setup fliplink

.cargo/config.toml

@@ -1,6 +1,10 @@
 [target.'cfg(all(target_arch = "arm", target_os = "none"))']
 runner = "probe-rs run --chip STM32F411VETx"
 
+# flip-link: zero-cost stack-overflow protection. It wraps the real linker
+# (LLD here), so it stays compatible with the -Tlink.x / -Tdefmt.x args below.
+linker = "flip-link"
+
 rustflags = [
   # LLD (shipped with the Rust toolchain) is used as the default linker
   "-C", "link-arg=-Tlink.x",

Cargo.toml

@@ -6,7 +6,7 @@ edition = "2024"
 [dependencies]
 # board support: re-exports the HAL as `f411::hal`, plus the L3gd20/Lsm303dlhc
 # interfaces and the `led` module
-f411 = { path = "../f411" }
+f411 = { path = "../code/f411" }
 
 cortex-m = "0.7.7"
 cortex-m-rt = "0.7.5"

justfile

@@ -0,0 +1,59 @@
+# kttl — STM32F411 kettle controller
+# Run `just` to list recipes.
+
+# udev rules shipped with this repo (probe-rs probe permissions on Linux)
+rules_src := "etc/69-probe-rs.rules"
+rules_dst := "/etc/udev/rules.d/69-probe-rs.rules"
+
+# Default: show available recipes
+default:
+    @just --list
+
+# One-shot dev setup: install toolchain bits + probe permissions
+setup: install-tools probe-setup
+    @echo "Setup complete. Plug in the probe (re-plug if it was already connected)."
+
+# Install the Rust target and the host tools this project links/flashes with
+install-tools:
+    rustup target add thumbv7em-none-eabihf
+
+# Set up probe-rs probe access on Linux: install udev rules + reload
+# https://probe.rs/docs/getting-started/probe-setup/
+probe-setup:
+    @echo "Installing udev rules -> {{rules_dst}} (needs sudo)"
+    sudo install -m 0644 {{rules_src}} {{rules_dst}}
+    sudo udevadm control --reload
+    sudo udevadm trigger
+    @# plugdev group is referenced by the rules; create it and add the user if missing
+    sudo groupadd --system plugdev 2>/dev/null || true
+    sudo usermod -aG plugdev "$USER"
+    @echo "If the probe was already plugged in, unplug and reconnect it."
+    @echo "A new group membership requires a fresh login to take effect."
+
+# List debug probes probe-rs can see (verifies setup worked)
+probes:
+    probe-rs list
+
+# Build the firmware (debug)
+build:
+    cargo build
+
+# Build optimized
+release:
+    cargo build --release
+
+# Flash + run on the target, streaming defmt logs over RTT
+run:
+    cargo run --release
+
+# Compile checks / lints / format
+check:
+    cargo check
+clippy:
+    cargo clippy
+fmt:
+    cargo fmt
+
+# Remove build artifacts
+clean:
+    cargo clean

