Author Topic: LED display for HP 3457A multimeter - I did it :-) (Read 80349 times)

fenugrec · « **Reply #150 on:** April 03, 2026, 12:50:11 pm »

re '5' and 'O' character swaps : for the 3478 at least, that would also be fixable at the original firmware level : https://www.eevblog.com/forum/projects/led-display-for-hp-3457a-multimeter-i-did-it-)/msg2893910/#msg2893910

probably two NOPs, fix checksum, and done.

nearly identical fix on the 3468, somewhere around 0x0A2A

bungle · « **Reply #151 on:** May 23, 2026, 11:14:06 pm »

I just did Ian's conversion to my 3478a, works great.

I had to order a minimum of 5 pcbs so I have 4 left over. If anyone in the US wants one, let me know and i'll throw one (and the 3d printed TFT mount if you don't have a printer) in USPS to you.

Matt

sleibson · « **Reply #152 on:** July 16, 2026, 05:48:11 pm »

Hi Matt, if you still have a pcb for the mod, I'd appreciate one, and would take you up on the 3D printed version. I just got the OLED and plan to order the micro. Please write to me at [email protected] and I'll send you an address. Thanks!

bungle · « **Reply #153 on:** July 16, 2026, 06:34:40 pm »

Update - two people have taken me up on this offer so far, I have two more remaining


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Author Topic: LED display for HP 3457A multimeter - I did it :-) (Read 80349 times)

fenugrec

Re: LED display for HP 3457A multimeter - I did it :-)

bungle

Re: LED display for HP 3457A multimeter - I did it :-)

sleibson

Re: LED display for HP 3457A multimeter - I did it :-)

bungle

Re: LED display for HP 3457A multimeter - I did it :-)

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