writeup

Roland SR-JV80 Re-writable ROM Card with ESP32

by ddzheng
For user manual and purchasing please visit: https://www.ddzheng.cc/?page_id=666 Update 13 Feb. 2025: The first batch run has finished. This will be also PVT. change to reverse mounted 1206 led on bottom side. Update 29 Jan 2025: Out of advice from Gearspace user I will add a header footprint for remote mounted button. I added ability ... Read More

Tektronix DPO71254B Repair

by ddzheng
There is a DPO71254B at my workplace that has been abandoned for quite a while. I repaired it so that we can use it to debug (no cal though)

Oscilloscope Measurement Artifacts 1

by ddzheng
In this article I present some aspects that distort electrical signal measurement result, with focus on what happens in the scope itself after the signal has entered an oscilloscope.