From 5c865367fda19ea7638ced2de405d14614dd4ba6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20NEDJAR?= <sebastien@nedjar.com>
Date: Fri, 13 Mar 2026 06:26:20 +0100
Subject: [PATCH 1/2] hts221: Auto-trigger one-shot conversion in power-down
 mode.

---
 lib/hts221/hts221/const.py  | 14 +++++++++++++
 lib/hts221/hts221/device.py | 41 ++++++++++++++++++++++++++++++++++++-
 2 files changed, 54 insertions(+), 1 deletion(-)

diff --git a/lib/hts221/hts221/const.py b/lib/hts221/hts221/const.py
index 8ea1e648..beb86fc8 100644
--- a/lib/hts221/hts221/const.py
+++ b/lib/hts221/hts221/const.py
@@ -27,3 +27,17 @@
 HTS221_T0_OUT_H = const(0x3D)
 HTS221_T1_OUT_L = const(0x3E)
 HTS221_T1_OUT_H = const(0x3F)
+
+# CTRL_REG1 bits
+HTS221_CTRL1_PD = const(0x80)
+HTS221_CTRL1_BDU = const(0x04)
+HTS221_CTRL1_ODR_MASK = const(0x03)
+
+# CTRL_REG2 bits
+HTS221_CTRL2_BOOT = const(0x80)
+HTS221_CTRL2_HEATER = const(0x02)
+HTS221_CTRL2_ONE_SHOT = const(0x01)
+
+# STATUS_REG bits
+HTS221_STATUS_H_DA = const(0x02)
+HTS221_STATUS_T_DA = const(0x01)
diff --git a/lib/hts221/hts221/device.py b/lib/hts221/hts221/device.py
index fdacc307..0c40ef69 100644
--- a/lib/hts221/hts221/device.py
+++ b/lib/hts221/hts221/device.py
@@ -1,4 +1,5 @@
 from machine import I2C
+from time import sleep_ms
 
 from hts221.const import *
 
@@ -84,8 +85,32 @@ def getAv(self):
     def setAv(self, av=0):
         self._write_reg(HTS221_AV_CONF, av)
 
+    # one-shot / auto-trigger helpers
+    def _is_power_down(self):
+        return (self._read_reg(HTS221_CTRL_REG1) & HTS221_CTRL1_PD) == 0
+
+    def _is_one_shot_mode(self):
+        ctrl1 = self._read_reg(HTS221_CTRL_REG1)
+        is_active = bool(ctrl1 & HTS221_CTRL1_PD)
+        odr = ctrl1 & HTS221_CTRL1_ODR_MASK
+        return is_active and odr == 0
+
+    def trigger_one_shot(self):
+        ctrl1 = self._read_reg(HTS221_CTRL_REG1)
+        ctrl1 |= HTS221_CTRL1_PD | HTS221_CTRL1_BDU
+        ctrl1 &= ~HTS221_CTRL1_ODR_MASK
+        self._write_reg(HTS221_CTRL_REG1, ctrl1)
+        ctrl2 = self._read_reg(HTS221_CTRL_REG2)
+        self._write_reg(HTS221_CTRL_REG2, ctrl2 | HTS221_CTRL2_ONE_SHOT)
+        sleep_ms(15)
+
+    def _ensure_data(self):
+        if self._is_power_down() or self._is_one_shot_mode():
+            self.trigger_one_shot()
+
     # calculate Temperature
     def temperature(self):
+        self._ensure_data()
         t = self._read_reg16(HTS221_TEMP_OUT_L)
         return self.T0_degC + (self.T1_degC - self.T0_degC) * (t - self.T0_OUT) / (
             self.T1_OUT - self.T0_OUT
@@ -93,11 +118,25 @@ def temperature(self):
 
     # calculate Humidity
     def humidity(self):
+        self._ensure_data()
         t = self._read_reg16(HTS221_HUMIDITY_OUT_L)
         return self.H0_rH + (self.H1_rH - self.H0_rH) * (t - self.H0_OUT) / (
             self.H1_OUT - self.H0_OUT
         )
 
     # get Humidity and Temperature
+    def read(self):
+        self._ensure_data()
+        h = self._read_reg16(HTS221_HUMIDITY_OUT_L)
+        t = self._read_reg16(HTS221_TEMP_OUT_L)
+        humidity = self.H0_rH + (self.H1_rH - self.H0_rH) * (h - self.H0_OUT) / (
+            self.H1_OUT - self.H0_OUT
+        )
+        temperature = self.T0_degC + (self.T1_degC - self.T0_degC) * (t - self.T0_OUT) / (
+            self.T1_OUT - self.T0_OUT
+        )
+        return humidity, temperature
+
     def get(self):
-        return [self.humidity(), self.temperature()]
+        h, t = self.read()
+        return [h, t]

From 54b9e0c662bc915d5e59af56fd6468580b1c5193 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20NEDJAR?= <sebastien@nedjar.com>
Date: Fri, 13 Mar 2026 13:36:55 +0100
Subject: [PATCH 2/2] hts221: Add hardware test for auto-trigger after
 poweroff.

---
 tests/scenarios/hts221.yaml | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/tests/scenarios/hts221.yaml b/tests/scenarios/hts221.yaml
index c0adacde..dbfcfd62 100644
--- a/tests/scenarios/hts221.yaml
+++ b/tests/scenarios/hts221.yaml
@@ -85,6 +85,19 @@ tests:
     expect_not_none: true
     mode: [mock, hardware]
 
+  - name: "Auto-trigger after poweroff"
+    action: hardware_script
+    script: |
+      from machine import I2C
+      from hts221.device import HTS221
+      i2c = I2C(1)
+      sensor = HTS221(i2c)
+      sensor.poweroff()
+      t = sensor.temperature()
+      result = 10.0 <= t <= 45.0
+    expect_true: true
+    mode: [hardware]
+
   - name: "Temperature feels correct"
     action: manual
     display: