM wjquigs11 ***@***.***> wrote: > Should I use t l e r a c o r p...? > > — > Reply to this email directly, view it on GitHub > <#7 (comment)>, > or unsubscribe > <https://github.com/notifications/unsubscribe-auth/ABTDLKQRIBL4JAZVWTLQDSL2ZE2AXAVCNFSM6AAAAAB2U3ATNGVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDOOJYHA4DMMRUHA> > . > You are receiving this because you commented.Message ID: > ***@***.***> > *wjquigs11* left a comment (gregtomasch/USFSMAX_MMC_Module#7) > <#7 (comment)> > > Should I use t l e r a c o r p...? > > — > Reply to this email directly, view it on GitHub > <#7 (comment)>, > or unsubscribe > <https://github.com/notifications/unsubscribe-auth/ABTDLKQRIBL4JAZVWTLQDSL2ZE2AXAVCNFSM6AAAAAB2U3ATNGVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDOOJYHA4DMMRUHA> > . > You are receiving this because you commented.Message ID: > ***@***.***> >