kttl-analog-wiring.md

@@ -0,0 +1,202 @@
+# kttl — Analog Control Prototype Wiring (LM35 sensor)
+
+Fully-analog temperature controller for a kettle, styled after a Soviet
+radiometer panel. No MCU: a comparator loop reaches/holds a rotary-selected
+target, a moving-coil meter shows live temperature on a **linear 0–100 °C
+dial**, and a solenoid-struck keyswitch clicks (Geiger-style) on each heater
+cycle.
+
+Sensor is an **LM35** (10 mV/°C, linear) — chosen so the dial is truly linear
+and the setpoint ladder is evenly spaced.
+
+> **Status:** prototype / paper design. A few values depend on measuring the
+> actual meter movement and solenoid — see *Open Unknowns*.
+
+---
+
+## 1. Panel controls
+
+| Ref | Control            | Type                 | Function                                  | Domain      |
+|-----|--------------------|----------------------|-------------------------------------------|-------------|
+| SW1 | Rotary selector    | 6-position, 1 wafer  | Target temp tap (60/70/80/85/90/100 °C)   | low-voltage |
+| SW2 | Rocker (on/off)    | SPST                 | **Heater enable only** (not master power) | low-voltage |
+| SW3 | Hold toggle        | SPDT                 | After target: HOLD (cycle) vs ONE-SHOT    | low-voltage |
+| M1  | Moving-coil meter  | µA/mA movement (М205)| Live temperature, linear 0–100 °C         | always-on   |
+
+Mains is live whenever plugged in. Electronics + meter sit on an **always-on
+rail**; the heater is gated downstream and switched only by the relay/SSR
+(mains-last). The rocker just **stops heating** — it is not a master cut-off.
+
+---
+
+## 2. Power tree
+
+```
+   MAINS (live when plugged in)
+     ├─────────► PSU (mains→5V, always on) ──► +5V rail ─┬─► LM35, comparator, latch,
+     │                                                   │   meter driver, clicker logic
+     │                                                   └─► VREF_PRECISE (LM4040-2.5)
+     │                                                       → setpoint ladder
+     │
+     └─► HEATER PATH (mains):  F1 fuse ─► TC1 thermal cutoff ─► K1/SSR1 ─► ELEMENT
+                                                                  ▲
+                                  enable = SW2(rocker) AND logic-heat
+```
+
+**Note:** the ladder reference is now a **precision reference (not ratiometric)**
+because the LM35 output is an absolute voltage (10 mV/°C). The 5 V rail no longer
+needs to be accurate, but VREF_PRECISE does.
+
+---
+
+## 3. Schematic (block + signal level)
+
+```
+        +5V (always on)                         VREF_PRECISE = 2.500V (LM4040-2.5)
+            │                                              │
+     ┌──────┴──────┐                              ┌────────┴────────┐
+     │  LM35        │  OUT = 10mV/°C               │ SETPOINT LADDER │
+     │  Vs  OUT  GND│  (0°C=0V, 100°C=1.00V)       │ R1..R7 (taps=°C)│
+     └───┬───┬───┬──┘                              └────────┬────────┘
+         │   │   └─GND                                      │ taps: 0.60/0.70/0.80/
+         │   │                                              │       0.85/0.90/1.00 V
+         │   ├─────────────┬──────────────┐         ┌───────┴───────┐
+         │   │             │              │         │ SW1 rotary 6-pos│
+      [Rpd 18k             │              │         └───────┬───────┘
+       to GND]        (to meter      (to comparator −)      │ common = selected Vref
+         │            driver U3)          │          R_in 10k │
+        GND                               │            │      │
+                                          ▼            ▼      │
+                                    ┌──────────────────────┐  │
+                                    │  U1 COMPARATOR LM393 │  │ Rf 2.4M
+                                    │  (−) LM35    (+) tap  │◄─┴──── hysteresis
+                                    │              OUT      ├──┬──── (to +) ~±1°C
+                                    └──────────────────────┘  │
+                                       OUT HIGH = cold         │ on→off edge = "reached"
+                                       (pull-up 10k to +5V)    │
+                                ┌──────────────────────────────┴──┐
+                                │                                  │
+                                ▼                                  ▼
+                        ┌──────────────┐                  ┌────────────────┐
+                        │ U2 CD4013    │                  │ CLICKER one-shot│
+                        │ D-FF latch   │                  │ → Q1 MOSFET     │
+                        │ D=Hi         │                  │ → L1 solenoid   │
+                        │ CLK=reached  │                  │   (+ D1 flyback)│
+                        │ CLR=POR + SW1│                  │ strikes keyswitch│
+                        │        Q' ───┼──┐               └────────────────┘
+                        └──────────────┘  │
+                                          ▼
+                  SW3 HOLD ──────► ┌───────────────┐
+                  (HOLD: force Hi; │ ENABLE gate   │
+                   1-SHOT: use Q') │ (AND)         │
+                                   └──────┬────────┘
+                                          │ heater-want
+                                  SW2 rocker (series)
+                                          │
+                                          ▼
+                                   ┌──────────────┐
