Recent posts

#21

PIC / Re: PIC-USB-4550 program does ...

Last post by LubOlimex - March 02, 2026, 04:48:39 PM

Umm wrong compiler for that code. You need PIC18 compiler in LITE mode:

https://www.microchip.com/en-us/development-tool/sw006011

It is free to download just requires registration.

#22

PIC / Re: PIC-USB-4550 program does ...

Last post by emil_bbb - March 01, 2026, 10:37:42 PM

I have also tried to compile the program in MPLAB X IDE v6.25 but I get error messages.
make -f nbproject/Makefile-default.mk SUBPROJECTS= .build-conf
make  -f nbproject/Makefile-default.mk dist/default/production/Bootloader.X.a
make[2]: Entering directory 'C:/Users/Emil.BC/MPLABXProjects/Bootloader.X'
"C:\Program Files\Microchip\xc8\v3.10\bin\xc8-cc.exe"  -mcpu=18F4550 -c   -mdfp="C:/Program Files/Microchip/MPLABX/v6.25/packs/Microchip/PIC18Fxxxx_DFP/1.7.171/xc8"  -memi=wordwrite -O0 -fasmfile -maddrqual=ignore -xassembler-with-cpp -mwarn=-3 -Wa,-a -DXPRJ_default=default  -msummary=-psect,-class,+mem,-hex,-file  -ginhx32 -Wl,--data-init -mno-keep-startup -mno-download -mno-default-config-bits   -std=c99 -gdwarf-3 -mstack=compiled:auto:auto:auto     -o build/default/production/bootloader.p1 bootloader.c
In file included from bootloader.c:6:
C:/Program Files/Microchip/MPLABX/v6.25/packs/Microchip/PIC18Fxxxx_DFP/1.7.171/xc8\pic\include\proc/pic18f4550.h:41:2: warning: Header file pic18f4550.h included directly. Use #include <xc.h> instead. [-W#warnings]
   41 | #warning Header file pic18f4550.h included directly. Use #include <xc.h> instead.
      |  ^
bootloader.c:22:5: error: use of undeclared identifier '_asm'
   22 |     _asm goto _startup _endasm
      |     ^
1 warning and 1 error generated.
make[2]: Leaving directory 'C:/Users/Emil.BC/MPLABXProjects/Bootloader.X'
make[2]: *** [nbproject/Makefile-default.mk:104: build/default/production/bootloader.p1] Error 1
make[1]: *** [nbproject/Makefile-default.mk:85: .build-conf] Error 2
make: *** [nbproject/Makefile-impl.mk:39: .build-impl] Error 2

BUILD FAILED (exit value 2, total time: 1s)

I find it impossible to load a working programm in the pic
Is there any other programm that works with the bootloader, other than the blinking led?

#23

ESP32 / Re: New ESP32-POE-ISO - was I ...

Last post by chrismacp - March 01, 2026, 12:29:42 AM

I'm wondering, before I start trying to solder anything. Are there any measurements I could take to confirm where the problem is. I'm most definitely an amateur at this stuff currently so trying to learn where I can.

I measured ~1.9v across pin 1 (GND) and pin 6 (Out according to datasheet although just 'x' in the Kicad file) of U7 when there is 5v applied to the 5v pin of the microcontroller board. It's ~1.4v when usb power is connected.

I'm not sure if that helps to figure out if the component is broken or not. 

#24

ST / Re: BB-STM32WL and Platformio/...

Last post by LubOlimex - February 27, 2026, 08:41:49 AM

I think you are correct. It seems the ESP-PROG design was made only for ESP boot sequence. I will add it as a note on the product page. Maybe jut use regular general-purpose USB-serial cable. Like:

https://www.olimex.com/Products/USB-Modules/Interfaces/USB-SERIAL-L/

USB-SERIAL-L does not internally couple RTS and CTS. But you must wire it properly and probably put like 1k resistor between RTS and boards RESET and between CTS and BOOT0.

#25

ESP32 / Re: What board should I use?

