From b8e95fbb87ecf0bf85d3b723c8a592638604a9e8 Mon Sep 17 00:00:00 2001
From: Ayke van Laethem <aykevanlaethem@gmail.com>
Date: Fri, 28 Nov 2025 10:32:46 +0100
Subject: [PATCH] scd4x: add support for SCD41 single-shot measurements

I have a SCD41, and would like to use it for single shot measurements
instead of "low power periodic" measurements to achieve much lower
average current consumption.
---
 scd4x/registers.go | 1 +
 scd4x/scd4x.go     | 7 +++++++
 2 files changed, 8 insertions(+)

diff --git a/scd4x/registers.go b/scd4x/registers.go
index af057b428..fb258640a 100644
--- a/scd4x/registers.go
+++ b/scd4x/registers.go
@@ -22,4 +22,5 @@ const (
 	CmdStartLowPowerPeriodicMeasurement = 0x21AC
 	CmdStartPeriodicMeasurement         = 0x21B1
 	CmdStopPeriodicMeasurement          = 0x3F86
+	CmdMeasureSingleShot                = 0x219D
 )
diff --git a/scd4x/scd4x.go b/scd4x/scd4x.go
index e605254d3..62e97d745 100644
--- a/scd4x/scd4x.go
+++ b/scd4x/scd4x.go
@@ -82,6 +82,13 @@ func (d *Device) StartLowPowerPeriodicMeasurement() error {
 	return d.sendCommand(CmdStartLowPowerPeriodicMeasurement)
 }
 
+// MeasureSingleShot starts a single measurement cycle (SCD41 only). After this
+// command is complete, the caller should wait for 5000ms before trying to read
+// the result.
+func (d *Device) MeasureSingleShot() error {
+	return d.sendCommand(CmdMeasureSingleShot)
+}
+
 // ReadData reads the data from the sensor and caches it.
 func (d *Device) ReadData() error {
 	if err := d.sendCommandWithResult(CmdReadMeasurement, d.rx[0:9]); err != nil {