+                                   │ Q2 ─► K1/SSR1│  switches MAINS to ELEMENT
+                                   └──────┬───────┘  (via F1 + TC1, mains-last)
+                                          ▼
+                                       ELEMENT
+
+   METER BRANCH:
+        LM35 OUT ─► U3 (op-amp + transistor current sink, Re) ─► M1
+                    I_meter = V_LM35 / Re      (no offset: 0°C = 0V)
+                    linear 0–100 °C dial
+```
+
+---
+
+## 4. Component values
+
+### 4.1 Sensor — LM35
+- **U_LM35:** LM35 (or LM35DZ), Vs = +5 V, OUT = 10 mV/°C.
+  - 0 °C → 0.000 V, 60 °C → 0.600 V, 100 °C → 1.000 V.
+- **Rpd:** ~18 kΩ from OUT to GND (lets the output pull down toward 0 V; basic
+  LM35 only *sources* current). True 0 °C reading needs a negative rail; with a
+  GND pull-down it reads reliably from ~+2 °C up — fine for a kettle.
+- Seal the sensor against water/steam (it's a 3-pin active part, not a bead).
+
+### 4.2 Precision reference + setpoint ladder
+- **VREF_PRECISE:** LM4040-2.5 (2.500 V shunt reference) + bias resistor from
+  +5 V (e.g. ~2.7 kΩ). Absolute accuracy now matters (not ratiometric).
+- Ladder GND → 2.500 V; SW1 taps land on the LM35 setpoint voltages:
+
+| Ref | Segment              | Calc.   | Use (E96/std) |
+|-----|----------------------|---------|---------------|
+| R1  | GND → 60 °C (0.60 V) | 6.00 kΩ | 6.04 kΩ       |
+| R2  | 60 → 70 °C           | 1.00 kΩ | 1.00 kΩ       |
+| R3  | 70 → 80 °C           | 1.00 kΩ | 1.00 kΩ       |
+| R4  | 80 → 85 °C           | 0.50 kΩ | 499 Ω         |
+| R5  | 85 → 90 °C           | 0.50 kΩ | 499 Ω         |
+| R6  | 90 → 100 °C          | 1.00 kΩ | 1.00 kΩ       |
+| R7  | 100 °C (1.00 V) → ref| 15.0 kΩ | 15.0 kΩ       |
+| RT  | master cal trim      | —       | 500 Ω 10-turn (series w/ R7) |
+
+Ladder current ≈ 100 µA. Setpoint voltages = temp × 10 mV/°C — clean and even.
+
+### 4.3 Comparator + hysteresis
+- **U1:** LM393. LM35 OUT → (−); SW1 tap → (+) via **R_in = 10 kΩ**.
+  OUT HIGH = cold = heater wanted. Pull-up 10 kΩ on OUT to +5 V.
+- **Rf:** 2.4 MΩ from OUT to (+) → maintain band ≈ ±1 °C (R_in/Rf · Vout_swing).
+  Band varies slightly with selected tap impedance.
+
+### 4.4 Mode latch (one-shot vs hold)
+- **U2:** CD4013 D flip-flop. D = HIGH. CLK = comparator on→off ("reached") edge
+  (RC-debounce if it chatters). CLR = power-on-reset cap **and** SW1 common
+  (changing temp re-arms). Q′ → enable gate.
+- **SW3 (Hold):**
+  - HOLD → forces enable gate's 2nd input HIGH (latch bypassed → cycles forever).
+  - ONE-SHOT → enable uses Q′ (heater latches OFF after first reach).
+  - Wire SW3 to also pulse CLR so flipping to HOLD resumes cycling.
+
+### 4.5 Heater drive
+- Enable gate (heater-want) AND **SW2 rocker** (series) → **Q2** (small MOSFET) →
+  relay coil **K1** (with flyback diode) *or* **SSR1** control input.
+- K1/SSR1 switches mains to the element, downstream of **F1 (fuse)** and **TC1
+  (independent thermal cutoff)**.
+
+### 4.6 Clicker
+- Comparator on→off edge → one-shot pulse → **Q1** (logic-level MOSFET) → **L1**
+  mini push-pull solenoid (5 V, ~3.5 mm stroke, Adafruit 2776 class) + **D1**
+  flyback diode. Plunger strikes a tactile keyswitch (switch gives the click +
+  bump; pick the strike target/resonator for pitch).
+- HOLD → ticks each maintain cycle; ONE-SHOT → single tick. Add jitter to the
+  pulse for Geiger-style randomness instead of metronomic ticking.
+
+### 4.7 Meter driver
+- **U3:** op-amp + transistor current sink. LM35 OUT → op-amp (+); meter in the
+  collector/drain; Re in emitter/source. `I_meter = V_LM35 / Re`, independent of
+  coil resistance. **No offset stage** (0 °C already = 0 V).
+- Re by movement: **1 mA → Re = 1.00 kΩ**; **100 µA → Re = 10.0 kΩ**.
+- Dial is **linear 0–100 °C** — re-letter the М205 face 0→100.
+
+---
+
+## 5. Safety notes
+- **SW1/SW2/SW3 are all low-voltage.** No panel switch carries element current;
+  mains is switched only by K1/SSR1 (mains-last).
+- **F1 fuse + TC1 thermal cutoff in series with the element are mandatory.** The
+  comparator/latch is *control*, not *protection* — it can't save you from a
+  welded relay or a failed/detached sensor.
+- **Always-on rail = always-live internals.** True off is unplugging; the rocker
+  only stops heating.
+- Keep the meter/logic rail decoupled from heater switching transients, or the
+  needle twitches and the latch can glitch each cycle.
+
+---
+
+## 6. Open unknowns (measure before committing values)
+1. **М205 movement:** full-scale current and coil resistance — sets Re. Measure
+   first; guess wrong and the needle pins or barely moves.
+2. **Solenoid force/stroke** vs the chosen keyswitch (~0.5 N, ~2 mm): confirm
+   force *at* the working stroke (not headline force) and intermittent duty at
+   the fastest click rate (near boil).
+3. **LM35 low-end:** reads down to ~+2 °C with a GND pull-down; true 0 °C needs a
+   negative supply. Decide if that matters for the dial's bottom mark.
+4. **Sensor sealing/placement:** the LM35 must be waterproofed; element-mounted
+   (fast, overshoots) vs water-immersed (accurate, laggy) changes hysteresis feel.
+5. **VREF_PRECISE accuracy** now sets setpoint accuracy directly (no ratiometric
+   cancellation) — use a ≤0.5% reference and the master trim RT to null offset.
+```

kttl.sublime-project

@@ -2,10 +2,10 @@
 	"folders":
 	[
 		{
-			"path": "."
+			"path": ".",
 		},
 		{
 			"path": "/home/ntr/code/f411"
-		}
+		},
-	]
+	],
 }