Last post by LubOlimex - February 27, 2026, 08:22:57 AM

Of course, PoE is optional. You can still power them from USB or external power supply and have a back-up Li-Po battery. The Ethernet is fully functional as long as the board is powered.

Notice that you can stack more than one MOD-IO board, just change the I2C address of the second, the third, and so on.

#26

ST / Re: BB-STM32WL and Platformio/...

Last post by winfried - February 26, 2026, 04:42:05 PM

Workin manual: the sequence is with buttons to GND:

BOOT0 -> low  (button closed)
RESET -> low  (button closed)
RESET -> high (button released)
BOOT0 -> high (button released)

--
To understand the Transistor Logic in ESP-PROG it did, thanks to KiCAD, a fast simulation on /RTS and /DTR to DCOM and EN see picture below:


It seems, there is no combination of both signals being low at the same time, so it does not work, or am I wrong ?

#27

ESP32 / Re: What board should I use?

Last post by fredy - February 26, 2026, 02:58:02 PM

Hi!!

Thanks for response and your advise!

Last question: could I use POE boards without use the power of POE and use the ethernet to send data?

Thanks in advance!

#28

ST / Re: BB-STM32WL and Platformio/...

Last post by LubOlimex - February 26, 2026, 08:31:29 AM

Hmmm, you might need oscilloscope for this one. I think the problem comes from ESP-PROG logic that is made for ESP auto-boot and STM32 boot logic is possibly different. Maybe try with

Code Select Expand

-i '-rts,,-dtr,100,dtr:,-rts'

Code Select Expand

upload_flags = -R -i '-rts,,-dtr,100,dtr:,-rts'
I think to enter STM32 system bootloader:

BOOT0 = HIGH
RESET = LOW
wait ~100 ms
RESET = HIGH
BOOT0 can stay HIGH (or go LOW after reset)

To exit bootloader:

BOOT0 = LOW
RESET pulse again

If it does not work, the signals may be inverted on your ESP-PROG. In that case, swap rts with -rts and dtr with -dtr. If possible, verify with a multimeter or oscilloscope that:

EN actually goes LOW during reset and BOOT0 actually goes HIGH during boot. That will show whether inversion is the issue.

#29

ST / Re: BB-STM32WL and Platformio/...

Last post by winfried - February 25, 2026, 09:24:01 PM

Trying to use the DCM and EN outputs from ESP-PROG for RESET and BOOT0 on BB-STM32WL board.

Also for "STM32flash" there are options to handle boot and reset, with "dtr" and "rts" pins with your ESP-PROG, (so I can make a dev connector on my board):

Code Select Expand

Code Select Expand

  ...
 -i GPIO_string  GPIO sequence to enter/exit bootloader mode
            GPIO_string=[entry_seq][:[exit_seq]]
            sequence=[-]n[,sequence]
 -R      Reset device at exit.
 ...

Code Select Expand

upload_flags = -R -i '-rts,,-dtr,,,dtr&rts:,-dtr,,,dtr'
        ; GPIO sequence adding delay after port opening:
        ; - entry sequence: rts=low,200ms,dtr=low, 300ms delay, dtr&rts=high
        ; - exit sequence:dtr=low, 300ms delay, dtr=high

Following questions:

Assume connect EN to RESET and DCM to BOOT0 I cannot find a working sequence.
Do not understand what is the logic of DTR with RTS  to EN and DCOM signals on ESP-PROG.

What could be a sequence of DTR and RTS to: "DCM low" and "EN low, 100ms, high" for reset and make DCM high again ?

#30

New Product Ideas / Re: Which board might fit for ...

Last post by LubOlimex - February 25, 2026, 08:20:57 AM

I think the only board that fits the open-hardware criteria, 2GB of RAM and being slim is iMX8MP-SOM-4GB-IND. The rest of the SOM designs we have are not open-source hardware The idea of the SOM is to design own bottom board that exposes only the interfaces you need, while the EVB board features most of the peripherals to serve as evaluation basis for the chip, the peripherals and the Linux.

The web-page is here:

https://www.olimex.com/Products/SOM/NXP-iMX8/iMX8MP-SOM-4GB-IND/open-source-hardware