Author Topic: Hacking the Siglent SDM3055 Bench DMM  (Read 4192 times)

alexvg, SimonD and 1 Guest are viewing this topic.

Online alexvg

  • Regular Contributor
  • *
  • Posts: 78
  • Country: fr
Hacking the Siglent SDM3055 Bench DMM
« on: August 10, 2019, 12:37:52 am »


During my SDM3055 reverse engineering... I've got 2 questions to you ?

Would you agree to pay a small amount for a new SDM3055 software (and maybe for the SDM3045) ?
http://www.pixule.com/39863606081_would-you-agree-to-pay-small-amount-for-new-sdm3055-software-and-maybe-for-the-sdm3045.html

Would you like to improve your SDM3055 by adding a some options ? (The SDM3045 may be compatible with these options.)
http://www.pixule.com/398636486944_would-you-like-to-improve-your-sdm3055-by-adding-some-options.html

Thanks for your help !



Hi,

I'm working on a hack to show more digit to the Siglent SDM3055
I've got a source voltage of 2.5V (not a reference voltage)

Original : 240 000 points / 5 1/2 digits


First hack result : 2 400 000 points / 6 1/2 digits


The hack does not work correctly but give interresting result.
To be continued.
« Last Edit: August 19, 2019, 07:28:28 pm by alexvg »
 
The following users thanked this post: thm_w, tv84, kj7e, BillB, joeyjoejoe

Offline tv84

  • Frequent Contributor
  • **
  • Posts: 797
  • Country: pt
Re: Hacking the Siglent SDM3055 Bench DMM
« Reply #1 on: August 10, 2019, 08:55:24 am »
 :clap:

Alexia, as requested. 2 of the latest app versions attached. Good luck!
« Last Edit: August 10, 2019, 04:16:04 pm by tv84 »
 

Online alexvg

  • Regular Contributor
  • *
  • Posts: 78
  • Country: fr
Re: Hacking the Siglent SDM3055 Bench DMM
« Reply #2 on: August 11, 2019, 11:59:47 pm »
New results with 7.5 digits
The calibration data are not currently loaded :



 

Offline Mr. Scram

  • Super Contributor
  • ***
  • Posts: 7721
  • Country: 00
  • Display aficionado
Re: Hacking the Siglent SDM3055 Bench DMM
« Reply #3 on: August 12, 2019, 12:12:33 am »
Nice experiment! Not to rain on your parade, but are these numbers relevant? Do we know whether the 6.5 digit versions maybe have cherry picked or simply better references? I'm asking because many meters can show more digits but it's generally noise. Don't let it discourage you though and be sure to hack on!
 

Online alexvg

  • Regular Contributor
  • *
  • Posts: 78
  • Country: fr
Re: Hacking the Siglent SDM3055 Bench DMM
« Reply #4 on: August 12, 2019, 12:23:57 am »
I've noticed some mistake into the code :
A real value of 1.499995 is displayed 1.4999 instead of 1.5000.

But a value of 1.4999995 is displayed 1.5000. It's because the rounding is done with a value of 5.0x10-7


« Last Edit: August 12, 2019, 12:25:58 am by alexvg »
 

Offline coromonadalix

  • Super Contributor
  • ***
  • Posts: 2016
  • Country: ca
Re: Hacking the Siglent SDM3055 Bench DMM
« Reply #5 on: August 12, 2019, 12:46:22 am »
I would love to see this hack against a AC / DC / Ohms  calibrator ??
 

Offline tautech

  • Super Contributor
  • ***
  • Posts: 15745
  • Country: nz
  • Taupaki Technologies Ltd. NZ Siglent Distributor
    • Taupaki Technologies Ltd.
Re: Hacking the Siglent SDM3055 Bench DMM
« Reply #6 on: August 12, 2019, 01:40:40 am »
Not to rain on your parade, but are these numbers relevant? Do we know whether the 6.5 digit versions maybe have cherry picked or simply better references?
Yes of course measurement stability can be questioned as SDM3065X uses the better LM399 reference.

Avid Rabid Hobbyist
 

Offline coromonadalix

  • Super Contributor
  • ***
  • Posts: 2016
  • Country: ca
Re: Hacking the Siglent SDM3055 Bench DMM
« Reply #7 on: August 12, 2019, 07:26:30 am »
Could the 3065 and 3055  share the same design, minus the reference quality ?? 

Q: The hacked firmware, does it come from the 3065 ??
 

