> For the complete documentation index, see [llms.txt](https://libooogo.gitbook.io/esplane/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://libooogo.gitbook.io/esplane/esp32-development-notes/esp32-yin-jiao-zi-yuan-fen-pei-yu-shi-yong-jian-yi.md).

# ESP32 Pin Resource Allocation And Usage Recommendations

\# ESP32引脚资源分配与使用建议

## 一、ESP32-D2WD芯片

### 1. ESP32-D2WD特殊引脚查询表&注意事项

| 引脚名                   | 芯片No. | 电源          | 是否建议使用 | 原因                                                                              |
| --------------------- | ----- | ----------- | ------ | ------------------------------------------------------------------------------- |
| GPIO0                 | 23    | VDD3P3\_RTC | 不优先    | Strapping Pins\*  用于切换Booting Mode 复位完成后可以正常使用                                  |
| GPIO2                 | 22    | VDD3P3\_RTC | 不优先    | Strapping Pins\* 用于切换Booting Mode 复位完成后可以正常使用                                   |
| GPIO5                 | 34    | VDD3P3\_CPU | 不优先    | Strapping Pins\* 与MTDO 用于切换Timing of SDIO Slave                                 |
| GPIO12 /MTDI          | 18    | VDD3P3\_RTC | 不优先    | Strapping Pins\* 用于确认flash工作电压 1:1.8v  0:3.3v(default)                          |
| GPIO15 /MTDO          | 21    | VDD3P3\_RTC | 不优先    | Strapping Pins\* 时钟相关                                                           |
| GPIO16\*              | 25    | VDD\_SDIO   | 不建议    | 需查阅模组原理图  GPIO16 和 GPIO17  SD\_CMD, SD\_CLK, SD\_DATA\_0  SD\_DATA\_1 用于外接flash |
| GPIO17\*              | 27    | VDD\_SDIO   | 不建议    | 需查阅模组原理图  同上 (该引脚电压与flash供电电压一致)                                                |
| GPIO 34 /VDET\_1      | 10    | VDD3P3\_RTC | 不建议    | 只能作为输入引脚                                                                        |
| GPIO 35 /VDET\_2      | 11    | VDD3P3\_RTC | 不建议    | 只能作为输入引脚                                                                        |
| GPIO 36 /SENSOR\_VP   | 5     | VDD3P3\_RTC | 不建议    | 只能作为输入引脚                                                                        |
| GPIO 37 /SENSOR\_CAPP | 6     | VDD3P3\_RTC | 不建议    | 只能作为输入引脚                                                                        |
| GPIO 38 /SENSOR\_CAPN | 7     | VDD3P3\_RTC | 不建议    | 只能作为输入引脚                                                                        |
| GPIO 39 /SENSOR\_VN   | 8     | VDD3P3\_RTC | 不建议    | 只能作为输入引脚                                                                        |

> 1. ESP32 has five strapping pins: • MTDI • GPIO0 • GPIO2 • MTDO • GPIO5
> 2. 注意GPIO16、GPIO17在ESP32-WROOM-32D模组中并没有用于连接flash,且该模组flash为3.3v,所以能够在没有其他IO资源的情况下使用.`In most cases, the data port connection between the ESP32 and external flash is as follows: SD_DATA0/SPIQ =IO1/DO, SD_DATA1/SPID = IO0/DI, SD_DATA2/SPIHD = IO3/HOLD#, SD_DATA3/SPIWP = IO2/WP#.`

### 2. ESP32-D2WD芯片封装

![ESP32-D0WD两种封装](https://img-blog.csdnimg.cn/20191120151226822.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzIwNTE1NDYx,size_16,color_FFFFFF,t_70)

