Unfortunately the STM32WB Feather Development Board is no longer available. But there is a very good substitute the Firefly designed by Tlera Corp. The pinout is very similar to Arduino UNO but with the size of an Arduino Nano (or a Teensy). The GPIOs are very carefully selected. JTAG SWD is on the pin header too!

Instant real-time programming with Forth.

Sources on GitHub (Firefly branch on Mecrisp-Cube)

Features

The standard Mecrisp-Cube features like RTOS, Filesystem, USB, etc.

• 63 KiB RAM Forth dictionary
• 128 KiB Flash Forth dictionary
• 50 KiB for C code
• Internal Flash drive 0:, 384 KiB (for details see Nucleo)
• microSD drive 1: (needs external adapter)
• Digital and analog pins
  • LED1 (blue), PE4
  • Button, PH3
  • Digital port pins: D0 to D15
  • Analog port pins: A0 to A4
  • PWM: TIM1CH3 D0, TIM1CH2 D1, TIM1CH1 A4
  • Input capture TIM2CH2 A1
  • Output compare TIM2CH1 D13, TIM2CH3 A2, TIM2CH4 A3
  • EXTI: D2, D4, D7, D10
• UART: D0 RX, D1 TX
• SPI: D13 SCK, D12 MISO, D11 MOSI (e.g. for display, memory)
• I2C: D14 SDA, D15 SCL (external peripherals e.g. pressure sensor)
• Optional Neopixel on port D8

For more BSP details see BoardSupportPackageFirefly.

For this sample OCTOPUS OLED display PIS-1277 e.g. from Digikey or Distrelec is used. See also OledDisplay.

Getting Started

These instructions will get you a copy of the project up and running on your local machine (STM32WB Firefly Developer Board) for development and testing purposes.

Prerequisites

• Firefly BLE Development Board with STM32WB55 MCU (Cortex ARM M4) runs at a 32 MHz (the Bluetooth stack runs on a Cortex ARM M0+ core). If you want to debug C and assembler programs you need an ST-Link debugger/programmer e.g. STLINK-V3MINIE.
• Terminal emulator application for PC, e.g.:
  • PuTTY - Windows and Linux
  • Tera Term - Windows
  • Realterm - Windows
  • minicom, microcom, screen - Linux
  • Use the built in Eclipse console (but no LF)

Flash the Mecrisp-Cube binary (MecrispCubeFirefly.bin) or the FS-binary (MecrispCubeFireflyFS.bin, everything included e.g. internal flash drive and Forth utilities) to the Firefly Board.

1. Connect the Firefly Board USB to the PC
2. Hold the BTN button (BOOTP Pin), push the nRST button, release the nRST button
3. Program the binary (MecrispCubeFirefly.bin or MecrispCubeFireflyFS.bin) with the STMCubeProgrammer (select USB Device)
4. Reset or power cycle the Firefly board

Start the terminal emulator application on the PC. Check for the serial communication port (e.g. for Linux /dev/ttyACM0). I set the putty terminal configuration to

• Implicit CR in every LF
• Local echo: Auto
• Local line editing: Auto
• Keyboard Backspace: Control-H
• Keyboard Function: Keys VT100
• Remote character set: CP850

Mecrisp-Stellaris RA 2.5.4 by Matthias Koch.

Mecrisp-Cube 1.5.0 for STM32WB Firefly, 63/128  KiB RAM/FLASH dictionary (C) 2022 peter@spyr.ch
  * Firmware Package STM32Cube FW_WB V1.14.1, USB-CDC, BLE Stack 5.3 (C) 2022 STMicroelectronics
  * CMSIS-RTOS V2 FreeRTOS wrapper, FreeRTOS Kernel V10.3.1 (C) 2020 Amazon.com
  * FatFs for internal flash and microSD - Generic FAT fs module  R0.12c (C) 2017 ChaN
  * tiny vi - part of BusyBox (C) 2000, 2001 Sterling Huxley

include 0:/etc/rc.local
23 5 / .[CR] 4  ok.
: hello ." World" ;[CR]  ok.
hello[CR] World ok.

Special Functions on Startup

USB-CDC is the default console.

