diff --git a/variants/rak3401/RAK3401Board.cpp b/variants/rak3401/RAK3401Board.cpp index b9431c929..4c18c6dde 100644 --- a/variants/rak3401/RAK3401Board.cpp +++ b/variants/rak3401/RAK3401Board.cpp @@ -23,10 +23,36 @@ void RAK3401Board::begin() { pinMode(PIN_3V3_EN, OUTPUT); digitalWrite(PIN_3V3_EN, HIGH); -#ifdef P_LORA_PA_EN - // Initialize RAK13302 1W LoRa transceiver module PA control pin + // 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); // Start with PA disabled - delay(10); // Allow PA module to initialize + 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 + + pinMode(SX126X_POWER_EN, OUTPUT); + digitalWrite(SX126X_POWER_EN, HIGH); // CPS=1: enable TX/RX paths + + delay(1); // SKY66122 turn-on settling time +} + +#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 3V3 switched peripherals + digitalWrite(PIN_3V3_EN, LOW); + + enterSystemOff(reason); +} #endif -} \ No newline at end of file diff --git a/variants/rak3401/RAK3401Board.h b/variants/rak3401/RAK3401Board.h index 20edf9069..8ca5b52eb 100644 --- a/variants/rak3401/RAK3401Board.h +++ b/variants/rak3401/RAK3401Board.h @@ -38,13 +38,14 @@ class RAK3401Board : public NRF52BoardDCDC { return "RAK 3401"; } -#ifdef P_LORA_PA_EN + // 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); // Enable PA before transmission + digitalWrite(P_LORA_PA_EN, HIGH); // CTX=1: TX mode, boost on } void onAfterTransmit() override { - digitalWrite(P_LORA_PA_EN, LOW); // Disable PA after transmission to save power + digitalWrite(P_LORA_PA_EN, LOW); // CTX=0: RX mode, boost off } -#endif }; diff --git a/variants/rak3401/platformio.ini b/variants/rak3401/platformio.ini index 7467ceb9c..ecea03171 100644 --- a/variants/rak3401/platformio.ini +++ b/variants/rak3401/platformio.ini @@ -11,6 +11,7 @@ build_flags = ${nrf52_base.build_flags} -D LORA_TX_POWER=22 -D SX126X_CURRENT_LIMIT=140 -D SX126X_RX_BOOSTED_GAIN=1 + -D SX126X_REGISTER_PATCH=1 ; Patch register 0x8B5 for improved RX with SKY66122 FEM build_src_filter = ${nrf52_base.build_src_filter} +<../variants/rak3401> + diff --git a/variants/rak3401/variant.h b/variants/rak3401/variant.h index 56fe08169..f2ef4ace8 100644 --- a/variants/rak3401/variant.h +++ b/variants/rak3401/variant.h @@ -147,8 +147,14 @@ static const uint8_t AREF = PIN_AREF; #define SX126X_BUSY (9) #define SX126X_RESET (4) -#define SX126X_POWER_EN (21) -// DIO2 controlls an antenna switch and the TCXO voltage is controlled by DIO3 +// 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 + +// DIO2 has a NC 0R footprint (R25) to CTX; not connected by default #define SX126X_DIO2_AS_RF_SWITCH #define SX126X_DIO3_TCXO_VOLTAGE 1.8 @@ -159,7 +165,6 @@ static const uint8_t AREF = PIN_AREF; #define P_LORA_DIO_1 SX126X_DIO1 #define P_LORA_BUSY SX126X_BUSY #define P_LORA_RESET SX126X_RESET -#define P_LORA_PA_EN 31 // enables 3.3V periphery like GPS or IO Module // Do not toggle this for GPS power savings