Measurements data logger for Rigol DM3058 multimeter

[kpt]

Hi there,

I would like to share information about data logger I have created over the years for DM3058 digital multimeter. My motivation for choosing this multimeter was that I needed measurements tool for creating battery charging and discharging IV curves and do some other readings with repeatable results. And it did not break the bank. As did my homework back then with datasheets, manuals and else I did know that it is not the best tool for logging measurements. Rigol data logging software was (or probably still is) paid option and having my PC on all the time while measuring was not something I was interested in. So I brewed up setup with micro controller that reads measurements using serial port to additional flash memory chip. Measurements can be retrieved sometime later to process data, create graphs and else. As I found it quite useful for my goals I guessed someone else might do so as well. Over the time I pushed design towards completed device – not just mesh of wires for my personal use. More details about the device can be checked here:

https://hackaday.io/project/166880-data-logger-device-for-dm3058-digital-multimeter

And here is video that shows how prototype is used:
https://youtu.be/Hhc5T10CXKM

It took some effort but device now is now somewhat ready for users. It got LCD screen, rubber boots and user manual as well. I have few items now listed on Tindie (USD) and eBay (EUR):
https://www.tindie.com/products/22342/
https://www.ebay.de/itm/303838972843/

I think this device extends significantly measurements logging possibilities with DM3058 multimeter. Even if more advanced DM3068 has more data memory, to log something exact and save it to USB flash is not very straightforward and easy thing to do. Data logger device I created would be most suitable for those who need to measure some process at known intervals and process those measurements.

[Helix70]

Looks very good. I didn't see the time interval stored in the CSV file anywhere. This is needed by anyone doing a data log. Is the firmware open source? Hardware?

[kpt]

Thanks for your input! Measurement interval is included at the beginning of csv file together with measurement mode used. This was not in prototype video, however, (but is described in manual). Knowing this value time column can be created with a few clicks and the use of Excel formulas. Now to think about it, it would also be possible to create timestamp entries in csv file while they are being prepared for USB storage mode.

Interval is not included with each measurement as this would use up storage and interval is expected to be mostly uniform. Interval value is stored with measurement file. It is in full seconds for long logging periods. For fast measurement rates actual interval between measurements is detected and value has more precision in seconds or milliseconds with decimal digits.

Neither firmware nor software is open source at the moment.