TH2830 vs TH2832

[mawyatt]

Probably the usual Cal Labs here in US. Expect a hefty bill tho

I've never sent anything for cal before, so I have no idea who is trustworthy. What is hefty? Over $200? More?

A good Cal lab likely charges well over $200/hr, so would expect well over $200 charge.

Best,

[KungFuJosh]

The patch doesn't go there near. Maybe the info is stored as ST2830 (Ax) and when the software tries to retrieve it as ST2832, it fails.

That's why I say that a direct change in the FRAM/whatever from Ax to Cx would make all good without FW patchings.

Did you swap any calls between Ax and Cx? If so, what about modding the fw so that Cx works on Ax and the other references to Ax are left alone? In other words, only change references to Cx, and leave the Ax stuff unchanged?

I think Rudi can get a memory dump of his 2832.

What about my theory about setting the ID over SCPI or USB or RS-232C? Unfortunately, I don't know jack about SCPI stuff.

Thanks,
Josh

[KungFuJosh]

A good Cal lab likely charges well over $200/hr, so would expect well over $200 charge.

Hmmm. No thanks! 🤣🤣🤣

Looks like I'll calibrate it myself and call that good enough. I don't need certification, I just need it to be at least as accurate as my other meters.

[tv84]

Did you swap any calls between Ax and Cx? If so, what about modding the fw so that Cx works on Ax and the other references to Ax are left alone? In other words, only change references to Cx, and leave the Ax stuff unchanged?

No change. That is Hollywood stuff...

[KungFuJosh]

Did you swap any calls between Ax and Cx? If so, what about modding the fw so that Cx works on Ax and the other references to Ax are left alone? In other words, only change references to Cx, and leave the Ax stuff unchanged?

No change. That is Hollywood stuff...

Crap, Hollywood's still on strike too, so they're not going to help. 😉

[KungFuJosh]

The patch doesn't go there near. Maybe the info is stored as ST2830 (Ax) and when the software tries to retrieve it as ST2832, it fails.

Did the patch only modify the header, or were there multiple instances that you needed to change? I can't think of a reason why the version number would need to be referenced for stored data.

[KungFuJosh]

This is an older thread, but it has an eeprom dump (reply 12) from one of tonghui's handheld meters: https://www.eevblog.com/forum/testgear/tonghui-th2822-lcr-meter-review-teardown-and-possible-hacking/

I don't know if that helps us or not, maybe it will show something useful.

[Martin72]

Depending on the size you won´t have to desolder the eeprom, with luck.
I used a SOIC-8 clip for reading out/programming the eeprom of my uni-t current clamp.

https://www.adafruit.com/product/5315

[KungFuJosh]

Depending on the size you won´t have to desolder the eeprom, with luck.
I used a SOIC-8 clip for reading out/programming the eeprom of my uni-t current clamp.

https://www.adafruit.com/product/5315

I don't have any intent to desolder anything on this. I have a sneaking suspicion it will wind up being easier than expected. We'll see though. Hopefully Rudi is able to dump enough data.

[luudee]

I don't have any intent to desolder anything on this. I have a sneaking suspicion it will wind up being easier than expected. We'll see though. Hopefully Rudi is able to dump enough data.

I have dumps of the I2C EEPROMS (the B85RC64TA, and the AT24C512)

I did not dump the two Adesto 45DB321E SPI Flashes because TV84 told me he did not need those anymore ...

Now my unit is back in my rack, which is a huge pia to pull out ... it's not trivial ....

I will dump the Adesto FLASH's if that is absolutely necessary.

The question really is: Who will decode the Adesto dumps ?

BTW: There is no need to de-solder the FLASH chips if you know what you are doing ;-)


Cheers,
luudee

[KungFuJosh]

I have dumps of the I2C EEPROMS (the B85RC64TA, and the AT24C512)

Awesome, thank you! Can you post them here, or are they too big?

