Support for HW version v3?

herm / ZPB30A1_Firmware

Open-Source firmware for chinese electronic load 60W/110W ZPB30A1

GNU General Public License v3.0

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Support for HW version v3? #7

Open lsr1 opened 1 month ago

lsr1 commented 1 month ago

Hi,

I have HW version 3 of the ZPB30A1P. To be more exact: v3.1 of the board with the load, and v3.0 of the small daughter board with the displays and the controls.

Is there any way (or interest) to collaborate to get this working on the new HW? I tried soldering on a new chip, and flashed the sw version for 2.9, but to (as expected) no avail.

What I could offer: a) detailed pics of the HW b) various measurements c) order a v3 to your/an address (depends on details)

Don't feel obliged!

lsr1

herm commented 3 weeks ago

Currently I don't have enough spare time to work on a major revision of this project. You can upload some photos of the boards here and I will compare them to my revision and estimate if adding support is something that can be done in reasonable time. But I won't promise anything.

lsr1 commented 1 week ago

Totally understood - please don't feel obliged at all. I have added some pictures (apologies for the potato cam - I only have a rather old cellphone. If you need other angles, other areas accentuated, plz don't hesitate to let me know.

lsr1 commented 1 week ago

load.zip

herm commented 1 week ago

It doesn't look very different from my version. However I noticed to bad things:

The debug connector is gone. You either have to check if the required pins are available on some pads or solder wires directly to MCU pins.
The MCU seems to have no marking at all. I'm not sure if it is just some artifact of the camera. If there is no marking that probably means it is some ultra-cheap Chinese IC for which you usually can't get any documentation at all. In this case there is nothing I can do to support this revision.

I also noticed that there are no 7-segment drivers on the display board. Are the below the displays? It is also possible that the LEDs are now driven directly from the MCU. This would mean that we have to change the software to support it.

zerog2k commented 1 week ago

The LED drivers are surface mount, under the segmented LEDs. Even the best "value engineering" can't get that many independent LEDs out of that many pins without some kind of help ;)

But I agree, no marking MCU is a bad sign. Maybe even OTP :(

@lsr1 Your first step would be to identify that MCU.

lsr1 commented 1 week ago

Hi - thanks for all your pointers!

There are chips under the LED 7segment displays (it's possible to see them from the side, but impossible to take a pic), but I would really like to not unsolder those if it can be avoided (I'll do that if required).

@zerog2k

I attached a picture of the original MCU. AFAICT, it reads: STM8S00 SK6T6C 9908Y VG MYS 044

STM

@herm I would argue the debug connector is still there - there are 4 solderpads (instead of the THT holes in earlier board verions) to the right side of the buzzer. I did use them (had dupont pigtails soldered on to them) to flash the "wrong" firmware version, after I had resolderd a virgin replacement chip (bought this one: https://www.aliexpress.com/item/1005006979827996.html ).