characteristic

• STM32F103C8T6 as master
• The screw stepper motor part in the scrapped optical drive is used as the hardware system framework
• 4988 module as stepper motor driver board
• SG90 servo control pen lift
• Arduino has a source code similar to the engraving machine, transplant it to stm32 to deepen the understanding of the algorithm
• low cost! The scrapped optical drive is 6 yuan x 2 from a certain treasure, the steering gear is 3 yuan, the 4988 certain treasure is 3 yuan x 2, the circuit board is made from a Lichuang board, and the glue is 6 yuan from a certain treasure, a total of 27 yuan

describe

Hardware framework construction

• References[1]: https://www.amobbs.com/thread-5715632-1-1.html?_dsign=6ee89b24
• To use glue, I used AB glue; I happened to have a hacksaw at home; I didn’t have the iron sheet used in the link, so I used Feizhai Happy Water cans and cardboard to fix them with glue.
• Physical picture of hardware framework:

Hardware circuit block diagram

Hardware circuit description

1. power circuit
   • It is powered by a 12V 2A power adapter (the lithium battery will be considered later). The 12V power supply is stepped down to 5V through the 7805 linear voltage regulator circuit, and the 5V voltage is stepped down to 3.3V through the RT9193 circuit.
   • The schematic diagram is as follows:
2. MCU circuit
   • The schematic diagram is as follows:
3. Stepper motor circuit
   • To save trouble, connect MS1, MS2, and MS3 to 5V, that is, set the step to 16 subdivisions, short-circuit SLEEP/ and RESET/, that is, connect them to high level (disabled), and connect DIRECTION, STEP, and ENABLE/ The pinout is connected to the MCU circuit [2].
   • The schematic diagram is as follows:
4. Steering gear circuit
   • When connecting a large capacitor, the main consideration is that the current required when lifting the pen is large, and the capacitor can help provide current.
   • The schematic diagram is as follows:
5. interactive circuit
   • sta is the status indicator light, and the other four are front, rear, left, and right indicator lights; pa/st is the pause/start button, sus is the termination button, and the other four buttons are the front, rear, left, and right buttons.
   • The schematic diagram is as follows:

code design

Later addition