Microprocessors and -controllers

• audiobook of data sheet ATtiny212_412
• recitation
  • presentation
• literature explaining working with AVRs
• microcontroller vs -processor
• download platformio for vscode

MCU

An MCU is a group of microcontroller units that share a common architecture, design, and often the same core features

• ARM Cortex-M is a popular MCU family, where multiple manufacturers like STMicroelectronics, NXP, and Microchip produce MCUs that are based on the ARM Cortex-M core.
• AVR is another MCU family, famously used in the Arduino platform.
• PIC is a family of MCUs from Microchip Technology, with a range of devices from small 8-bit controllers to more powerful 16-bit and 32-bit versions.

Within each MCU family, you’ll typically see models that differ by features like:

• Flash memory size
• RAM size
• Clock speed
• Number of GPIO pins
• Peripheral support (e.g., UART, SPI, I2C, timers, etc.)

In-System Programming (ISP)

• the act of programming a microcontroller while it is already mounted on the board
• Contrary to Pre-Programming. You program the contro

CMSIS-DAP Devices are all devices that can write programs into a microcontroller's memory using JTAG or SWD. ler before soldering it somewhere.

Available Controllers

At least 5 of each:

• SEEEDSTUDIO XIAO SAMD21 NO HDRS
• SEEEDSTUDIO XIAO ESP32C3 NO HDRS
• SEEEDSTUDIO XIAO ESP32S3 NO HDRS
• SEEED STUDIO XIAO RP2040 ARDUINO
• ATSAMD11C14A-SSUT
• ATSAMD21E18A-AUT
• ATTINY412-SSFR
• ATTINY1624-SSFR
• ATTINY3226-SU
• AVR128DB32-I/PT

RP2040 (Raspberry Pi Pico)

Toolchain:

• Primary: Pico SDK (C/C++), CMake
• Alternatives: Arduino IDE (via Arduino-Pico Core), MicroPython/CircuitPython

Workflow:

1. Write code in C/C++ or Python.
2. Build with CMake (Pico SDK) or Arduino IDE.
3. Flash via USB (UF2 bootloader) or SWD debugger (e.g., Picoprobe).

Efficiency Tips:

• Use Visual Studio Code with the Pico SDK extension for CMake integration.
• Leverage Picoprobe (a second Pico) for debugging.

ESP32 (Espressif)

Toolchain:

• Primary: ESP-IDF (C/C++), PlatformIO
• Alternatives: Arduino IDE (via ESP32 Core)

Workflow:

1. Develop in C/C++ (ESP-IDF) or Arduino framework.
2. Build with ESP-IDF CLI or PlatformIO.
3. Flash via USB (esptool.py) or OTA updates.

Efficiency Tips:

• PlatformIO streamlines ESP-IDF/Arduino workflows.
• Use ESP-Prog or JTAG for advanced debugging.

SAMD21/SAMD11 (Atmel/Microchip)

Toolchain:

• Primary: Atmel/Microchip Studio (C/C++)
• Alternatives: Arduino IDE (via SAMD Core)

Workflow:

1. Code in C/C++ (Microchip Studio) or Arduino.
2. Build and flash via USB (UF2 bootloader) or EDBG/SWD.

Efficiency Tips:

• Use Arduino IDE for simplicity; enable verbose upload for debugging.
• For low-level control, use CMSIS libraries in Microchip Studio.

Attiny/AVR128 (AVR Family)

Toolchain:

• Primary: AVR-GCC + AVRdude
• Alternatives: Arduino IDE (via ATTiny Core)

Workflow:

1. Write code in C/C++ or Arduino.
2. Compile with AVR-GCC or Arduino IDE.
3. Flash via ISP programmer (e.g., USBasp, Arduino-as-ISP).

Efficiency Tips:

• Use PlatformIO for project management.
• For tinyAVR (e.g., ATtiny85), optimize code size with -Os compiler flag.

General Workflow Optimization Tips

1. Unified Environments:

   • PlatformIO (VS Code) supports all listed MCUs, reducing toolchain setup time.
   • Arduino IDE (with board managers) simplifies entry-level development.

2. Debugging Tools:

   • SWD/JTAG: Use for RP2040, ESP32, SAMD21 (e.g., Segger J-Link, CMSIS-DAP).
   • Serial Monitor: Essential for ESP32/RP2040 debugging.

3. Version Control:

   • Use git for code management; track dependencies (e.g., submodules for Pico SDK).

4. Automation:

   • Write Makefiles or use PlatformIO scripts for CI/CD pipelines.

QFP mit Beinchen seitlich
TQFP ohne Beinchen
Soic-8 8 Beinchen
Punkt oder Kerbe kennzeichnen Pin 1

Putting code onto it

In-System Programming (ISP)

• the act of programming a microcontroller while it is already mounted on the board
• Contrary to Pre-Programming. You program the contro

CMSIS-DAP Devices are all devices that can write programs into a microcontroller's memory using JTAG or SWD. ler before soldering it somewhere.

Serial Peripheral Interface (SPI)

• A standard synchronous serial communication interface used for short-distance communication between a main device and one or more peripheral devices.
• synchronous (needs clock signal), serial communication
• multiple secondary devices are possible
• full-duplex
• pins:
  • MOSI (main out secondary in)
  • MISO (main in secondary out)
  • SCK (clock)
  • SS (secondary select): select which secondary device to communicate with

Serial Peripheral Data Interface (SPDI)

• do not find any source for it
• Good Article GERMAN

Joint Test Action Group (JTAG)

• eletronics manufacturers committee
• they developed a protocol with the same name
• mostly used for programming ARM cores
• daisy-chaining possible
• pins
  • TMS: mode select
  • TCLK: clock
  • TDO: data out
  • TDI: data in
  • nRESET: reset (optional)

Serial Wire Debug (SWD)

• two-pin variant of the JTAG protocol -> replaced JTAG
• daisy-chaining not possible
• most common on newer ARM chips
• pins:
  • swdio: in/out
  • swclk: clock

Unified Program and Debug Interface (UPDI)

• proprietary
• single-wire,
• bi-directional, half-duplex
• asynchronous
• can use off-the shelf UART adapters
• used to program AVR microcontrollers released since 2016, ATTINY412, ATTINY164.
• more detailed blog article
• debugging is hidden behind a proprietary interface, but even though you can snoop on the protocol with just a serial adapter and even though the large scale structure of the protocol is known too
• even more detailed article
• i did not find out what part of the protocol actually is proprietary and what not.

Difference between microcontroller and -processor

...

Programmierer:

ISP-Programmierer

AVRISP MKII

FabISP

JTAG-Programmierer

ATMEL-ICE

http://pub.fabcloud.io/programmers/summary/