Offline tautech

  • Super Contributor
  • ***
  • Posts: 15745
  • Country: nz
  • Taupaki Technologies Ltd. NZ Siglent Distributor
    • Taupaki Technologies Ltd.
Re: Hacking the Siglent SDM3055 Bench DMM
« Reply #8 on: August 12, 2019, 08:20:52 am »
Images from SDM3000 series thread
https://www.eevblog.com/forum/testgear/siglent-new-bench-dmm-sdm3055/

SDM3045X


SDM3055


SDM3065X
Avid Rabid Hobbyist
 
The following users thanked this post: coromonadalix

Online alexvg

  • Regular Contributor
  • *
  • Posts: 78
  • Country: fr
Re: Hacking the Siglent SDM3055 Bench DMM
« Reply #9 on: August 12, 2019, 08:56:31 am »
Could the 3065 and 3055  share the same design, minus the reference quality ?? 
The SDM3065X uses a LM399H (0.3ppm/C with 20ppm/1000h and 7uV noise) voltage reference and AD7175-2 "B" A/D (up to 24 peak-to-peak bits and 24 effective bits at 5 to 16 SPS).
The SDM3055 uses a MAX6325 "C" (0.5ppm/C with 30ppm/1000h and 1.3uV noise) voltage reference and AD7190 "B" A/D (up to 22.5 peak-to-peak bits and 24 effective bits at 4.7 SPS).
The SDM3045X uses TI REF5025K "High grade" (2.5ppm/C with 100ppm/1000h and 3uV noise ) and AD7190 "B" A/D (up to 22.5 peak-to-peak bits and 24 effective bits at 4.7 SPS).

Edit 2019-08-18
Difference vs SDM3055 :
- SDM3065X uses a separate power supply
- SDM3065X uses a LM399H voltage reference and a higher resolution ADC
- SDM3045X uses lower grade components but with a SDM3055 design (or SDM3055X-E PCB)

I suspect the SDM3055 could have a better ADC (see un populated U503 SSOP28) like ADS1256 (seems to be compatible)



Q: The hacked firmware, does it come from the 3065 ??
I'm only using the original SDM3055 firmware.
« Last Edit: August 18, 2019, 10:08:44 pm by alexvg »
 

Offline tv84

  • Frequent Contributor
  • **
  • Posts: 797
  • Country: pt
Re: Hacking the Siglent SDM3055 Bench DMM
« Reply #10 on: August 12, 2019, 09:10:28 am »
If anyone with a 3045X wants to test the 3055 in his DMM, I can easily prepare an .ADS.

BUT, no responsibility for my side.
 

Offline tautech

  • Super Contributor
  • ***
  • Posts: 15745
  • Country: nz
  • Taupaki Technologies Ltd. NZ Siglent Distributor
    • Taupaki Technologies Ltd.
Re: Hacking the Siglent SDM3055 Bench DMM
« Reply #11 on: August 12, 2019, 11:34:16 am »
I'm working on a hack to show more digit to the Siglent SDM3055

To be continued.....................
And he busted it !  :palm:

PM pleading for help ...............
And returned.
Avid Rabid Hobbyist
 

Offline BillB

  • Frequent Contributor
  • **
  • Posts: 545
  • Country: us
Re: Hacking the Siglent SDM3055 Bench DMM
« Reply #12 on: August 12, 2019, 12:12:52 pm »
Well, that escalated quickly!   ???
 

Online alexvg

  • Regular Contributor
  • *
  • Posts: 78
  • Country: fr
Re: Hacking the Siglent SDM3055 Bench DMM
« Reply #13 on: August 12, 2019, 01:36:40 pm »
I've done some bash correction to correctly use XML calibration file.
Now the value displayed is correct and the result is very interresting.

I'm investigate to display digits with a little lower font size.

