sensorless_homing/
sensorless_homing.rs

1//! Sensorless homing example for TMC2209.
2//!
3//! This example demonstrates how to use StallGuard for sensorless homing,
4//! allowing the motor to detect when it hits a mechanical endstop without
5//! requiring physical limit switches.
6
7#![allow(unused)]
8
9use tmc2209_uart::{MicrostepResolution, Tmc2209};
10
11/// Perform sensorless homing using StallGuard.
12///
13/// # Important Notes
14///
15/// 1. StallGuard works best in SpreadCycle mode
16/// 2. The motor must be moving above the TCOOLTHRS velocity
17/// 3. Use moderate speeds for reliable detection
18/// 4. Tune SGTHRS for your specific motor and mechanics
19#[cfg(feature = "blocking")]
20fn sensorless_homing<U, E>(uart: U) -> Result<(), tmc2209_uart::Error<E>>
21where
22    U: embedded_io::Read<Error = E> + embedded_io::Write<Error = E>,
23{
24    let mut driver = Tmc2209::new(uart, 0);
25
26    // =========================================================================
27    // Step 1: Basic Configuration
28    // =========================================================================
29
30    // Set appropriate current for homing (usually lower than running current)
31    driver.set_current(12, 6, 4)?;
32
33    // Use lower microstep resolution for more reliable stall detection
34    driver.set_microsteps(MicrostepResolution::M16)?;
35
36    // =========================================================================
37    // Step 2: Configure StallGuard
38    // =========================================================================
39
40    // CRITICAL: Use SpreadCycle mode for StallGuard
41    driver.enable_spreadcycle()?;
42
43    // Configure stall detection
44    driver.configure_stall_detection(50)?;
45
46    // Set TCOOLTHRS - StallGuard is only active when TSTEP < TCOOLTHRS
47    driver.set_coolstep_threshold(0xFFFFF)?;
48
49    driver.set_enabled(true)?;
50
51    // =========================================================================
52    // Step 3: Perform Homing
53    // =========================================================================
54
55    // Move towards the endstop
56    let homing_velocity = -2000i32;
57    driver.set_velocity(homing_velocity)?;
58
59    // Poll for stall detection
60    let max_iterations = 10000u32;
61
62    for _ in 0..max_iterations {
63        if driver.is_stalled()? {
64            break;
65        }
66        // Add platform-specific delay here
67    }
68
69    // Stop the motor immediately
70    driver.stop()?;
71
72    // =========================================================================
73    // Step 4: Post-Homing Configuration
74    // =========================================================================
75
76    // Switch back to StealthChop for quiet operation
77    driver.enable_stealthchop()?;
78
79    // Restore normal running current
80    driver.set_current(20, 10, 6)?;
81
82    Ok(())
83}
84
85/// Alternative: Home in both directions to find center.
86#[cfg(feature = "blocking")]
87fn home_to_center<U, E>(uart: U) -> Result<(), tmc2209_uart::Error<E>>
88where
89    U: embedded_io::Read<Error = E> + embedded_io::Write<Error = E>,
90{
91    let mut driver = Tmc2209::new(uart, 0);
92
93    // Configure for homing
94    driver.set_current(12, 6, 4)?;
95    driver.enable_spreadcycle()?;
96    driver.configure_stall_detection(50)?;
97    driver.set_coolstep_threshold(0xFFFFF)?;
98    driver.set_enabled(true)?;
99
100    // Home to minimum position
101    driver.set_velocity(-2000)?;
102    while !driver.is_stalled()? {
103        // Wait or add timeout
104    }
105    driver.stop()?;
106    let _min_position = 0i32;
107
108    // Home to maximum position
109    driver.set_velocity(2000)?;
110    let mut step_count = 0i32;
111    while !driver.is_stalled()? {
112        step_count += 1;
113    }
114    driver.stop()?;
115    let max_position = step_count;
116
117    // Move to center
118    let _center = max_position / 2;
119    driver.set_velocity(-2000)?;
120    // Move for half the counted steps
121    driver.stop()?;
122
123    Ok(())
124}
125
126fn main() {
127    println!("TMC2209 Sensorless Homing Example");
128    println!("This example shows how to use StallGuard for sensorless homing.");
129}
sensorless_homing/sensorless_homing.rs

sensorless_homing/
sensorless_homing.rs
