doc

README.md

@@ -20,5 +20,54 @@ _Bare metal ESP32-C3 DevBoard_
 - Rich connectivity for IoT applications: Wi-Fi and Bluetooth 5 (LE) with long-range support
 - Bluetooth LE SIG Mesh and Wi-FI Mesh support
 - 22 GPIOs
+- 
+### General Purpose GPIOs
+
+_The table below reconciles wiring of ESP32 module GPIOs with board pins._
+
+| GPIO | Physical Pin | Type | Description |
+| --- | --- | --- | --- |
+| EN | 1 | I | Enable/Disable the chip (active HIGH). |
+| IO4 | 2 | I/O/T | GPIO4, __ADC1_CH4__, FSPIHD, MTMS  |
+| IO5 | 3 | I/O/T | GPIO5, __ADC2_CH0__, FSPIWP, MTDI |
+| IO6 | 4 | I/O/T | GPIO6, FSPICLK, MTCK |
+| IO8 | 5 | I/O/T | GPIO8, __SDA__ |
+| IO7 | 6 | I/O/T | GPIO7, FSPDI, MTDO |
+| IO10 | 7 | I/O/T | GPIO10, FSPICS0 |
+| IO9 | 8 | I/O/T | GPIO9, __SCL__ |
+| USB_D+ | 9 | I/O/T | GOIO19, __USB D+__ |
+| RxD | 10 |  I/O/T | GPIO20, __U0RxD__ |
+| USB_D- | 11 |  I/O/T | GPIO18, __USB D-__ |
+| TxD | 12 |  I/O/T | GPIO21, __U0TxD__ |
+| IO3 | 13 | I/O/T | GPIO3, __ADC1_CH3__ |
+| IO2 | 14 |  I/O/T | GPIO2, __ADC1_CH2__, FSPIQ |
+| IO1 | 15 |  I/O/T | GPIO1, __ADC1_CH1__, XTAL_32K_N |
+| IO0 | 16 |  I/O/T | GPIO0, __ADC1_CH0__, XTAL_32K_P |
+
+### ESP32-C3 Current Consumption Characteristics
+
+|  Mode  |  Peak (mA)  |
+|  ---  |  ---:  |
+| RF working |  345mA  |
+| Modem sleep[ the CPU is powered on @ 160 MHz |  20mA  |
+| Light sleep |  130 uA  |
+| Deep sleep; RTC timer + RTC memory |  5 uA  |
+| Power off |  1 uA  |
+
+### Reserved GPIOs
+
+_The table below lists strapping and reserved pins._
+
+ESP32-C3 has three strapping pins: GPIO2, GPIO8 and GPIO9. By default, GPIO9 is connected to the internal pull-up resistor. If GPIO9 is not connected or connected to an external high-impedance circuit, the latched bit value will be '1'.
+
+During the chip's system reset, the latches of strapping pins samle re voltage level as strapping bits of '0' or '1', and hold these bits until the chip is powered down. After reset, the strapping pins work as normal-function pins.
+
+| GPIO | Physical Pin | Adapter Pin | Description |
+| --- | --- | --- | --- |
+| EN | 1 | 2 | ESP32-C3 Enable pin |
+| IO9 | 8 | 8 | Strapping pin |
+| IO8 | 5 | 7 | Strapping pin |
+| IO18 | 11 | 13 | USB D- |
+| IO19 | 9 | 14 | USB D+ |
 
 # Schematic