With the input shorted to the ground :
« Last Edit: August 12, 2019, 01:46:22 pm by alexvg »
 

Online alexvg

  • Regular Contributor
  • *
  • Posts: 78
  • Country: fr
Re: Hacking the Siglent SDM3055 Bench DMM
« Reply #14 on: August 13, 2019, 08:59:19 am »
Quote
How to test the sdm-mod ? (only with the latest 1.01.01.19 firmware)

Step 1
Plug a formatted FAT32 USB Key (I use 4GB) into the SDM3055

Step 2
Connect to telnet (username:root, password:ding123)

Step 3
Backup all Siglent data into the USB key :
"cp -R /usr/bin/siglent /usr/bin/siglent/usr/mass_storage/U-disk0/"
After copying, unplug the USB key

Step 4
Plug the USB key into your computer
Copy "sdm-mod.app" into the "/siglent" of the USB key
Unplug the USB key

Step 5
Plug the USB key into the SDM3055 and go to telnet
Stop the current sdm.app application : use "ps" to list all application PID and kill the "./sdm.app" PID.
Generally it's the PID 550, you could kill it with command "kill 550"

Step 6
Prepare and run the mod
"mkdir /usr/bin/siglent/usr/mod"
"cd /usr/bin/siglent/usr/mod"
"cp -R /usr/bin/siglent/usr/mass_storage/U-disk0/siglent/ /usr/bin/siglent/usr/mod/"
"cd siglent"
"./sdm-mod.app"

Step 7
To stop sdm-mod.app, just press "Control C".
Restart the device to return to normal operation.

Step 8
To remove the mod folder
"rm -r /usr/bin/siglent/usr/mod"


Code: [Select]
sdm-mod.app 20190812 v01
SHA1 : 85ceab5b27570de364ab127d0c67a7deb17903ab
SHA256 : d26b360d6db9a89b058b4d44a2116c546b492e402df37fa1d491276a415fd5d0

Features
- Add 2 digits (7 1/2 digits)

Drawback
- On some menu the sign and/or the last digit is not display correctly
« Last Edit: August 13, 2019, 09:11:53 am by alexvg »
 
The following users thanked this post: thm_w

Online alexvg

  • Regular Contributor
  • *
  • Posts: 78
  • Country: fr
Re: Hacking the Siglent SDM3055 Bench DMM
« Reply #15 on: August 13, 2019, 09:11:23 am »
I'll post later 2 other versions :
- sdm-mod.app with only one additionnal digit
- sdm-mod.app with two additionnal digits and some special text display (if it's work !!!)

I've not currently found the solution to change the font size.
It takes very long because my ARM debugger does not work...

If anyone know a solution to do a remote debugging of an ARMv7 GDBServer using Windows (or Debian)...

If you have a voltage reference, could you post your result ? (I use the BARmeter menu to display all digits)
« Last Edit: August 13, 2019, 09:14:13 am by alexvg »
 

Offline tv84

  • Frequent Contributor
  • **
  • Posts: 797
  • Country: pt
Re: Hacking the Siglent SDM3055 Bench DMM
« Reply #16 on: August 13, 2019, 09:54:58 am »
If anyone know a solution to do a remote debugging of an ARMv7 GDBServer using Windows (or Debian)...

IDA?
 

Offline Zorc

  • Contributor
  • Posts: 6
  • Country: nl
Re: Hacking the Siglent SDM3055 Bench DMM
« Reply #17 on: August 13, 2019, 01:35:42 pm »
 :-+ Very cool you've got this far!
Interesting to find out how usefull this actually is!
I don't have a benchtop DMM but maybe in the future this might be a model I would consider buying (whenever I decide I really 'need' (read: want to have) one to supplement my handheld multimeters)
 

Offline coromonadalix

  • Super Contributor
  • ***
  • Posts: 2016
  • Country: ca
Re: Hacking the Siglent SDM3055 Bench DMM
« Reply #18 on: August 13, 2019, 05:17:27 pm »
Has it been compared against a precision source  ??,  nice to have more digits,  are they worth displaying ??
 

Online alexvg

  • Regular Contributor
  • *
  • Posts: 78
  • Country: fr
Re: Hacking the Siglent SDM3055 Bench DMM
« Reply #19 on: August 13, 2019, 05:45:06 pm »
Has it been compared against a precision source  ??,  nice to have more digits,  are they worth displaying ??
I would like to know if additionnal digits are usefull or not.
The only thing I could say, there are an internal rounding error.

IDA?
I've tested IDA but it does not support this application and/or GDBServer integrated into the SDM3055.
 

Offline tv84

  • Frequent Contributor
  • **
  • Posts: 797
  • Country: pt
Re: Hacking the Siglent SDM3055 Bench DMM
« Reply #20 on: August 13, 2019, 05:46:35 pm »
I've tested IDA but it does not support this application and/or GDBServer integrated into the SDM3055.

What about via JTAG?
 

