205 lines
7.8 KiB
Markdown
205 lines
7.8 KiB
Markdown
# SSD1306 OLED Servo Control with STM32 Blue Pill
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This project demonstrates how to control a servo motor using an IBT_2 (BTS7960) motor driver, an STM32 Blue Pill, and a 128x64 SSD1306 OLED display. The user can control the motor's speed and direction using four push buttons, with real-time feedback on the OLED screen. It shows how to use the DAPLink programmer in Arduino IDE v2 with debugging.
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## Features
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* **Motor Control:** Adjust speed and direction of a servo motor.
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* **OLED Display:** A 128x64 SSD1306 OLED display shows the current speed, direction, and motor state (ON/OFF).
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* **User Interface:** A simple and intuitive interface with four buttons for control (Up, Down, OK, Cancel).
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* **Two-Color Display Optimization:** The UI is designed for two-color (Yellow and Blue) OLED displays, with a static header in the yellow section and dynamic values in the blue section.
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## Hardware Required
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* STM32F103C8T6 "Blue Pill" development board
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* 128x64 SSD1306 OLED display (I2C) with 4 push buttons (up, down, OK, Back)
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* IBT_2 (dual BTS7960) motor driver
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* Servo motor e.g.: RS-550 or R-775
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* External power supply for the motor 12-24V/5A
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* Breadboard and jumper wires
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## Wiring
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Connect the components to the Blue Pill as described below.
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### OLED Display (I2C)
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| OLED Display Pin | Blue Pill Pin |
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| :--------------- | :------------ |
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| VCC | 3.3V |
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| GND | GND |
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| SCL | PB6 |
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| SDA | PB7 |
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### Control Buttons
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The buttons are connected to GPIO pins using the internal pull-up resistors. The other terminal of each button should be connected to GND.
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| Button Function | Blue Pill Pin |
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| :-------------- | :------------ |
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| Up | PA0 |
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| Down | PA1 |
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| OK | PA2 |
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| Cancel | PA3 |
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### IBT_2 Motor Driver
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The IBT_2 module requires its own power supply for the motor.
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| IBT_2 Pin | Blue Pill Pin | Description |
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| :-------- | :------------ | :--------------------------- |
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| VCC | 5V | Logic Power |
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| GND | GND | Logic Ground |
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| R_EN | 3.3V | Right Enable (connect to 3.3V) |
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| L_EN | 3.3V | Left Enable (connect to 3.3V) |
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| RPWM | PB0 | Right PWM Signal (Forward) |
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| LPWM | PB1 | Left PWM Signal (Reverse) |
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### DAPLink UART
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For debugging and logging, you can connect the DAPLink's virtual COM port to the Blue Pill's UART1.
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| DAPLink Pin | Blue Pill Pin | Description |
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| :---------- | :------------ | :------------------ |
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| RXD | PA9 (TX1) | Connect to TX |
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| TXD | PA10 (RX1) | Connect to RX |
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| GND | GND | Common Ground |
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**IBT_2 Power Connections:**
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| IBT_2 Terminal | Connection |
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| :------------- | :----------------------------- |
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| B+ | Positive of Motor Power Supply |
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| B- | Negative of Motor Power Supply |
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| M+ | Positive of Servo Motor |
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| M- | Negative of Servo Motor |
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## Dependencies
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This sketch requires the following Arduino libraries:
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* `Wire`
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* `Adafruit_GFX`
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* `Adafruit_SSD1306`
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* `Adafruit_BusIO` (A dependency for the Adafruit libraries)
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## Getting Started
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### Prerequisites
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* [Arduino CLI](https://arduino.github.io/arduino-cli/installation/)
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* [STMicroelectronics STM32 core](https://github.com/stm32duino/Arduino_Core_STM32)
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### Installation
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1. **Install arduino-cli:** Follow the official instructions at [arduino.github.io/arduino-cli/installation/](https://arduino.github.io/arduino-cli/installation/).
