diff --git a/src/main.cpp b/src/main.cpp index 2c8c0dcb8..86268ecac 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -764,12 +764,6 @@ void setup() screen->print("Started...\n"); -#ifdef SX126X_ANT_SW - // make analog PA vs not PA switch on SX126x eval board work properly - pinMode(SX126X_ANT_SW, OUTPUT); - digitalWrite(SX126X_ANT_SW, 1); -#endif - #ifdef PIN_PWR_DELAY_MS // This may be required to give the peripherals time to power up. delay(PIN_PWR_DELAY_MS); diff --git a/src/mesh/SX126xInterface.cpp b/src/mesh/SX126xInterface.cpp index fcb3e4edb..6d23206bd 100644 --- a/src/mesh/SX126xInterface.cpp +++ b/src/mesh/SX126xInterface.cpp @@ -25,9 +25,25 @@ SX126xInterface::SX126xInterface(LockingArduinoHal *hal, RADIOLIB_PIN_TYPE cs /// \return true if initialisation succeeded. template bool SX126xInterface::init() { -#ifdef SX126X_POWER_EN - pinMode(SX126X_POWER_EN, OUTPUT); + +// Typically, the RF switch on SX126x boards is controlled by two signals, which are negations of each other (switched RFIO +// paths). The negation is usually performed in hardware, or (suboptimal design) TXEN and RXEN are the two inputs to this style of +// RF switch. On some boards, there is no hardware negation between CTRL and ¬CTRL, but CTRL is internally connected to DIO2, and +// DIO2's switching is done by the SX126X itself, so the MCU can't control ¬CTRL at exactly the same time. One solution would be +// to set ¬CTRL as SX126X_TXEN or SX126X_RXEN, but they may already be used for another purpose, such as controlling another +// PA/LNA. Keeping ¬CTRL high seems to work, as long CTRL=1, ¬CTRL=1 has the opposite and stable RF path effect as CTRL=0 and +// ¬CTRL=1, this depends on the RF switch, but it seems this usually works. Better hardware design, which is done most the time, +// means this workaround is not necessary. +#ifdef SX126X_ANT_SW // Perhaps add RADIOLIB_NC check, and beforehand define as such if it is undefined, but it is not commonly + // used and not part of the 'default' set of pin definitions. + digitalWrite(SX126X_ANT_SW, HIGH); + pinMode(SX126X_ANT_SW, OUTPUT); +#endif + +#ifdef SX126X_POWER_EN // Perhaps add RADIOLIB_NC check, and beforehand define as such if it is undefined, but it is not commonly + // used and not part of the 'default' set of pin definitions. digitalWrite(SX126X_POWER_EN, HIGH); + pinMode(SX126X_POWER_EN, OUTPUT); #endif #if ARCH_PORTDUINO diff --git a/variants/rak11200/variant.h b/variants/rak11200/variant.h index 259fa6e87..01edb8b73 100644 --- a/variants/rak11200/variant.h +++ b/variants/rak11200/variant.h @@ -70,12 +70,12 @@ static const uint8_t SCK = 33; #define LORA_CS SS #define USE_SX1262 -#define SX126X_ANT_SW WB_IO2 +#define SX126X_ANT_SW WB_IO3 #define SX126X_CS SS // NSS for SX126X #define SX126X_DIO1 LORA_DIO1 #define SX126X_BUSY LORA_DIO2 #define SX126X_RESET LORA_RESET -#define SX126X_POWER_EN WB_IO3 +#define SX126X_POWER_EN WB_IO2 // DIO2 controlls an antenna switch and the TCXO voltage is controlled by DIO3 #define SX126X_DIO2_AS_RF_SWITCH #define SX126X_DIO3_TCXO_VOLTAGE 1.8