| Electronics > Projects, Designs, and Technical Stuff |
| Hacking a surprisingly good Uni-T multimeter. Teardown and serial com upgrade |
| (1/1) |
| paulossant:
After seeing some multimeter teardown videos from Dave Jones, I was worried about what he shown from the cheap Uni-T multimeters, especially about thei input protection. So... since I use one (Uni-t UT133A), I opened mine to see whats inside, and must confess I was happy to see what I've saw. check the pictures! Ceramic fuses, PTC and varistors... Very nice layout.. UL certified! So.. all was good! :-+ Next, I decided to see if the blob controller was outputting anything on the Tx Rx pads... and connected the oscilloscope to it and.. it was output something! Nice! :-+ Finally connected connected Tx to my logic analyzer and started to try figure it out. After a few minutes, and google search to see any uni-t multimeter serial protocols, figured it was rs232, LSB first 8N1, 2400 Baud.. Then created a .ods file in libreoffice calc and wrote some of the outputs.. So all it is needed to use the multimeter as a datalogger is to test the Tx line, plug it into a micro and create a GUI. Which could be easily done with a stm32f103, and create a GUI with QtPy... Will it be worth it? :-// Tell me what you think! I leave attached the .ods file with what i've done so far. |
| uer166:
It is not UL certified, it "conforms to a UL standard", but UL have never seen this meter. |
| 2N3055:
--- Quote from: uer166 on June 07, 2020, 02:12:06 am ---It is not UL certified, it "conforms to a UL standard", but UL have never seen this meter. --- End quote --- ETL listing is equivalent to UL listing, and Intertek is reputable company. |
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