UT61E SD BLE logger

Recently (few days ago) I have bought UT61E for current logging.
While in mA selection it can measure 1uA so it is good for my lora experiments.
Now I log current over RS232, but my plan is to make nrf52 logger.
I did try to measure voltage directly on diode, but it is only 1.2V so I will need to make small board with opto transistor so I do not mess much with multi meter board…

You might find this useful. -> http://stm32duino.com/viewtopic.php?f=4 … 704#p16704

tnx I did it already with 74HC04 but I have problem with serial

https://2.bp.blogspot.com/-D8PK8wDGYUs/ … ematic.JPG

and I can read data with just USB-SERIAL

Just try to use cubeMX to setup serial
But i do not get serial interrupt

I need 19200, bits 7, stop 1, parity odd.
and did set (8 bits include parity ) 7 is not available

Ok, got data now I need to parse …
https://github.com/goran-mahovlic/dmm_ut61e

If you are using Linux, you might find these useful.

http://www.mtoussaint.de/qtdmm.html#description

https://github.com/pingumacpenguin/QtDM … /README.md

https://sigrok.org/wiki/Multimeter_ICs

.. actually they are also useful even if you use Windows, since you can use the code and the code changes I made to see how your protocol is implemented (assuming it is supported), or implement it based on how other similar protocols work if it is not already supported.

That is quite nice.
So I can just log RAW data on SD, and on button press I can just send to USB complete log.

Next step is to save RAW data to SD…

UT61E protocol is not supported in QtDMM

So I did not have time to implement SD logger.
But did add initial protocol support to QtDMM

Now I have some values on screen (this is data from bluepill at 115200) and I needed to change last two bytes to be recognized by QtDMM

gotLog.png (71.2 KiB) Viewed 447 times

Good progress.

keeping an eye on this, also bought a UT61E for its logging capabilities
Maybe also worth mentioning here: when mine arrived a few segments on its display were hardly visible (luckily this meant there was a signal & they weren’t broken). A bit of googling showed me some videos on how to clean the contacts going to the lcd’s of fluke meters. The UT61E has the same kind of contacts, so after opening it up, i clearly saw some oxidized contacts, cleaned them with a qtip & some acetone, and now it’s working like new .

Oxidation on the contacts of “zebra strip” LCDs has caused many a consumer device to head for landfill. I recently threw out (well threw back in the scrap box), an LCD alarm clock with an NPL (MSF) receiver that someone had donated to me a few years back.

The corrosion on the LCD contacts caused by leaking batteries was so bad that it was impractical to attempt a repair.

I did salvage the ferrite coil/cap, so I may take a stab at building a receiver out of that, but given the price of GPS modules these days, which are more accurate, (but probably use more power) it may never happen.

EDIT: “The signal’s carrier frequency is maintained at 60 kHz to within 2 parts in 1012, controlled by caesium atomic clocks at the radio station.” … actually the MSF signal is probably just as accurate as GPS

Got some progress but something is still wrong

circular buffer is working (well led blinks and usb serial prints my message)

dataSaved.png (42.04 KiB) Viewed 278 times

Now I removed DMA it is really not needed for this speed

But still file is created only some time.
Rest of the time
FR_OK is not OK

But now without DMA I get real data on SD card…

Here is some log that is created sometime

LOG0002.TXT

(84 Bytes) Downloaded 123 times

My setup …

UNI-T61E.JPG (109.07 KiB) Viewed 262 times

Adding small delay fixed writing to SD, and creating new file.

Now I just need to read and write to USB on press of a button …

Ok, manage to get log from SD on press of a button

GotLoGFromSD.png (46.95 KiB) Viewed 221 times

Ok got graph

GotFirstGraph.png (21.34 KiB) Viewed 193 times