### 3. ESP32-D2WD芯片引脚定义

| Name         | No. | Type | Function                                                                                 |   |                       |
| ------------ | --- | ---- | ---------------------------------------------------------------------------------------- | - | --------------------- |
| -            | -   | -    | **Analog**                                                                               |   |                       |
| VDDA         | 1   | P    | Analog power supply (2.3V – 3.6V)                                                        |   |                       |
| LNA\_IN      | 2   | I/O  | RF input and output                                                                      |   |                       |
| VDD3P3       | 3   | P    | Analog power supply (2.3V – 3.6V)                                                        |   |                       |
| VDD3P3       | 4   | P    | Analog power supply (2.3V – 3.6V)                                                        |   |                       |
| -            | -   | -    | **VDD3P3\_RTC**                                                                          |   |                       |
| SENSOR\_VP   | 5   | I    | GPIO36, ADC1\_CH0, RTC\_GPIO0                                                            |   |                       |
| SENSOR\_CAPP | 6   | I    | GPIO37, ADC1\_CH1, RTC\_GPIO1                                                            |   |                       |
| SENSOR\_CAPN | 7   | I    | GPIO38, ADC1\_CH2, RTC\_GPIO2                                                            |   |                       |
| SENSOR\_VN   | 8   | I    | GPIO39, ADC1\_CH3, RTC\_GPIO3                                                            |   |                       |
| CHIP\_PU     | 9   | I    | High: On; enables the chip Low: Off; the chip powers off Note: Do not leave the          |   | CHIP\_PU pin floating |
| VDET\_1      | 10  | I    | GPIO34, ADC1\_CH6, RTC\_GPIO4                                                            |   |                       |
| VDET\_2      | 11  | I    | GPIO35, ADC1\_CH7, RTC\_GPIO5                                                            |   |                       |
| 32K\_XP      | 12  | I/O  | GPIO32, ADC1\_CH4, RTC\_GPIO9, TOUCH9, 32K\_XP (32.768 kHz crystal oscillator input)     |   |                       |
| 32K\_XN      | 13  | I/O  | GPIO33, ADC1\_CH5, RTC\_GPIO8, TOUCH8, 32K\_XN (32.768 kHz crystal oscillator output)    |   |                       |
| GPIO25       | 14  | I/O  | GPIO25, ADC2\_CH8, RTC\_GPIO6, DAC\_1, EMAC\_RXD0                                        |   |                       |
| GPIO26       | 15  | I/O  | GPIO26, ADC2\_CH9, RTC\_GPIO7, DAC\_2, EMAC\_RXD1                                        |   |                       |
| GPIO27       | 16  | I/O  | GPIO27, ADC2\_CH7, RTC\_GPIO17, TOUCH7, EMAC\_RX\_DV                                     |   |                       |
| MTMS         | 17  | I/O  | GPIO14, ADC2\_CH6, RTC\_GPIO16, TOUCH6, EMAC\_TXD2, HSPICLK, HS2\_CLK, SD\_CLK, MTMS     |   |                       |
| MTDI         | 18  | I/O  | GPIO12, ADC2\_CH5, RTC\_GPIO15, TOUCH5, EMAC\_TXD3, HSPIQ, HS2\_DATA2, SD\_DATA2, MTDI   |   |                       |
| VDD3P3\_RTC  | 19  | P    | Input power supply for RTC IO (2.3 V – 3.6 V)                                            |   |                       |
| MTCK         | 20  | I/O  | GPIO13, ADC2\_CH4, RTC\_GPIO14, TOUCH4, EMAC\_RX\_ER, HSPID, HS2\_DATA3, SD\_DATA3, MTCK |   |                       |
| MTDO         | 21  | I/O  | GPIO15, ADC2\_CH3, RTC\_GPIO13, TOUCH3, EMAC\_RXD3, HSPICS0, HS2\_CMD, SD\_CMD, MTDO     |   |                       |
| GPIO2        | 22  | I/O  | GPIO2, ADC2\_CH2, RTC\_GPIO12, TOUCH2, HSPIWP, HS2\_DATA0, SD\_DATA0                     |   |                       |
| GPIO0        | 23  | I/O  | GPIO0, ADC2\_CH1, RTC\_GPIO11, TOUCH1, EMAC\_TX\_CLK,CLK\_OUT1,                          |   |                       |
| GPIO4        | 24  | I/O  | GPIO4, ADC2\_CH0, RTC\_GPIO10, TOUCH0, EMAC\_TX\_ER, HSPIHD, HS2\_DATA1, SD\_DATA1       |   |                       |
