setup fliplink

This commit is contained in:
Nathan Rashleigh committed 2026-06-28 15:46:42 +10:00
1 parent 6a0e3f0070
commit 5bb0cde777
6 files changed
+269 -4

No files matched your search

+4
View File
@@ -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",
+1 -1
View File
@@ -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"
View File
Whitespace-only changes.
+59
View File
@@ -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
+202
View File
@@ -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.
```
+3 -3
View File
@@ -2,10 +2,10 @@
"folders":
[
{
"path": "."
"path": ".",
},
{
"path": "/home/ntr/code/f411"
}
]
},
],
}