From 4223a3e8bbb146399c13bb305e92c95451deba00 Mon Sep 17 00:00:00 2001
From: Thomas Abbott <thomas@reversebiased.com>
Date: Fri, 30 Jan 2026 12:30:35 -0800
Subject: [PATCH 1/2] power saving: enable DCDC, reduce clock speeds and
 voltage

---
 variants/rpi_picow/PicoWBoard.cpp | 60 +++++++++++++++++++++++++++++++
 variants/rpi_picow/PicoWBoard.h   | 12 +++++++
 variants/rpi_picow/platformio.ini |  1 +
 3 files changed, 73 insertions(+)

diff --git a/variants/rpi_picow/PicoWBoard.cpp b/variants/rpi_picow/PicoWBoard.cpp
index f345f96df..d58875281 100644
--- a/variants/rpi_picow/PicoWBoard.cpp
+++ b/variants/rpi_picow/PicoWBoard.cpp
@@ -19,6 +19,66 @@ static void disconnect_callback(uint16_t conn_handle, uint8_t reason) {
 }
 
 void PicoWBoard::begin() {
+  // 1. Force SMPS to PFM (Power Save) Mode
+  pinMode(PIN_SMPS_MODE, OUTPUT);
+  digitalWrite(PIN_SMPS_MODE, LOW);
+
+  // 2. Detect Power Source
+  pinMode(PIN_VBUS_DET, INPUT);
+  bool usb_connected = digitalRead(PIN_VBUS_DET);
+
+  if (usb_connected) {
+    // --- USB MODE (Performance) ---
+    // Must run at 48MHz+ for USB to work
+    set_sys_clock_khz(48000, true); 
+    
+    // Ensure USB Clock is enabled
+    clock_configure(clk_usb,
+                    0,
+                    CLOCKS_CLK_USB_CTRL_AUXSRC_VALUE_CLKSRC_PLL_USB,
+                    48 * MHZ,
+                    48 * MHZ);
+    
+    // Ensure ADC runs from USB PLL (Standard 48MHz)
+    clock_configure(clk_adc,
+                    0,
+                    CLOCKS_CLK_ADC_CTRL_AUXSRC_VALUE_CLKSRC_PLL_USB,
+                    48 * MHZ,
+                    48 * MHZ);
+
+  } else {
+    // --- BATTERY MODE (Deep Power Saving) ---
+    
+    // A. Move ADC to System Clock BEFORE killing USB PLL
+    // This keeps the ADC alive, even though USB PLL is about to die.
+    // It will run at 18MHz (Slower, but fine for battery reading).
+    clock_configure(clk_adc,
+                    0,
+                    CLOCKS_CLK_ADC_CTRL_AUXSRC_VALUE_CLKSRC_PLL_SYS,
+                    18 * MHZ,
+                    18 * MHZ);
+
+    // B. Drop System Clock to 18 MHz
+    set_sys_clock_khz(18000, true); 
+    
+    // C. Disable USB Clock & PLL
+    // The USB PLL consumes ~2-3mA. We turn it off it here.
+    clock_stop(clk_usb);
+    pll_deinit(pll_usb);
+    
+    // D. Lower Core Voltage to 0.95V
+    vreg_set_voltage(VREG_VOLTAGE_0_95);
+  }
+
+  // 3. Reconfigure Peripheral Clock to match System Clock
+  // This ensures UART/SPI timings stay correct at the new 18MHz speed
+  clock_configure(clk_peri,
+                  0,
+                  CLOCKS_CLK_ADC_CTRL_AUXSRC_VALUE_CLKSRC_PLL_SYS, // Run peripherals from Sys Clock
+                  usb_connected ? 48000 * 1000 : 18000 * 1000,
+                  usb_connected ? 48000 * 1000 : 18000 * 1000);
+
+
   // for future use, sub-classes SHOULD call this from their begin()
   startup_reason = BD_STARTUP_NORMAL;
   pinMode(PIN_VBAT_READ, INPUT);
diff --git a/variants/rpi_picow/PicoWBoard.h b/variants/rpi_picow/PicoWBoard.h
index 708e96558..c58b5ce99 100644
--- a/variants/rpi_picow/PicoWBoard.h
+++ b/variants/rpi_picow/PicoWBoard.h
@@ -3,6 +3,18 @@
 #include <MeshCore.h>
 #include <Arduino.h>
 
+// RP2040 Specific Includes for Clock/Power
+#include "pico/stdlib.h"
+#include "hardware/vreg.h"
+#include "hardware/clocks.h"
+#include "hardware/pll.h"
+#include "hardware/structs/pll.h"
+#include "hardware/structs/clocks.h"
+
+// Pico Standard Pins
+#define PIN_SMPS_MODE 23
+#define PIN_VBUS_DET  24
+
 // built-ins
 #define  PIN_VBAT_READ    26
 #define  ADC_MULTIPLIER   (3.1 * 3.3 * 1000) // MT Uses 3.1
diff --git a/variants/rpi_picow/platformio.ini b/variants/rpi_picow/platformio.ini
index ec5cdb839..9f0843777 100644
--- a/variants/rpi_picow/platformio.ini
+++ b/variants/rpi_picow/platformio.ini
@@ -17,6 +17,7 @@ build_flags = ${rp2040_base.build_flags}
   -D P_LORA_MOSI=11
   -D SX126X_DIO2_AS_RF_SWITCH=true
   -D SX126X_DIO3_TCXO_VOLTAGE=1.8
+  -D SX126X_REGULATOR=RADIOLIB_SX126X_REGULATOR_DCDC
   -D SX126X_CURRENT_LIMIT=130
   -D SX126X_RX_BOOSTED_GAIN=1
   -D LORA_TX_POWER=22

From b3b118e01d1b6a358eef9ca992ee86cbb7c5c2da Mon Sep 17 00:00:00 2001
From: Thomas Abbott <github@reversebiased.com>
Date: Fri, 30 Jan 2026 15:47:29 -0800
Subject: [PATCH 2/2] Remove unused SX1262 regulator definition from
 platformio.ini

Removed the DCDC regulator definition for SX1262. It's not used, not passed to Radiolib. DCDC is the default.
---
 variants/rpi_picow/platformio.ini | 1 -
 1 file changed, 1 deletion(-)

diff --git a/variants/rpi_picow/platformio.ini b/variants/rpi_picow/platformio.ini
index 9f0843777..ec5cdb839 100644
--- a/variants/rpi_picow/platformio.ini
+++ b/variants/rpi_picow/platformio.ini
@@ -17,7 +17,6 @@ build_flags = ${rp2040_base.build_flags}
   -D P_LORA_MOSI=11
   -D SX126X_DIO2_AS_RF_SWITCH=true
   -D SX126X_DIO3_TCXO_VOLTAGE=1.8
-  -D SX126X_REGULATOR=RADIOLIB_SX126X_REGULATOR_DCDC
   -D SX126X_CURRENT_LIMIT=130
   -D SX126X_RX_BOOSTED_GAIN=1
   -D LORA_TX_POWER=22