Merge branch 'main' of https://github.com/arduino/docs-content into mcmchris/opta/datasheet-cert-canada

Author: jcarolinares

content/arduino-cloud/07.api/02.arduino-iot-api/arduino-iot-api.md

@@ -78,13 +78,28 @@ Before we can make requests to the API, we will need to generate an **access tok
 
 ![Authorization (step 1).](assets/postman-1.png)
 
-Now, click on the **"Advanced Options"** tab, and add `https://api2.arduino.cc/iot` to the **"Audience"** field.
+- Set **"Auth Type"** to **"OAuth 2.0"** with a **"Request Header"**
+- Select **"Token Name"**, and **"Bearer"**
+
+Then scroll down to the **"Configure New Token"**.
 
 ![Authorization (step 2).](assets/postman-2.png)
 
-Finally, click on the **"Get New Access Token"**.
+- Set **"Grant Type"** to **"Client Credentials"** and set `https://api2.arduino.cc/iot/v1/clients/token` for the **"Access Token URL"**.
+- Add your Client ID & Client Secret (obtained in Arduino Cloud API Keys / Devices).
+- Set the **"Client Authentication"** to **"Send client credentials in body"**.
+
+Then, click on the **"Advanced"** tab, and populate the fields according to the image below:
+
+![Authorization (step 3).](assets/postman-3.png)
+
+- **Key** is set to `audience`
+- **Value** is set to `https://api2.arduino.cc/iot`
+- **Send In** is set to **Request Body**
+
+Finally, click on the **"Get New Access Token"**. You should get a pop-up window. On success, it should look like this:
 
-![Token button.](assets/access-token.png)
+![Authentication complete.](assets/auth-complete.png)
 
 You now have an access token that has an expiry of `300` seconds, and we can make requests to the API.
 

content/arduino-cloud/07.api/02.arduino-iot-api/assets/access-token.png

@@ -235,8 +235,8 @@ The SPI controller is by default assigned to the pins above.
 
 ### Universal Asynchronous Receiver/Transmitter (UART)
 
-- D0 / TX
-- D1 / RX
+- D1 / TX
+- D0 / RX
 
 The UART controller is by default assigned to the the pins above.
 
@@ -343,8 +343,8 @@ The GPIOs on the Nano ESP32 can handle **source currents** up to **40 mA**, and
 | 11  | D2           | Digital  | Digital pin 2                           |
 | 12  | GND          | Power    | Ground                                  |
 | 13  | RST          | Internal | Reset                                   |
-| 14  | D1/RX        | Digital  | Digital pin 1 / Serial Receiver (RX)    |
-| 15  | D0/TX        | Digital  | Digital pin 0 / Serial Transmitter (TX) |
+| 14  | D0/RX        | Digital  | Digital pin 1 / Serial Receiver (RX)    |
+| 15  | D1/TX        | Digital  | Digital pin 0 / Serial Transmitter (TX) |
 
 \*CIPO/COPI/CS replaces the MISO/MOSI/SS terminology.
 
@@ -738,8 +738,8 @@ SDA 和 SCL 引脚可分配给大多数 GPIO，但其中一些引脚可能具有
 
 ### 通用异步接收器/发射器 (UART)
 
-- D0 / TX
-- D1 / RX
+- D1 / TX
+- D0 / RX
 
 默认情况下，UART 控制器分配给上述引脚。
 
@@ -846,8 +846,8 @@ Nano ESP32 上的 GPIO 可处理的**源电流**最高达**40 mA**，**灌电流
 | 11  | D2           | 数字  | 数字引脚 2                           |
 | 12  | GND          | 电源    | 接地                                  |
 | 13  | RST          | 内部 | 复位                                   |
-| 14  | D1/RX        | 数字  | 数字引脚 1 /串行接收器 (RX)    |
-| 15  | D0/TX        | 数字  | 数字引脚 0 / 串行发射器 (TX) |
+| 14  | D0/RX        | 数字  | 数字引脚 1 /串行接收器 (RX)    |
+| 15  | D1/TX        | 数字  | 数字引脚 0 / 串行发射器 (TX) |
 
 \*CIPO/COPI/CS 取代 MISO/MOSI/SS 术语。
 

content/arduino-cloud/07.api/02.arduino-iot-api/assets/auth-complete.png

@@ -16,4 +16,5 @@ ser
 Manuel
 technic
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-forsee
+forsee
+classe