| -            | -   | -    | **VDD\_SDIO**                                                                            |   |                       |
| GPIO16       | 25  | I/O  | GPIO16, HS1\_DATA4, U2RXD, EMAC\_CLK\_OUT                                                |   |                       |
| VDD\_SDIO    | 26  | P    | Output power supply: 1.8 V or the same voltage as VDD3P3\_RTC                            |   |                       |
| GPIO17       | 27  | I/O  | GPIO17, HS1\_DATA5, U2TXD, EMAC\_CLK\_OUT\_180                                           |   |                       |
| SD\_DATA\_2  | 28  | I/O  | GPIO9, HS1\_DATA2, U1RXD, SD\_DATA2, SPIHD                                               |   |                       |
| SD\_DATA\_3  | 29  | I/O  | GPIO10, HS1\_DATA3, U1TXD, SD\_DATA3, SPIWP                                              |   |                       |
| SD\_CMD      | 30  | I/O  | GPIO11, HS1\_CMD, U1RTS, SD\_CMD, SPICS0                                                 |   |                       |
| SD\_CLK      | 31  | I/O  | GPIO6, HS1\_CLK, U1CTS, SD\_CLK, SPICLK                                                  |   |                       |
| SD\_DATA\_0  | 32  | I/O  | GPIO7, HS1\_DATA0, U2RTS, SD\_DATA0, SPIQ                                                |   |                       |
| SD\_DATA\_1  | 33  | I/O  | GPIO8, HS1\_DATA1, U2CTS, SD\_DATA1, SPID                                                |   |                       |
| -            | -   | -    | **VDD3P3\_CPU**                                                                          |   |                       |
| GPIO5        | 34  | I/O  | GPIO5, HS1\_DATA6, VSPICS0, EMAC\_RX\_CLK                                                |   |                       |
| GPIO18       | 35  | I/O  | GPIO18, HS1\_DATA7, VSPICLK                                                              |   |                       |
| GPIO23       | 36  | I/O  | GPIO23, HS1\_STROBE, VSPID                                                               |   |                       |
| VDD3P3\_CPU  | 37  | P    | Input power supply for CPU IO (1.8 V – 3.6 V)                                            |   |                       |
| GPIO19       | 38  | I/O  | GPIO19, U0CTS, VSPIQ, EMAC\_TXD0                                                         |   |                       |
| GPIO22       | 39  | I/O  | GPIO22, U0RTS, VSPIWP, EMAC\_TXD1                                                        |   |                       |
| U0RXD        | 40  | I/O  | GPIO3, U0RXD, CLK\_OUT2                                                                  |   |                       |
| U0TXD        | 41  | I/O  | GPIO1, U0TXD, CLK\_OUT3, EMAC\_RXD2                                                      |   |                       |
| GPIO21       | 42  | I/O  | GPIO21, VSPIHD, EMAC\_TX\_EN                                                             |   |                       |
| -            | -   | -    | **Analog**                                                                               |   |                       |
| VDDA         | 43  | P    | Analog power supply (2.3 V – 3.6 V)                                                      |   |                       |
| XTAL\_N      | 44  | O    | External crystal output                                                                  |   |                       |
| XTAL\_P      | 45  | I    | External crystal input                                                                   |   |                       |
| VDDA         | 46  | P    | Analog power supply (2.3 V – 3.6 V)                                                      |   |                       |
| CAP2         | 47  | I    | Connects to a 3 nF capacitor and 20 kΩ resistor in parallel to CAP1                      |   |                       |
| CAP1         | 48  | I    | Connects to a 10 nF series capacitor to ground                                           |   |                       |
| GND          | 49  | P    | Ground                                                                                   |   |                       |