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2. **Initialize and Configure arduino-cli:**
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* Create a default configuration file:
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```bash
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arduino-cli config init
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```
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* Add the STMicroelectronics board manager URL:
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```bash
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arduino-cli config add board_manager.additional_urls https://github.com/stm32duino/BoardManagerFiles/raw/main/package_stmicroelectronics_index.json
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```
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* Update the local core index:
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```bash
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arduino-cli core update-index
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```
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* Install the STM32 core:
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```bash
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arduino-cli core install STMicroelectronics:stm32
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```
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3. **Install Required Libraries:**
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```bash
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arduino-cli lib install "Adafruit SSD1306" "Adafruit GFX Library" "Adafruit BusIO"
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```
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## Board Setup
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In Arduino IDE → Tools, set:
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Board → STM32 MCU based boards → Generic STM32F1 series
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Board part number → BluePill F103CB (or C8 with 128K)
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Upload Method → OpenOCD DAPLink (SWD)
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## Compilation
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1. **Prepare Your Sketch Directory:** Ensure your sketch file is named `SSD1306_sketch.ino` and is located in a folder with the same name. For example:
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`/path/to/your/project/SSD1306_sketch/SSD1306_sketch.ino`
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2. **Compile the Sketch:** Compile the sketch for the Blue Pill (STM32F103CB or C8 with 128k), specifying the OpenOCD upload method.
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```bash
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arduino-cli compile --fqbn STMicroelectronics:stm32:GenF1:pnum=BLUEPILL_F103CB,upload_method=OpenOCDDapLink /path/to/your/project/SSD1306_sketch
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```
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The binary files will be generated in a temporary build directory. To find the path to the binary, you can run the compile command with the `--verbose` flag.
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## Upload to the Board
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The compiled sketch can be uploaded to the Blue Pill using `openocd`. The exact command may vary depending on your setup.
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First, you need to find the path to your compiled `.elf` file. You can find this in the output of the `arduino-cli compile` command. It will be in a temporary directory `~/.cache/arduino/sketches`.
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Then, find the `openocd` e.g.: `~/.arduino15/packages/STMicroelectronics/tools/xpack-openocd/0.12.0-6/bin/openocd` or install a distro specific version e.g.: `sudo apt install openocd`. Example of the path to the compiled sketch: `/home/martin/.cache/arduino/sketches/96DBB1C909C240C2F96DCDD5DDFB9A12/SSD1306_sketch.ino.elf`
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Here is an example command to upload the sketch using DAPLink:
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```bash
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/path/to/your/openocd -d2 -f interface/cmsis-dap.cfg -f target/stm32f1x.cfg -c "program {/path/to/your/sketch.ino.elf} verify reset exit"
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```
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## 🐞 Hardware Debugging with DAPLink (CMSIS-DAP) on Blue Pill
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This section describes how to enable **hardware debugging** for the STM32F103 "Blue Pill" board using a **DAPLink / CMSIS-DAP** debugger in **Arduino IDE 2**.
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By default, the STM32 Arduino core loads the wrong OpenOCD configuration (`dapdirect_swd`, meant for ST-Link).
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Until the [issues/2807](https://github.com/stm32duino/Arduino_Core_STM32/issues/2807) is not fixed, follow these steps to work around it:
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### 🧭 1. Locate STM32 Core Folder (Linux)
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Open a terminal and navigate to your STM32 Arduino core installation:
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```bash
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cd ~/.arduino15/packages/STMicroelectronics/hardware/stm32/2.11.0/
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```
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Adjust the version number if different (check in Arduino IDE → Tools → Board → Boards Manager).
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🧰 2. Create or Edit `platform.local.txt`
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Create (or edit) a local override file:
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```bash
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nano platform.local.txt
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```
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Paste the following lines:
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```bash
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debug.server.openocd.scripts.0=interface/cmsis-dap.cfg
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debug.server.openocd.scripts.1={runtime.platform.path}/debugger/select_swd.cfg
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```
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Save and close (Ctrl + O, Enter, Ctrl + X).
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These lines tell OpenOCD to:
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- Use the CMSIS-DAP interface `interface/cmsis-dap.cfg`
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- Use standard SWD transport `select_swd.cfg` instead of `dapdirect_swd`
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🔁 3. Restart Arduino IDE
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Completely close and reopen Arduino IDE 2 to apply the new settings.
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⚙️ 4. Configure the IDE
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In Arduino IDE → Tools, set:
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- Debug symbols and core logs → Core Logs and Symbols Enabled (-g)
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- Optimize → Debug (-Og)
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Then click the 🐞 Debug icon and press Start Debugging. |