sam. 09 octobre 2021

HP 34970A Data Acquisition Unit - part 6

Quick follow up; I recently got back on this project to try to complete it and fix remaining problems.

The source code for the firmware is available here:

https://hg.sr.ht/~douardda/hp34970-firmware

The Kicad project is available here:

https://git.sr.ht/~douardda/hp34970-pcb

Making the USBDevice work …

sam. 07 novembre 2020

HP 34970A Data Acquisition Unit - part 5

After a loooong pause on this project, I have recently been able to work on it again. In the previous post in this series, I've started to implement a replacement board prototype based on a an NUCLEO board and an SSD1322-based OLED display.

Meanwhile, I have also almost completely described …

dim. 18 septembre 2016

HP 34970A Data Acquisition Unit - communication protocol

In order to build a replacement display for the HP34970A data acquisition unit, I needed to understand the communication protocol between the CPU board and the front panel assembly.

General description

The unit is built with four boards:

  • A1 is the main bard, with the PSU, the main controller and …

sam. 17 septembre 2016

HP 34970A Data Acquisition Unit - part 4

After a summer pause, I'm back on my HP34970A repair project. In the previous post in this series, I've started to reverse engineer the serial protocol between the CPU board and the front panel, and implement a prototype of replacement display.

OLED display

I bought the bigest OLED display I …

dim. 26 juin 2016

HP 34970A Data Acquisition Unit - part 3

As explained in the previous post in this series, I've started to sniff the serial protocol between the main board and the display panel so I can replace the failed VFD by an OLED or TFT display managed by an arduino or similar.

Protocol

The serial communication takes place at …

mer. 22 juin 2016

HP 34970A Data Acquisition Unit - part 2

This is quick follow up of my previous blog post on my attempt to fix my recently acquired HP 34970A.

In my hurry to replace the failing FRAM (FM24C04) chips, I also replaced the FRAM chip on one of my 2 plugin modules.

Bad idea: the module then provoques an …

lun. 13 juin 2016

HP 34970A Data Acquisition Unit

I recently "scored" a HP 34970A with the DMM included and 2 plugin cards (HP 34901A and HP 34907A) for less than 200€. The plugins should be in working condition, but the main switch unit was almost "given" with the plugin modules since it is non functional.

front view of the HP 34970A data acquisition unit

It's in very …