You signed in with another tab or window. Reload to refresh your session.You signed out in another tab or window. Reload to refresh your session.You switched accounts on another tab or window. Reload to refresh your session.Dismiss alert
Copy file name to clipboardExpand all lines: website/versioned_docs/version-acs_cc/project/2026/horatiu.oprea/index.md
+27-11Lines changed: 27 additions & 11 deletions
Display the source diff
Display the rich diff
Original file line number
Diff line number
Diff line change
@@ -20,35 +20,47 @@ Embedded systems and control theory are two domains I wanted to explore simultan
20
20
21
21
## Architecture
22
22
23
-
The system is structured around four main architectural components that form a closed control loop:
23
+
The system is structured around 4 main architectural components that form a closed control loop:
24
24
25
25
**Sensor** — The VL53L0X laser Time-of-Flight sensor is mounted at the top of the tube and measures the distance to the ball via I2C. This gives the current height y(t).
26
26
27
27
**Controller** — The STM32 Nucleo-U545RE-Q runs the PID algorithm in an Embassy async task at a fixed 20ms cycle. It reads the current height from the sensor, computes the error relative to the target, and produces a control output u(t) in the range 0–100%.
28
28
29
29
**Actuator** — The Delta PFB0412EN-E fan receives a PWM signal at 25kHz directly on its dedicated blue wire. The duty cycle of this signal determines the fan speed, which controls the airflow and thus the ball's position.
30
30
31
-
**User Interface** — Four potentiometers provide analog inputs via ADC: one sets the target height, and three adjust Kp, Ki, Kd in Manual mode. A 1602 I2C LCD displays system state. A toggle switch selects between Auto and Manual mode.
31
+
**User Interface** — Four potentiometers provide analog inputs via ADC: one sets the target height in Auto Mode, and three adjust Kp, Ki, Kd in Manual mode. A ST7920 LCD displays system state using SPI. A toggle switch selects between Auto and Manual mode.
The project uses an STM32 Nucleo-U545RE-Q (Cortex-M33) as the main microcontroller, programmed in Rust with the Embassy async framework. The VL53L0X laser ToF sensor communicates over I2C and provides distance measurements with millimeter precision. The Delta PFB0412EN-E axial fan (40x40x28mm, 12V) features a native PWM control input, allowing direct speed control from the STM32 without a MOSFET driver stage. Four 10kΩ potentiometers provide analog inputs for height target and PID tuning. A 1602 LCD with I2C backpack shares the I2C bus with the sensor. A toggle switch selects the operating mode. The fan is powered by a dedicated 12V DC adapter; the STM32 and all logic components are powered via USB (5V), with the onboard regulator supplying 3.3V to the sensor and potentiometers. All grounds are tied to a common reference on the breadboard.
48
60
49
61
### Schematics
50
62
51
-
_KiCad schematic to be added here in SVG format._
63
+

52
64
53
65
### Bill of Materials
54
66
@@ -57,10 +69,10 @@ _KiCad schematic to be added here in SVG format._
57
69
|[STM32 Nucleo-U545RE-Q](https://www.st.com/en/evaluation-tools/nucleo-u545re-q.html)| Main microcontroller — runs PID algorithm in Rust/Embassy | already owned |
58
70
|[VL53L0X Laser ToF Sensor](https://www.optimusdigital.ro/ro/senzori-senzori-de-distanta/3309-modul-senzor-de-distanta-cu-laser-vl53l0x.html)| Measures ball height inside the tube via I2C |[25 RON](https://www.optimusdigital.ro)|
59
71
|[Delta PFB0412EN-E Fan 12V](https://www.digikey.com)| Propeller fan — controls airflow in the tube via PWM | already owned |
60
-
|[LCD 1602 I2C](https://www.optimusdigital.ro/ro/optoelectronice-lcd-uri/2894-lcd-cu-interfata-i2c-si-backlight-albastru.html)| Displays current height and PID constants |[15 RON](https://www.optimusdigital.ro)|
72
+
|[LCD ST7920](https://www.optimusdigital.ro/ro/optoelectronice-lcd-uri/2894-lcd-cu-interfata-i2c-si-backlight-albastru.html)| Displays current height and PID constants |[15 RON](https://www.optimusdigital.ro)|
61
73
| Potentiometer 10kΩ (x4) | Height target (x1) + Kp, Ki, Kd tuning (x3) |[5 RON x4](https://www.optimusdigital.ro)|
| Breadboard MB102 + YuRobot power module| Prototyping platform with integrated power supply |[20 RON](https://www.optimusdigital.ro)|
75
+
| Breadboard MB102 - 830 pins| Prototyping platform with integrated power supply |[20 RON](https://www.optimusdigital.ro)|
64
76
| DC Jack Module 5.5x2.1mm (breadboard) | Connects 12V adapter to breadboard for fan power |[7 RON](https://www.optimusdigital.ro)|
65
77
| Resistor 100Ω | Protects STM32 PWM pin from fan input impedance |[1 RON](https://www.optimusdigital.ro)|
66
78
| Jumper Wire Kit (120 pcs) | All signal and power connections on breadboard |[15 RON](https://www.optimusdigital.ro)|
@@ -75,12 +87,16 @@ _KiCad schematic to be added here in SVG format._
75
87
|[embassy-stm32](https://github.com/embassy-rs/embassy)| Async HAL for STM32 microcontrollers | Peripheral access: PWM, I2C, ADC, GPIO |
76
88
|[embassy-executor](https://github.com/embassy-rs/embassy)| Async task executor for embedded systems | Runs sensor, control and display tasks concurrently |
77
89
|[embassy-time](https://github.com/embassy-rs/embassy)| Timers and delays for Embassy | Fixed 20ms control loop timing |
90
+
|[embassy-spi](https://github.com/UPB-PMRust/lab-solutions/tree/main/lab05)| Driver for ST7920-based LCD displays | Renders height and PID values |
78
91
|[vl53l0x](https://crates.io/crates/vl53l0x)| Driver for VL53L0X ToF sensor | Reads ball distance over I2C |
79
-
|[hd44780-driver](https://crates.io/crates/hd44780-driver)| Driver for HD44780-based LCD displays | Renders height and PID values on 1602 LCD |
80
92
|[defmt](https://github.com/knurling-rs/defmt)| Efficient logging framework for embedded Rust | Debug output during development via RTT |
81
93
|[defmt-rtt](https://github.com/knurling-rs/defmt)| RTT transport for defmt | Sends log messages to host over USB |
82
94
|[panic-probe](https://github.com/knurling-rs/panic-probe)| Panic handler for embedded Rust | Reports panics via defmt |
83
95
96
+
## Closed Control Loop
97
+
98
+

99
+
84
100
## Links
85
101
86
102
1.[Embassy — Async framework for embedded Rust](https://embassy.dev)
0 commit comments