Button BTN

start STM bootloader

blue LED

the LED lights up during the initialization phase

Neopixel as Status Indicator

The optional NeoPixel displays the status

dimmed Green

USB enumeration successfull

dimmed Blue

BLE connected

flashing Red

"disk" (serial flash or SD) write operation

flashing Yellow

"disk" (serial flash or SD) read operation

Additional Tools and Local Filesystem

There are two drives available, drive 0: is the flash drive (384 KiB internal flash, see MicroSdBlocks#Flash_Drive) and drive 1: is the microSD drive (optional MicroSdBlocks#SD_Drive).

Populate a microSD with the contents of sdcard. Put the microSD into the uSD Card slot and reset or power cycle the board.

The directory should look like this:

ls -l 1:[CR]
drw-         0 2021-04-18T18:12:38 boot
drw-         0 2021-03-21T18:47:52 etc
drw-         0 2021-03-21T18:47:54 fsr
drw-         0 2021-03-21T18:47:54 home
drw-         0 2021-03-21T18:47:56 man
-rwa      7219 2021-01-08T19:42:36 README.md
ok.

You can use the local CLI commands like mkfs, mkdir and cp to create a filesystem on the serial flash and fill it with files and folders. But this is tedious job because I haven't yet implemented a recursive copy for MecrispCube. But there is prepared disk image (for details see MicroSdBlocks#Serial_Flash) on microSD and the tool dd. You can copy the disk image to the drive 0: (this takes about 2 Minutes):

dd 1:/boot/fd-384k.img 0:[CR]
 ok.
mount 0:[CR]
 ok.
ls 0:[CR]
man                     fsr                     README.md               boot
etc                     home
 ok.

The Mecrisp have some tools bundled in its distribution e.g. assembler, disassembler, dump, float. I put those tools and some more into the folder /fsr. With the "init.fs script" I compile my favorite ones into the flash directory (if you use the FS-binary or util-binary binary, these tools are already compiled in):

compiletoflash[CR]  ok.
include /etc/init.fs[CR]
init.fs Loading started
RAM Dictionary: 392991 KiB
utils.fs loading ...
conditional.fs loading ...
dump.fs loading ...
disassembler-m3.fs loading ...
float.fs loading ...
threads.fs loading ...
RAM Dictionary: 392981 KiB
init.fs finished  ok.

For example, the word disassember is available now:

see dump[CR]
080405F0: B500  push { lr }
080405F2: F7C2  bl  08002A3E  --> cr
080405F4: FA24
080405F6: CF08  ldmia r7 { r3 }
080405F8: F013  ands r2 r3 #F
080405FA: 020F
080405FC: F847  str r3 [ r7 #-4 ]!
080405FE: 3D04
08040600: 2A00  cmp r2 #0
08040602: D000  beq 08040606
08040604: 3610  adds r6 #10
08040606: CF08  ldmia r7 { r3 }
08040608: F847  str r6 [ r7 #-4 ]!

Installing Development Environment

A step by step series of examples that tell you how to get a development env running

Install the IDE STM32CubeIDE, it is Eclipse and GCC based. STM32CubeMX is included in the IDE, you need a stand alone installation only if you do not want to use the STM32CubeIDE.

Get the sources from github:

psi@homer:~> git clone --branch firefly https://github.com/spyren/Mecrisp-Cube
Klone nach 'Mecrisp-Cube' ...
remote: Enumerating objects: 1157, done.
remote: Counting objects: 100% (1157/1157), done.
remote: Compressing objects: 100% (620/620), done.
remote: Total 3183 (delta 720), reused 934 (delta 525), pack-reused 2026
Empfange Objekte: 100% (3183/3183), 41.60 MiB | 6.96 MiB/s, Fertig.
Löse Unterschiede auf: 100% (2100/2100), Fertig.

Import the project into the IDE:

File -> Import -> General -> Existing Projects into Workspace -> Select root directory
Copy project into workspace
Browse to Mecrisp-Cube directory

Generate code from the STM32CubeMX MecrispCubeFirefly.ioc file:

Project -> Generate Code 

Restore changed source files

$ git status
{list of changed files}
$ git restore {files to restore} 

or simpler

$ git stash
$ git drop

Select the Build Configuration (Debug if you want to debug the project) and Build the project:

Project -> Build Configurations -> Set Active -> Debug/Release 
Project -> Build Project

Extensions

Arduino UNO Adaptor

It is a one evening project to solder this adaptor. For the pinout see BoardSupportPackageFirefly#Pinout and the JTAG see BoardSupportPackageFirefly#JTAG_SWD.

