Features

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

• 63 KiB RAM dictionary
• 128 KiB Flash Forth dictionary
• 50 KiB for C code
• Internal Flash drive 0:, 384 KiB (for details see Nucleo)
• Serial console UART / USB CDC / BLE
• microSD drive 1:
• Control (5-button joystick, Back button, Reboot)

Not supported yet:

• LCD display 128x64 pixel
• Power (LIPO charger)
• GPIO
• RGB LED
• Sub-1 GHz Transceiver
• 125kHz RFID
• NFC
• Infrared Transceiver
• iButton
• Buzzer
• Vibration Motor

For more BSP details see BoardSupportPackageFlipper.

Getting Started

These instructions will get you a copy of the project up and running on your local machine Flipper Zero) for development and testing purposes.

Prerequisites

• Flipper Zero with STM32WB55 MCU (Cortex ARM M4) runs at a 32 MHz (the Bluetooth stack runs on a Cortex ARM M0+ core). ST-Link debugger/programmer is integrated on board.
• 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 (MecrispCubeFlipper.bin) or the util-binary (MecrispCubeFlipperUtil.bin) to the Discovery Board.

1. Connect the Flipper Zero USB to the PC
2. Hold the xx button (BOOTP Pin), push the nRST button, release the nRST button
3. Program the binary (MecrispCubeFlipper.bin or MecrispCubeFlipperFS.bin) with the STMCubeProgrammer (select USB Device)
4. Reset or power cycle the Flipper Zero

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 Discovery, 63/384  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 1

CRS (Bluetooth Cable Replacement Service) is standard console

Button 2

UART is standard console

RGB LED as Status Indicator

The RGB LED 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

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 8 Minutes):

dd 1:/boot/fd-1MiB.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 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 WB5M 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 MecrispCubeWB5M.ioc file:

Project -> Generate Code 

Restore changed source files

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

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