Now my unit is back in my rack, which is a huge pia to pull out ... it's not trivial ....

What kind of rack? Standard 19" or something smaller? I want to make a narrow rack for my bench gear.

[Martin72]

I'll check tomorrow how many protocols are stored in our database.

Found two, the last from May2023.
After removing names and other sensitive data I´ll upload it here.
A little disappointment is that they´re using testfrequencies up to 10khz max.
But they will have their reasons to do so I guess.

[luudee]

Here are the dumps of the I2C EEPROMS (the B85RC64TA, and the AT24C512)
They should be exactly 8K and 64K bytes.

luudee

[KungFuJosh]

some good 0.1% low TC chip resistors

What do you consider low TC? There's a pretty huge range available. I'd like to get the best option without paying too much per resistor.

Is 25ppm/C good enough? I have some in my cart that range from 5ppm to 25ppm/C.

[nctnico]

What is the spec of the LCR meter? If you want some calibration worthy standards then get parts that are 10 times better. In some designs I use 0.01% 2ppm SMT resistors as references (which are calibrated using a 6.5 digit DMM later on). These resistors are like 15 euro each from Mouser IIRC.

[KungFuJosh]

What is the spec of the LCR meter? If you want some calibration worthy standards then get parts that are 10 times better. In some designs I use 0.01% 2ppm SMT resistors as references (which are calibrated using a 6.5 digit DMM later on). These resistors are like 15 euro each from Mouser IIRC.

It claims 6 digits, .05% accuracy. Spec sheet attached. I want to get multiple test points, and extras, so I'd rather not pay $10+ per resistor (if possible). 😉

[Martin72]

I have the calibration protocol from our ST2830, in the protocol the references are listed they used for it.
For Capacitance:

https://www.ietlabs.com/pdf/Datasheets/1404.pdf

https://www.ietlabs.com/pdf/Datasheets/1409.pdf

For Inductance:

https://www.ietlabs.com/pdf/Datasheets/1482.pdf

[KungFuJosh]

For a 1Ω 0.1% SMD resistor my choices are 25ppm/C for $0.48, or 2ppm/C for $52.47.

I think I'm going to say 25ppm/C is good enough for me. 🤣🤣🤣

[tv84]

If I were to bet, I would say luudee's files are AT - calibration and MB - settings.

The curious fact is that the mb85rc64t dump contains explicitly the "2830" reference, and he has a 2832 if I'm not mistaken.

[Martin72]

calibration

Hmm..
Let´s hope this is the place were the open/short-calibrations are stored and nothing else.

[KungFuJosh]

The curious fact is that the mb85rc64t dump contains explicitly the "2830" reference, and he has a 2832 if I'm not mistaken.

You're correct. All the hardware says 2830 also. The only piece physically that's different is the sticker on the front.

It seems the hardware ID we're actually looking for isn't stored on either of those 2 chips?

BTW- I saw this video:

He's able to call the version numbers up in his terminal window. Is this a route we should consider also to try and modify that?

[nctnico]

The AT24C512 is nearly empty. There are 64 bytes of data at 0xc000 and 0xe000 and that's it. Maybe this flash is where the user defined system settings are getting stored in.

[KungFuJosh]

The AT24C512 is nearly empty. There are 64 bytes of data at 0xc000 and 0xe000 and that's it. Maybe this flash is where the user defined system settings are getting stored in.

The spec sheet says "Built-in Storage Internal 100 LCRZ instrument setting files, 201 times test results" - maybe that's what those 2 chips are.

[nctnico]

That is possible. There is also an internal EEPROM inside the LPC1788 which could have the model ID inside. Only way to find out is to write software into the chip that can dump the internal EEPROM.

[KungFuJosh]

That is possible. There is also an internal EEPROM inside the LPC1788 which could have the model ID inside. Only way to find out is to write software into the chip that can dump the internal EEPROM.

That's beyond my skills. Anybody else? lol