diff --git a/variants/rak3401/RAK3401Board.cpp b/variants/rak3401/RAK3401Board.cpp index 4c18c6dd..33e1de42 100644 --- a/variants/rak3401/RAK3401Board.cpp +++ b/variants/rak3401/RAK3401Board.cpp @@ -20,37 +20,27 @@ void RAK3401Board::begin() { Wire.begin(); + // PIN_3V3_EN (WB_IO2, P0.34) controls the 3V3_S switched peripheral rail + // AND the 5V boost regulator (U5) on the RAK13302 that powers the SKY66122 PA. + // Must stay HIGH during radio operation — do not toggle for power saving. pinMode(PIN_3V3_EN, OUTPUT); digitalWrite(PIN_3V3_EN, HIGH); - // Initialize SKY66122-11 FEM on the RAK13302 module. - // CSD (P0.24) and CPS (P0.21) must be HIGH for both TX and RX modes. - // CTX (P0.31) selects TX(HIGH) vs RX(LOW) and also enables the 5V boost - // converter that powers the PA section (VCC1/VCC2). - // The LNA section (VSUP1/VCC0) runs on 3.3V and works with boost off. - // - // Drive CTX LOW first to prevent transient TX mode (Mode 2) while CSD/CPS - // are being enabled — the RAK13302 has no pull-downs on these pins. - pinMode(P_LORA_PA_EN, OUTPUT); - digitalWrite(P_LORA_PA_EN, LOW); // CTX=0: RX mode, boost off - - pinMode(P_LORA_PA_CSD, OUTPUT); - digitalWrite(P_LORA_PA_CSD, HIGH); // CSD=1: enable FEM - + // Enable SKY66122-11 FEM on the RAK13302 module. + // CSD and CPS are tied together on the RAK13302 PCB, routed to IO3 (P0.21). + // HIGH = FEM active (LNA for RX, PA path available for TX). + // TX/RX switching (CTX) is handled by SX1262 DIO2 via SetDIO2AsRfSwitchCtrl. pinMode(SX126X_POWER_EN, OUTPUT); - digitalWrite(SX126X_POWER_EN, HIGH); // CPS=1: enable TX/RX paths - - delay(1); // SKY66122 turn-on settling time + digitalWrite(SX126X_POWER_EN, HIGH); + delay(1); // SKY66122 turn-on settling time (tON = 3us typ) } #ifdef NRF52_POWER_MANAGEMENT void RAK3401Board::initiateShutdown(uint8_t reason) { - // Put SKY66122 in guaranteed <1 uA shutdown (Mode 4: CSD=0, CTX=0, CPS=0) - digitalWrite(P_LORA_PA_EN, LOW); // CTX=0, boost off - digitalWrite(SX126X_POWER_EN, LOW); // CPS=0 - digitalWrite(P_LORA_PA_CSD, LOW); // CSD=0 + // Disable SKY66122 FEM (CSD+CPS LOW = shutdown, <1 uA) + digitalWrite(SX126X_POWER_EN, LOW); - // Disable 3V3 switched peripherals + // Disable 3V3 switched peripherals and 5V boost digitalWrite(PIN_3V3_EN, LOW); enterSystemOff(reason); diff --git a/variants/rak3401/RAK3401Board.h b/variants/rak3401/RAK3401Board.h index 8ca5b52e..3a080d5e 100644 --- a/variants/rak3401/RAK3401Board.h +++ b/variants/rak3401/RAK3401Board.h @@ -38,14 +38,6 @@ public: return "RAK 3401"; } - // SKY66122 FEM TX/RX switching via CTX pin. - // CTX=HIGH: TX mode + 5V boost ON (PA powered from VCC1/VCC2) - // CTX=LOW: RX mode + 5V boost OFF (LNA powered from VSUP1 at 3.3V) - void onBeforeTransmit() override { - digitalWrite(P_LORA_PA_EN, HIGH); // CTX=1: TX mode, boost on - } - - void onAfterTransmit() override { - digitalWrite(P_LORA_PA_EN, LOW); // CTX=0: RX mode, boost off - } + // TX/RX switching is handled by SX1262 DIO2 -> SKY66122 CTX (hardware-timed). + // No onBeforeTransmit/onAfterTransmit overrides needed. }; diff --git a/variants/rak3401/variant.h b/variants/rak3401/variant.h index f2ef4ace..268aec53 100644 --- a/variants/rak3401/variant.h +++ b/variants/rak3401/variant.h @@ -147,14 +147,15 @@ static const uint8_t AREF = PIN_AREF; #define SX126X_BUSY (9) #define SX126X_RESET (4) -// SKY66122-11 FEM control pins (active HIGH, active LOW = shutdown <1uA) -// CSD+CPS must be HIGH for TX and RX; CTX selects TX(HIGH) vs RX(LOW) -// CTX also enables the 5V boost converter for the PA during TX -#define P_LORA_PA_CSD (24) // P0.24 -> SKY66122 CSD (pin 11) - FEM enable -#define SX126X_POWER_EN (21) // P0.21 -> SKY66122 CPS (pin 1) - path select -#define P_LORA_PA_EN (31) // P0.31 -> SKY66122 CTX (pin 2) - TX/RX + boost EN +// SKY66122-11 FEM control on the RAK13302 module: +// CSD + CPS are tied together on the PCB, routed to WisBlock IO3 (P0.21). +// Setting IO3 HIGH enables the FEM (LNA for RX, PA path for TX). +// CTX is connected to SX1262 DIO2 — the radio handles TX/RX switching +// in hardware via SetDIO2AsRfSwitchCtrl (microsecond-accurate, no GPIO needed). +// The 5V boost for the PA is enabled by WB_IO2 (P0.34 = PIN_3V3_EN). +#define SX126X_POWER_EN (21) // P0.21 = IO3 -> SKY66122 CSD+CPS (FEM enable) -// DIO2 has a NC 0R footprint (R25) to CTX; not connected by default +// CTX is driven by SX1262 DIO2, not a GPIO #define SX126X_DIO2_AS_RF_SWITCH #define SX126X_DIO3_TCXO_VOLTAGE 1.8