• Arduino Proto Shield
• 0.1" pin sockets, e.g. Female Headers, Preci-dip
• 10 or 14 pin 0.05" JTAG/SWD header e.g. Samtec 14 pin FTSH-107-01-L-DV-K-A
• Magnet Wire, 30 AWG, Enameled Copper

DIL#	Descr	Descr'	UNO	UNO'	Pin
1	GND		GND
2	D0	UART_RX	RX	GPIO0	CN4.1
3	D1	UART_TX	TX	GPIO1	CN4.2
4	D2		GPIO2		CN4.3
5	D3		GPIO3		CN4.4
6	D4		GPIO4		CN4.5
7	D5		GPIO5		CN4.6
8	D6		GPIO6		CN4.7
9	D7		GPIO7		CN4.8
10	D8		GPIO8		CN1.1
11	D9		GPIO9		CN1.2
12	D10		GPIO10		CN1.3
13	D11	SPI_MOSI	GPIO11	MOSI	CN1.4
14	D12	SPI_MISO	GPIO12	MISO	CN1.5
15	D13	SPI_CLK	GPIO13	SCK	CN1.6
16	D14	SCL	SCL	GPIO15	CN1.10
17	D15	SDA	SDA	GPIO14	CN1.9
18	A0	D16	A0	GPIO16	CN3.1
19	A1	D17	A1	GPIO17	CN3.2
20	A2	D18	A2	GPIO18	CN3.3
21	A3	D19	A3	GPIO19	CN3.4
22	A4	D20	A4	GPIO20	CN3.5
23	SWCLK
24	SWDIO
25	nRST		RESET		CN2.3
26	3.3V		3.3V		CN2.4
27	GND		GND		CN2.6
28	VIN		VIN		CN2.8

There is a Teensy Arduino Shield Adapter from Sparkfun, but I2C and analog pins are different. You have to modify it.

Adafruit Feather Adaptor

https://learn.adafruit.com/adafruit-feather/feather-specification. You have to adapt the firmware for using the Feather pinout.

There is a Teensy 3.x Feather Adapter from Adafruit, but I2C and analog pins are different. You have to modify it. You can build your own one from scratch by yourself.

• Stacking headers
• FeatherWing Proto
• 0.1" sockets, 2 x 14 e.g. Female Headers, Preci-dip
• Magnet Wire, 30 AWG, Enameled Copper
• optional for debugging .050 Low Profile Tiger Eye IDC Ribbon Cable

JP1 Left, JP3 Right

DIL#	Descr	Descr'	Feather	Feather'	Pin	SWD ST
1	GND		GND		JP1.13	5, 7, 11
2	D0	UART_RX	RX	GPIO0	JP1.3	13
3	D1	UART_TX	TX	GPIO1	JP1.2	14
4	D2		GPIO11		JP3.6
5	D3		GPIO12		JP3.5
6	D4		GPIO13	red LED	JP3.4
7	D5		GPIO5	BUTTONC	JP3.10
8	D6		GPIO6	BUTTONB	JP3.9
9	D7		A5		JP1.7
10	D8		Neopixel
11	D9		GPIO9	BUTTONA	JP3.8
12	D10		GPIO10		JP3.7
13	D11	SPI_MOSI	MOSI	GPIO25	JP1.5
14	D12	SPI_MISO	MISO	GPIO24	JP1.4
15	D13	SPI_CLK	SCK	GPIO23	JP1.6
16	D14	SCL	SCL	GPIO15	JP3.11
17	D15	SDA	SDA	GPIO14	JP3.12
18	A0	D16	A0	GPIO16	JP1.12
19	A1	D17	A1	GPIO17	JP1.11
20	A2	D18	A2	GPIO18	JP1.10
21	A3	D19	A3	GPIO19	JP1.9
22	A4	D20	A4	GPIO20	JP1.8
23	SWDCLK					6
24	SWDIO					4
25	nRST		RESET		JP1.16	12
26	3.3V		3.3V		JP1.15	3
27	GND		GND		JP1.13
28	VIN		USB		JP3.3

2 or 16 MiB QSPI NOR Flash

The only thing I really miss is a serial Flash (like the one the Katydid has). But it is not a big deal to add one.

• Adafruit QSPI DIP Breakout Board W25Q16 2 MByte or W25Q128 16 MByte
• Sparkfun W25Q128 16 MiB
• SPI Flash Memory Add-On for Ladybug or Butterfly