## 二、ESP32-WROOM-32D模组

ESP32-WROOM-32D(或32U)模组内置ESP32-D0WD双核芯片,40MHz晶振,32Mbit 3.3V flash 和板载天线.

### 1. ESP32-WROOM-32D模组特殊引脚&注意事项

* **遵循第一节ESP32-D2WD特殊引脚查询表&注意事项**

### 2. ESP32-WROOM-32D优先使用引脚

> **优先>不优先>不建议>禁用**

| 引脚名      | 芯片No. | 电源          | 是否建议使用 | 备注/原因              |
| -------- | ----- | ----------- | ------ | ------------------ |
| 模组左侧     | -     | -           | -      | -                  |
| GPIO34\* | 10    | VDD3P3\_RTC | 不建议    | 仅输入                |
| GPIO35\* | 11    | VDD3P3\_RTC | 不建议    | 仅输入                |
| GPIO32   | 12    | VDD3P3\_RTC | 优先     |                    |
| GPIO33   | 13    | VDD3P3\_RTC | 优先     |                    |
| GPIO25   | 14    | VDD3P3\_RTC | 优先     |                    |
| GPIO26   | 15    | VDD3P3\_RTC | 优先     |                    |
| GPIO27   | 16    | VDD3P3\_RTC | 优先     |                    |
| GPIO14   | 17    | VDD3P3\_RTC | 优先     | MTMS               |
| GPIO12\* | 18    | VDD3P3\_RTC | 不建议    | MTDI 用于选择 flash 电压 |
| 模组下侧     | -     | -           | -      | -                  |
| GPIO13   | 20    | VDD3P3\_RTC | 优先     | MTCK               |
| GPIO15\* | 21    | VDD3P3\_RTC | 不建议    | MTDO               |
| GPIO2\*  | 22    | VDD3P3\_RTC | 不建议    | 用于选择 boot mode     |
| 模组右侧     | -     | -           | -      | -                  |
| GPIO23   | 36    | VDD3P3\_CPU | 优先     |                    |
| GPIO22   | 39    | VDD3P3\_CPU | 优先     |                    |
| GPIO21   | 42    | VDD3P3\_CPU | 优先     |                    |
| GPIO19   | 38    | VDD3P3\_CPU | 优先     |                    |
| GPIO18   | 35    | VDD3P3\_CPU | 优先     |                    |
| GPIO5    | 34    | VDD3P3\_CPU | 优先     |                    |
| GPIO17\* | 27    | VDD\_SDIO   | 不优先    | 在该模组中未用于连接flash    |
| GPIO16\* | 25    | VDD\_SDIO   | 不优先    | 在该模组中未用于连接flash    |
| GPIO4    | 24    | VDD3P3\_RTC | 优先     |                    |
| GPIO0\*  | 23    | VDD3P3\_RTC | 不建议    | 用于选择 boot mode     |

### 3. ESP32-WROOM-32D模组封装

![ESP32-WROOM-32D 管脚布局顶视图](https://img-blog.csdnimg.cn/20191120142225366.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzIwNTE1NDYx,size_16,color_FFFFFF,t_70)

