Espressif ESP01 Quick Start Manual page 11

4 . PERIPHERALS AND SENSORS
Interface
Motor PWM
LED PWM
UART
I2C
Signal
PWM0_OUT0 ~ 2
PWM1_OUT_IN0 ~ 2
PWM0_FLT_IN0 ~ 2
PWM1_FLT_IN0 ~ 2
PWM0_CAP_IN0 ~ 2
PWM1_CAP_IN0 ~ 2
PWM0_SYNC_IN0 ~ 2
PWM1_SYNC_IN0 ~ 2
ledc_hs_sig_out0 ~ 7
ledc_ls_sig_out0 ~ 7
U0RXD_in
U0CTS_in
U0DSR_in
U0TXD_out
U0RTS_out
U0DTR_out
U1RXD_in
U1CTS_in
U1TXD_out
U1RTS_out
U2RXD_in
U2CTS_in
U2TXD_out
U2RTS_out
I2CEXT0_SCL_in
I2CEXT0_SDA_in
I2CEXT1_SCL_in
I2CEXT1_SDA_in
I2CEXT0_SCL_out
I2CEXT0_SDA_out
I2CEXT1_SCL_out
I2CEXT1_SDA_out
Pin Function
Three channels of 16-bit timers generate
PWM waveforms. Each channel has a pair
Any GPIOs* of output signals, three fault detection
signals, three event-capture signals, and
three sync signals.
16 independent channels @80 MHz
Any GPIOs*
clock/RTC CLK. Duty accuracy: 16 bits.
Two UART devices with hardware
Any GPIOs*
flow-control and DMA
Any GPIOs* Two I2C devices in slave or master modes