Online alexvg

  • Regular Contributor
  • *
  • Posts: 78
  • Country: fr
Re: Hacking the Siglent SDM3055 Bench DMM
« Reply #21 on: August 14, 2019, 06:31:30 am »
Here's the 6 1/2 digits version :

Code: [Select]
SDM 3055 m1-1908-01

Feature
- Add 1 digit (total of 6 1/2 digits or 2 400 000 points)

SHA1
cb89541b22959c8cdae8a7a917b29ca7042d4bcf

SHA256
73bef60988a4b4ec684132795c0f6b99bb4fcf4d4e1824f0acad414d9f9f64cb

Quote
How to test the sdm-mod ? (only with the latest 1.01.01.19 firmware)

Step 1
Plug a formatted FAT32 USB Key (I use 4GB) into the SDM3055

Step 2
Connect to telnet (username:root, password:ding123)

Step 3
Backup all Siglent data into the USB key :
"cp -R /usr/bin/siglent /usr/bin/siglent/usr/mass_storage/U-disk0/"
After copying, unplug the USB key

Step 4
Plug the USB key into your computer
Copy "sdm-mod.app" into the "/siglent" of the USB key
Unplug the USB key

Step 5
Plug the USB key into the SDM3055 and go to telnet
Stop the current sdm.app application : use "ps" to list all application PID and kill the "./sdm.app" PID.
Generally it's the PID 550, you could kill it with command "kill 550"

Step 6
Prepare and run the mod
"mkdir /usr/bin/siglent/usr/mod"
"cd /usr/bin/siglent/usr/mod"
"cp -R /usr/bin/siglent/usr/mass_storage/U-disk0/siglent/ /usr/bin/siglent/usr/mod/"
"cd siglent"
"./sdm.app"

Step 7
To stop sdm.app, just press "Control C".
Restart the device to return to normal operation.

Step 8
To remove the mod folder
"rm -r /usr/bin/siglent/usr/mod"
 

Online alexvg

  • Regular Contributor
  • *
  • Posts: 78
  • Country: fr
Re: Hacking the Siglent SDM3055 Bench DMM
« Reply #22 on: August 14, 2019, 10:13:37 am »
If anyone with a 3045X wants to test the 3055 in his DMM, I can easily prepare an .ADS.

BUT, no responsibility for my side.

Never try to use SDM3045X or SDM3065X into the SDM3055
- The SDM3065X app program have an error loop
- The SDM3045X app program seems to work, but there no value on the display.

I'm currently testing a modification : I've removed the 0.5uV add/sub.

Edit: If you want to use the initial mod version I've posted (7 1/2 digits), You need to use the stat menu to display all digits and sign without any artefact.
I've noticed after a measurement of a battery (around 8V), using 20V range, there's a +/-20uV variation. This corresponding to a +/-2uV at the input of the ADC (with its 2.5V reference).
This seems to be very good.
« Last Edit: August 14, 2019, 10:17:06 pm by alexvg »
 

Online alexvg

  • Regular Contributor
  • *
  • Posts: 78
  • Country: fr
Re: Hacking the Siglent SDM3055 Bench DMM
« Reply #23 on: August 16, 2019, 07:31:44 am »
I've add 2 little heat sink on voltage reference and ADC and I removed the fan.
The result is interresting (using 200mV range, short-circuit on the input and more than 4000 samples) :
- Previous noise result was 1.75uV
- Now the noise is reduced to 1.34uV (difference between min/max) and standard deviation is 0.207uV

I've mesured a -90dB noise into the 5V line... Why Siglent integrated the analog/logic power supply on the same board ? (except for lowering cost).
I'm thinking about adding a pre-rectifier/filter/regulator, changing the 5V regulator and probably changing the voltage reference to the LTC6655B-2.5 (if I could access to an excellent reference voltage).

I've received a AD584LH voltage reference, I've measured 20K samples at 2.5V with 20V range :
- 78uV span (+/-39uV)
- 11,1uV standard deviation

I think the SDM3055 seems to be more interresting than I though first (It only need some modifications to be more better).



« Last Edit: August 16, 2019, 05:15:41 pm by alexvg »
 

Online alexvg

  • Regular Contributor
  • *
  • Posts: 78
  • Country: fr
Re: Hacking the Siglent SDM3055 Bench DMM
« Reply #24 on: August 16, 2019, 11:23:49 pm »
I've tested IDA but it does not support this application and/or GDBServer integrated into the SDM3055.

What about via JTAG?
I've successfully running the remote debug using Texas Instrument Code Composer Studio...
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf