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ESP32 I2C: decide TwoWire::end() in one place; recover a controller left bus busy #368

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Merged
lovyan03 merged 2 commits into from
Oct 20, 2026
Merged

ESP32 I2C: decide TwoWire::end() in one place; recover a controller left bus busy #368

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a0f30f2
ESP32 I2C: decide TwoWire::end() in one place, also without core_vers…
ainyan03 Oct 20, 2026
cacd7f5
ESP32 I2C: recover a controller left bus busy before a transfer
ainyan03 Oct 20, 2026
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76 changes: 32 additions & 44 deletions src/lgfx/v1/platforms/esp32/common.inl
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Original file line number Diff line number Diff line change
Expand Up @@ -1240,6 +1240,23 @@ namespace lgfx
#include <core_version.h>
#endif

// TwoWire::end() exists from core 2.0.1 (0x44c11981 is 2.0.0). Some board packages lack
// core_version.h; they are judged by esp_arduino_version.h, which 2.0.1 and 2.0.2 still
// report as 2.0.0, hence the git version first.
#if defined ( ARDUINO ) && __has_include (<Wire.h>) && defined ( ESP_IDF_VERSION_VAL )
#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(4, 0, 0)
#if defined ( ARDUINO_ESP32_GIT_VER )
#if ARDUINO_ESP32_GIT_VER != 0x44c11981
#define LGFX_TWOWIRE_HAS_END
#endif
#elif defined ( ESP_ARDUINO_VERSION_VAL )
#if ESP_ARDUINO_VERSION >= ESP_ARDUINO_VERSION_VAL(2, 0, 1)
#define LGFX_TWOWIRE_HAS_END
#endif
#endif
#endif
#endif

// Register layout of the I2C block. Only the older chips are named; anything not
// listed is taken to carry the current layout, so a new target lands there rather
// than on the ESP32 one.
Expand Down Expand Up @@ -1591,35 +1608,6 @@ namespace lgfx
updateDev(dev);
}

void setPins(i2c_dev_t* dev, gpio_num_t scl, gpio_num_t sda)
{
pin_sda = sda;
pin_scl = scl;
#if defined ( ARDUINO ) && __has_include (<Wire.h>)
#if defined ( ESP_IDF_VERSION_VAL )
#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(4, 0, 0)
#if defined ARDUINO_ESP32_GIT_VER
#if ARDUINO_ESP32_GIT_VER != 0x44c11981
#define USE_TWOWIRE_SETPINS
#endif
#endif
#endif
#endif

#if LGFX_HP_I2C_NUM == 1
auto twowire = &Wire;
#else
auto twowire = ((dev == &I2C0) ? &Wire : &Wire1);
#endif

#if defined ( USE_TWOWIRE_SETPINS )
twowire->setPins(sda, scl);
#else
twowire->begin((int)sda, (int)scl);
#endif
#endif
}

// A low power port is opened through the ESP-IDF driver even in an Arduino build, where
// the normal ports go through TwoWire, so the handle is needed in both cases.
#if __has_include(<driver/i2c_master.h>) \
Expand Down Expand Up @@ -1979,17 +1967,13 @@ namespace lgfx
#endif
{
#if defined ( ARDUINO ) && __has_include (<Wire.h>) && defined ( ESP_IDF_VERSION_VAL )
#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(4, 0, 0)
#if defined ARDUINO_ESP32_GIT_VER
#if ARDUINO_ESP32_GIT_VER != 0x44c11981
#if LGFX_HP_I2C_NUM == 1
#if defined ( LGFX_TWOWIRE_HAS_END )
#if LGFX_HP_I2C_NUM == 1
auto twowire = &Wire;
#else
#else
auto twowire = ((i2c_port == 0) ? &Wire : &Wire1);
#endif
twowire->end();
#endif
#endif
twowire->end();
#endif
#elif __has_include(<driver/i2c_master.h>)
auto bus_handle = i2c_context[i2c_port].i2c_bus_handle;
Expand Down Expand Up @@ -2404,6 +2388,16 @@ namespace lgfx
}
i2c_context[i2c_port].save_reg(dev);

// Still busy although no transfer of ours is running: a slave glitch can leave the
// controller waiting for a STOP forever (ESP32 has no FSM reset bit). Recover the bus
// and the controller as the ESP-IDF driver does before it starts a command (the C2 and
// C3 skip the peripheral reset there and rely on fsm_rst below).
if (getBusBusy(dev))
{
ESP_LOGV("LGFX", "i2c::beginTransaction : bus busy, recover");
i2c_stop(i2c_port);
}

// A low power port reaches its pads through the low power IO domain, which set_pin()
// knows nothing about: routing them through the normal GPIO matrix here would
// disconnect the port from its own pins on every transaction. A shared port keeps
Expand Down Expand Up @@ -2746,18 +2740,12 @@ namespace lgfx
#if defined ( ARDUINO ) && __has_include (<Wire.h>)
_twowire = nullptr;
if (search_sda >=0 && search_scl >= 0) {
#if defined ( ARDUINO ) && __has_include (<Wire.h>) && defined ( ESP_IDF_VERSION_VAL )
#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(4, 0, 0)
#if defined ARDUINO_ESP32_GIT_VER
#if ARDUINO_ESP32_GIT_VER != 0x44c11981
#if defined ( LGFX_TWOWIRE_HAS_END )
_twowire = &Wire;
#if defined (I2CEXT1_SDA_IN_IDX)
if (i2c_port != 0) { _twowire = &Wire1; }
#endif
_twowire->end();
#endif
#endif
#endif
#endif
}
#endif
Expand Down
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