The simple breakout boards are build around a CPU STM8S103F3P6 with 16MHz internal

oscillator, 8kB flash, 1kB RAM, and 640 byte EEPROM. The CPU includes a

UART, SPI, I2C, PWM, 10 bit ADC, 3 timer, and up to 14 I/O pins - quite similar to the Atmel ATmega8.

One (red) LED is connected to GPIO PB5 (CPU pin 11). The push button is for

reset. The CPU runs on 3.3V, a linear regulator is integrated on the

board. The micro USB connector is only for (5V) power supply, the data lines

are not connected.

(pitch 2.54mm, perfect for breadboards).

I am using the ST-Link V2 compatible flash tool in the green plastic

housing. The one in the metal housing uses a different pinout.

Connection to the green flashtool:

|Signal name |CPU board |Flash tool |Metal flash tool

|------ |-----: |-----: |-----:

|3V3 |1 |2 | 7

|SWIM |2 |5 | 5

|GND |3 |7 | 3

|NRST |4 |9 | 1

My breakout boards came preprogrammed with a blink program and with active

write protection bits. For unlocking before first use:

stm8flash -cstlinkv2 -pstm8s103?3 -u

STM8 uses the SWIM protocol, STM32 uses SWD protocol.

| STM8-Board | SWIM-Verbinder P3

| ---------- | -----------------

| 1 | 3V3

| 2 | SWIM (PD1)

| 3 | GND

| 4 | NRST

Discovery STM32F0308 as ST-Link/V2 (SWD only, not usable for the STM8):

|Pin out CN3 | SWD

|----------- | --------------

|1 | ? detect oder so?

|2 |JTCK/SWCLK

|3 |GND

|4 |JTMS/SWDIO

|5 |NRST

|6 |SWO

Pinout of Chinese ST-Link V2-clone with green plasic housing:

+-----+

T_JRST | 1 2| 3V3

5V | 3 4| T_JTCK/T_SWCLK

SWIM 5 6| T_JTMS/T_SWDIO

GND | 7 8| T_JTDO

SWIM RST| 9 10| T_JTDI

+-----+

Pinout of Chinese ST-Link V2-clone with metal housing:

+-----+

RST | 1 2| SWDIO

GND | 3 4| GND

SWIM 5 6| SWCLK

3V3 | 7 8| 3V3

5V | 9 10| 5V

+-----+

For Linux: required lines in /etc/udev/rules.d/99-stlink.rules:

# ST-Link/V2 programming adapter

# ST-Link V1

#SUBSYSTEM=="usb", ENV{DEVTYPE}=="usb_device",

ATTR{idVendor}=="0483", ATTR{idProduct}=="3744", MODE="0666", GROUP="plugdev"

# ST-Link/V2, the china adapter with the green plastic housing

#SUBSYSTEM=="usb", ENV{DEVTYPE}=="usb_device", ATTR{idVendor}=="0483", ATTR{idProduct}=="3748", MODE="0666"

ATTR{idVendor}=="0483", ATTR{idProduct}=="3748", MODE="0666", GROUP="plugdev"

I discuss some possible pin mapping and check how close we could get the the

ideal mapping. Unfortunatly, it turns out that a perfect mapping is not

possible.

Some internal details can be influenced by setting compile-time defines

using the `CFLAGS=-Dflagname` line in the Makefile.

Compile-time flag | Purpose

----------------- | --------

`SUPPORT_ALTERNATE_MAPPINGS` | Allow the use of `alternateFunctions()`

`ENABLE_SWIM` | Do not disable the remote debugging

function on the SWIM pin. This means that this pin can not be used for

normal I/O functions.

`USE_SPL` | Use SPL functions for I/O access instead

of direct register accesses. Useful only for debugging and porting to other

CPU variants. Do not use for regular development.

`` |

`` |

`` |

timer1: PWM for PC6, PC7 (8,9), could be used for ADC

timer2: PWM for PA3 (2)

timer4: millis()

the prescaler is initialised for an ADC clock in the range of 1..2 MHz. The

minimum prescaler value is 2, so for a clock speed of less than 2 MHz the

required minimum ADC clock frequency can not be reached anymore.

Die ganze Pin->Portadressen-Arithmetik könnte komlett entrümpelt werden. Statt

Tabellen fest im Code enthalten.

`digitalWrite` wird spektakulär umständlich übersetzt. Hier lohnt sich

Handassembler.

Added `alternateFunction()` to allow switching of some pins to their alternate

functions. This allows for three more PWM pins, but maybe it adds to much

complexity for the Arduino API. Not sure if it should stay. Has to be

enabled by defining `SUPPORT_ALTERNATE_MAPPINGS`.

**Input-Capture-Mode:** Available for all four channels, at least for timer1. Would be great for precise time measurements. Maybe build a library?

**Encoder interface mode:** Kann von Haus aus mit Quadratur-Encodern umgehen

und in Hardware zählen -> perfekt für die Druckerschlitten-Motorsteuerung.