exxos's Atari, Amiga & retro forum

olivier.jan wrote: 11 Jul 2023 18:05 Yes, you should test your Bluepill. While testing my internal ACSI2STM for MegaSTE board I ran into various issues with a fake bluepill. After testing with https://mecrisp-stellaris-folkdoc.sour ... -v1.6.html I finally found some good ones and all the issues where gone

@olivier.jan I just tried this diagnostic tool and whilst I can flash it to my BluePILLs just fine, my PC doesn't pick up any serial device at all.

Did you need to set the jumpers for it specifically to work?

I remember running into some issues with the serial connection, but I need to test again. I will try tomorrow during lunch break, I have a few fakes and real STM32. Btw, I finally built my internal BlueSCSI last weekend but didn’t have the time to test it inside the Classic yet. Wasted too much time on a “10 minutes fix” for a mega ST motherboard which ended up not booting at all after the fix 😭. Hopefully I’ll be able to test the BlueSCSI this weekend: in order to reproduce your issue, you boot from ROM with only one volume on the BlueSCSI SD card and you try to initialize the volume, do you ?

olivier.jan wrote: 20 Jul 2023 19:04 I remember running into some issues with the serial connection, but I need to test again. I will try tomorrow during lunch break, I have a few fakes and real STM32. Btw, I finally built my internal BlueSCSI last weekend but didn’t have the time to test it inside the Classic yet. Wasted too much time on a “10 minutes fix” for a mega ST motherboard which ended up not booting at all after the fix 😭. Hopefully I’ll be able to test the BlueSCSI this weekend: in order to reproduce your issue, you boot from ROM with only one volume on the BlueSCSI SD card and you try to initialize the volume, do you ?

I think we've probably all been there with the '10 minute fix' :)

I'd be grateful if you could try when you have a spare moment, the symptom I get is that after flashing the diagnostics Windows detects it as a USB device, but can't detect what sort of device it is, so there is no serial connection to work with.

In terms of using it a s BlueSCSI, I flashed it with an STM Link and STM Cube software. I 'suspect' one Blue Pill is bad as I can't directly erase it, though I can still flash it (It erases during flashing OK though)

It sees the SD card and any drive images and writes correctly to the log file on the SD card.

And yes, I am using a single 80MB HD image created with DD on my Mac with a 512KB block size. If I partition with the patched HD Tool, it sees the disk just fine and allows me to partition and install an OS, but it won't subsequently boot from that OS, it crashes, usually just before it's completed booting.

@olivier.jan

Firstly I have now managed to erase both devices fully before flashing the test firmware. That's a tick in the box

However, the BluePills I have are not recognised by the PC, but looking around I found this: Blue Pill - Incorrect pull up resistor

This seemingly means USB doesn't work, so I'm going to look into that next and hopefully it'll help me move forward.

Hi,
So I finally tried the test software on three different Bluepills this morning. After spending 20 minutes looking for my ST Link, I finally ended up flashing using a serial adapter connected to A9 and A10. After flashing, a new USB Serial port appears and connecting to it gives a blank screen (I tried 230400 bauds and 9600 bauds, both successfully).
Once connected, I just pressed 'm' to get to the menu.
All this was done on macOS (I don't have a PC) but I tried connecting with Tera Term from a Windows VM and it worked too.
Last but not least, it worked fine for 2 out of the 3 Bluepills, the third one can be flashed but the new USB Serial port never shows up.
Checking the resistor values based on your article shows all three boards have a correct value. The only hint is that the non working one has a very suspicious look compared to the others, Jumper colour is different and silkscreen markings is very blurry.

olivier.jan wrote: 21 Jul 2023 11:09 Hi,
So I finally tried the test software on three different Bluepills this morning. After spending 20 minutes looking for my ST Link, I finally ended up flashing using a serial adapter connected to A9 and A10. After flashing, a new USB Serial port appears and connecting to it gives a blank screen (I tried 230400 bauds and 9600 bauds, both successfully).
Once connected, I just pressed 'm' to get to the menu.
All this was done on macOS (I don't have a PC) but I tried connecting with Tera Term from a Windows VM and it worked too.
Last but not least, it worked fine for 2 out of the 3 Bluepills, the third one can be flashed but the new USB Serial port never shows up.

Cool, thanks. I will check the pull ups and report back, it may just be that, we'll see.

I checked one of the BluePills and the pullup is correct, so given they came from the same source, I'm assuming the other is good.

In addition, I erased again and was able to flash an STM bootloader, and that does work when connected to a terminal.

So it seems that the current diagnostics don't work with my BluePills, so I'll try an older version.

The problem is that very few "BluePills" are actually the same as the original. They're all approximations and often don't even have an STM chip.

stephen_usher wrote: 21 Jul 2023 14:19 The problem is that very few "BluePills" are actually the same as the original. They're all approximations and often don't even have an STM chip.

Visually mine pass the tests, but I'm beginning to think they are fakes.

Given that the original BluePill was a cheap no-name Chinese board they're all "fakes".