Two stm32f103 boards Firmware MOD-UPGRADE for laser etcher-cutter CNC 3D printer HELP

Hello everyone I am working on a new set of controller cards to hack and would love all the help I can get.
So I have two boards I'm working on. ONE is just becuase its 90% the same and i'll be talking the most about in this post, the other card is because I need/want it for my laser etcher MCU upgrade. First off the board I'm hoping to upgrade my laser etcher with is an OLIMEXINO-STM32 . This board has an ARDUINO UNO footprint and is directly compatible with Arduino Uno hats sporting the STM32F103RBT6 with a 128kb flash. Much of this post currently is about the MACH3 USB CNC CARD BSMCE04U. It has more or less the same MCU the stm32f103rct6. The RCT6 has 256k flash. Everything below is covering the mach3 usb cnc card as of this posts date I have not yet received the OLIMEXINO in the mail yet.

These cards are plentiful and dirt cheap... So what I'm looking at is what is the best way to upgrade this card? I believe this card is a great candidate to be firmware upgraded with GRBL, MARLIN, Machinekit or maybe even SMOOTHIE, what do all of you think would be the best candidate for this card with the stock STM32 MCU? The controller chip the STM32F103RCT6 is pin compatible with a few different other chips. It could be swapped to an STM32F103RET6 which sports 512k flash and more ram. The current controller card has 256k flash. Now there are other chips like the GD32F103 which run at 108mhz over the 72mhz the STM run at. That could maybe be a nice upgrade as well? So I'm looking for guidance and advice on how to go about getting this card upgraded with better firmware. So far I have done some pin tracing, and found that the serial pins for upgrading the firmware are available.

If anyone is able to help I'd love to get GRBL? SUPERGRBL compiled for the STM32F103RCT6 and STM32F103RBT6 which are on the boards as is, and an Arduino bootloader as well so the card could be upgraded at any time further with out needing the serial setup. I know compiling grbl for this board will require some adjustments to I/O assignments to begin with. Now because of personal life issues I have at the moment, I have not had much time to dive into this project yet and give a full pinout post. I am also assuming that there are going to require some minor SMD mods with resistor(s) to deal with bootloader(s).

I may have made some errors but I dont believe so. The pins on the chip are very small, though I used a USB microscope when testing the pins. So far as I can tell the board construction is only a 2 layer top/bottom and the only bottom traces going from the stm32 chip to anything are to the idc header. All other traces are top side mounted. PIN 46 PA13 SWDIO, PIN 49 PA14 SWCLK. ON the chip its self the little circle is the pin 1 VDD/pin 64 VBATT location both are connected to the 3.3v regulator. THE BIG tab and the center small tab are both output from the ams1117 linear regulator. With this info that should be enough for anyone to start digging into this controller.


PLEASE SPARE ME THE HATE.... I built an input adapter for the 2x5 header when I tested the board with mach3 <-- SUCKED BTW but the input is very signal sensitive I had to build one of these adapters https://www.cnczone.com/forums/contr...13028-cnc.html an other one of my posts. It cleaned up the signal wonderfully. I'll post a photo of my PERF board when I get around to it.
There are 4 12/24v outputs, 4 12/24v inputs, PWM output and 4 motor step/dir signals built into the board. The IDC 2x5 header has +5v, grd, 6 GPIO's, I have not DMM'ed the board to identify how the resistors are arranged yet? pull up/down-inline?? not sure.

The overall goal is to upgrade to the OLIMEXINO-STM32 "ARDUINO UNO footprint board" that I plan to put into this laser etcher that I'm building, LASER ETCHER . The uno works but its not great for high speed or raster images which is mainly what I'm going to be dealing with. Also the step rate suffers a shudder issue if the Arduino is overwhelmed.

If anyone is interested in my GRBL control panel I designed that is in my LASER ETCHER link of progress photos. post about it and I'll see if I can find my source files and GCODE files etc...... and publish them. That would include the main visible board, the PCB board mounted to and under the main visible board. And the break out pcb board inside the white controller shell that is part of my laser etcher. The breakout board has the main lock out relays for mains power and laser power for safety.