### 4. ESP32-WROOM-32D模组引脚定义

名称 | 编号 | 类型 | 功能 |--|--|--|--| GND|1|P|接地 3V3|2|P|供电 EN|3|I|使能模组,高电平有效. SENSOR\_VP|4|I|GPIO36,ADC1\_CH0,RTC\_GPIO0 SENSOR\_VN|5|I|GPIO39,ADC1\_CH3,RTC\_GPIO3 IO34|6|I|GPIO34,ADC1\_CH6,RTC\_GPIO4 IO35|7|I|GPIO35,ADC1\_CH7,RTC\_GPIO5 IO32|8|I/O|GPIO32,XTAL\_32K\_P(32.768kHz晶振输入),ADC1\_CH4,TOUCH9,RTC\_GPIO9 IO33|9|I/O|GPIO33,XTAL\_32K\_N(32.768kHz晶振输出),ADC1\_CH5,TOUCH8,RTC\_GPIO8 IO25|10|I/O|GPIO25,DAC\_1,ADC2\_CH8,RTC\_GPIO6,EMAC\_RXD0 IO26|11|I/O|GPIO26,DAC\_2,ADC2\_CH9,RTC\_GPIO7,EMAC\_RXD1 IO27|12|I/O|GPIO27,ADC2\_CH7,TOUCH7,RTC\_GPIO17,EMAC\_RX\_DV IO14|13|I/O|GPIO14,ADC2\_CH6,TOUCH6,RTC\_GPIO16,MTMS,HSPICLK,HS2\_CLK,SD\_CLK,EMAC\_TXD2 IO12|14|I/O|GPIO12,ADC2\_CH5,TOUCH5,RTC\_GPIO15,MTDI,HSPIQ,HS2\_DATA2,SD\_DATA2,EMAC\_TXD3 GND|15|P|接地 IO13|16|I/O|GPIO13,ADC2\_CH4,TOUCH4,RTC\_GPIO14,MTCK,HSPID,HS2\_DATA3,SD\_DATA3,EMAC\_RX\_ER SHD/SD2*|17|I/O|GPIO9,SD\_DATA2,SPIHD,HS1\_DATA2,U1RXD SWP/SD3*|18|I/O|GPIO10,SD\_DATA3,SPIWP,HS1\_DATA3,U1TXD SCS/CMD*|19|I/O|GPIO11,SD\_CMD,SPICS0,HS1\_CMD,U1RTS SCK/CLK*|20|I/O|GPIO6,SD\_CLK,SPICLK,HS1\_CLK,U1CTS SDO/SD0*|21|I/O|GPIO7,SD\_DATA0,SPIQ,HS1\_DATA0,U2RTS SDI/SD1*|22|I/O|GPIO8,SD\_DATA1,SPID,HS1\_DATA1,U2CTS IO15|23|I/O|GPIO15,ADC2\_CH3,TOUCH3,MTDO,HSPICS0,RTC\_GPIO13,HS2\_CMD,SD\_CMD,EMAC\_RXD3 IO2|24|I/O|GPIO2,ADC2\_CH2,TOUCH2,RTC\_GPIO12,HSPIWP,HS2\_DATA0,SD\_DATA0 IO0|25|I/O|GPIO0,ADC2\_CH1,TOUCH1,RTC\_GPIO11,CLK\_OUT1,EMAC\_TX\_CLK IO4|26|I/O|GPIO4,ADC2\_CH0,TOUCH0,RTC\_GPIO10,HSPIHD,HS2\_DATA1,SD\_DATA1,EMAC\_TX\_ER IO16|27|I/O|GPIO16,HS1\_DATA4,U2RXD,EMAC\_CLK\_OUT IO17|28|I/O|GPIO17,HS1\_DATA5,U2TXD,EMAC\_CLK\_OUT\_180 IO5|29|I/O|GPIO5,VSPICS0,HS1\_DATA6,EMAC\_RX\_CLK IO18|30|I/O|GPIO18,VSPICLK,HS1\_DATA7 IO19|31|I/O|GPIO19,VSPIQ,U0CTS,EMAC\_TXD0 NC|32|-|- IO21|33|I/O|GPIO21,VSPIHD,EMAC\_TX\_EN RXD0|34|I/O|GPIO3,U0RXD,CLK\_OUT2 TXD0|35|I/O|GPIO1,U0TXD,CLK\_OUT3,EMAC\_RXD2 IO22|36|I/O|GPIO22,VSPIWP,U0RTS,EMAC\_TXD1 IO23|37|I/O|GPIO23,VSPID,HS1\_STROBE GND|38|P|接地

### 5. ESP32-WROOM-32D模组原理图

[参考文档:esp32-wroom-32d\_esp32-wroom-32u\_datasheet\_cn.pdf ](https://www.espressif.com/sites/default/files/documentation/esp32-wroom-32d_esp32-wroom-32u_datasheet_cn.pdf)

![ESP32-WROOM-32D 电路原理图](https://img-blog.csdnimg.cn/20191120140310278.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzIwNTE1NDYx,size_16,color_FFFFFF,t_70)

![ESP32-WROOM-32D 电路原理图 A](https://img-blog.csdnimg.cn/20191120140914803.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzIwNTE1NDYx,size_16,color_FFFFFF,t_70)

![ESP32-WROOM-32D 电路原理图 B](https://img-blog.csdnimg.cn/20191120141027426.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzIwNTE1NDYx,size_16,color_FFFFFF,t_70)

### 6. ESP32-WROOM-32D外围原理图参考设计

![ESP32-WROOM-32D 外围原理图](https://img-blog.csdnimg.cn/20191120141400448.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzIwNTE1NDYx,size_16,color_FFFFFF,t_70)