If anyone can help post a schematic/PINOUT before I get to it for the BSMCE04U mach3 controller Please by all means. The OLIMEXINO-STM32 has full documentation being that its "DESIGNED " for customizing. There are 9 opto isolators "el357n" 4 on the high power input, 4 on the high power output, one on the PWM laser/spindle ctrl "avi" header. The outputs for driving relays etc... are controlled by a ULN2003 and opto isolation stm32 MCU side. The STEP/DIR for X,Y,Z,A step motion generation are driven by at HC541 Octal Buffer. Everything else on the board is made up of resistors, caps, diodes, one transistor, one linear regulator, a crystal and an LED. That about sums it up other then header header connections.

I'm taking a little bit of time tonight that I have a moment to build the ST-link header. I'll post a high detail photo later on when it is complete to show how to build the interface. to sum it up. the pin spacing of the round pads is for standard JST headers. So I'm using a horizonal 2x2 header. I'm laying it on its back tacking the longest two legs to the pads, and the shorter legs will have wire jumps to 3.3v and grd. That will provide everything needed to access the chip on a direct programming level. lets see if I'm right!

I have accessed the chip with my ST-link setup photos to follow, something I have just learned by default you can read the stm32 after clearing the write/read code protection (CLEARING THE CHIP) just remember if you build my adapter setup you will brick the original code on the mach3 usb cnc adapter. and it will no longer be usable by mach3. BOOT0 stm32f103 pin 60 is tied to ground. we will need to cut the trace and run wires to a jumper to be able to select between 3.3v/grd for programming reasons.

Attachment 462206 2x2 header 2 to the round headers, two wire jumped to 3.3v/ground bottom left 3.3v, bottom right grd, back right pa13, back left pa14

BOOT0 selection pin60. you must cut the trace which is tied to ground. setup a jumper and hot glue it down. If you load firmware that changes the boot method. You will need to change the jumper to be able to re-program the chip. BOOT0 to +v 3.3v to program, BOOT0 to ground to run program. I'll post a photo when I get a chance.

Board LED tied to pin 9 PC1 active high. pin 52 PC11 is connected to the base of a 2A PNP SMD transistor which is connected to D+ of the USB port for soft reset and active low I believe, the other side of the transistor is tied to +3.3v.

The BOOT0 mod complete and tested works wonderful.

Now that the HARDWARE mod has been finished. I'm looking for help from anyone that does STM32 coding. My over all goal for now is to get GRBL onto the stm32. I know there is stm32duino and I dont know anything about it, and I have never coded for stm32 only arduino. I'd like to get the arduino bootloader onto this card. then hacking will be easy from there I hope.

I looked into this a few months ago. One major problems is the stm32 grbl code as written requires the step and direction I/O to be on the same port. The Bitsensor board has the step and direction I/O on two different ports. The grbl code needs to be changed to make happen. I’m not sure how difficult it is to change that.

swapping pins would be very easy. I have not had a lot of time as of late but finding a good location to do a simple trace cut and trace jump would be no problem. Though code adjustment would be the smarter way to approach this. I my self is NOT a coder, I can edit code but code on the GRBL source level is a little over my head.

Attachment 462674
here is the bitsensor stm pinout and the corresponding grbl assignment

nice work

This weekend I will upload the pcb drawing and gcode files for the ST-link adapter board I built. And the GCODE files for anyone who is interested in building the board and has a cnc machine.

I'll post photos and details soon as I get a chance on the olimexino-stm32 ST-LINK header. thought the details are available as far as pinout etc.... in the form of a PDF manual.... My adapter works just fine and I am able to read the chip just fine. A friend of mine is working on re-coding and compiling GRBL for the stm32 OLIMEXINO board..... when he's finished I'll post the code.

New photos of the laser etcher and finished 3d prints. https://photos.app.goo.gl/1ejmwQjHGskbBvob9 . everything is working at its current design and minimum state of need. I'll be switching focus back to the stm32 soon. If there is interest I can publish my 3d prints.

found some wiring issues for the OLIMEXINO and grbl

we are working on it. but it looks like we can just generate a two sided PCB and correct the wires. sucks to have a DBL hat setup but at least it will make the olimexino usable as a grbl controller

we are working on it. but it looks like we can just generate a two sided PCB and correct the wires. sucks to have a DBL hat setup but at least it will make the olimexino usable as a grbl controller. so more or less there are some issues where the stm32 passes port b or port a pins in an area that the arduino has all port A or all port B pins. do to this it breaks GRBL. so the correction is to simply re-direct the stm32/arduino foot print. to the standard arduino ports pinout foot print. and grbl is no longer broken. The alternative would be to have the motor shield remote and wires jumping to the correct locations. no so desirable.