Changes in 05d9eed: usb

				Tech-dat/Interface-dat/USB-SDK-dat/USB-type-c-dat/USB-type-c-dat.md
			
          @@ -16,6 +16,8 @@

           - [[USB-OTG-dat]]

          +- [[displayport-dat]] - [[audio-dat]]

          +

           ## apps 

           - [[type-c-to-ethernet-dat]]

          @@ -134,6 +136,64 @@ If you are DIY-ing a power source and want the phone to recognize the 5V supply,

           * **Voltage Sag:** If your 5V source isn't stable, the phone might repeatedly connect and disconnect as the voltage drops under load.

           * **Heat:** Cheap DIY connections can have high resistance, leading to heat at the connector.

          +

          +### SBU SDK info 

          +

          +Repurposing USB-C SBU Wires

          +

          +In the USB-C standard, **SBU1** and **SBU2** are "extra" wires. While they were originally intended for DisplayPort or Analog Audio, they are perfect for adding custom features to a small robot like your [[ESP32-S3-dat]] quadruped. - [[robotic-dat]]

          +

          +#### 1. Electrical Constraints (Safety First)

          +| Constraint | Limit | Reason |

          +| :--- | :--- | :--- |

          +| **Max Voltage** | **3.3V** | SBU wires connect to ESP32 GPIOs; 5V will fry them. |

          +| **Max Current** | **< 50mA** | These wires are extremely thin (30-32 AWG). |

          +| **Best For** | **Logic Signals** | Buttons, I2C, UART, or Analog Sensors. |

          +| **Avoid** | **Power Delivery** | Never use SBU to power servos or bright LEDs. |

          +

          +---

          +

          +#### 2. Practical DIY Examples

          +

          +##### A. External "Kill-Switch" (Safety)

          +If your robot's gait code fails and it starts running into a wall:

          +- **Wiring:** Connect a button between **SBU1** and **GND** at the cable end.

          +- **Code:** Set the ESP32 pin to `INPUT_PULLUP`. 

          +- **Action:** If the pin goes `LOW`, the code stops all servos immediately.

          +

          +##### B. Remote I2C Debugging Screen

          +Since your robot is small and space is limited, you can keep the screen outside the robot:

          +- **Wiring:** Use **SBU1 for SDA** and **SBU2 for SCL**.

          +- **Usage:** Connect a tiny 0.91" OLED display to the end of your USB cable.

          +- **Benefit:** You can read real-time "Leg Degrees" or "Battery Voltage" while the robot moves.

          +

          +##### C. Remote "Boot" or "Reset" Button

          +If the ESP32-S3 is hidden inside a chassis:

          +- **Wiring:** Connect **SBU1** to the **EN (Reset)** pin or **BOOT (GPIO 0)** pin.

          +- **Benefit:** You can put the robot into "Upload Mode" or Reset it without opening the shell.

          +

          +---

          +

          +#### 3. Using SBU for Audio (Important Logic)

          +While a PC will not "read" analog audio from SBU pins automatically, you can 

          +build a custom point-to-point system:

          +

          +- **Legacy Audio Mode:** In custom hardware, **SBU1** is often used for the 

          +  **Microphone** signal and **SBU2** for **Analog Ground**.

          +- **DIY Implementation:** 1. Send a low-voltage analog signal from a microphone through SBU1.

          +  2. Use an ADC (Analog-to-Digital Converter) pin on the ESP32-S3 to read it.

          +  3. **Note:** You must use a **0.1µF capacitor** to filter out the electrical 

          +     noise caused by your SG90 servos, as they share the same ground.

          +

          +---

          +

          +#### 4. How to Identify SBU Wires

          +Since manufacturers use different colors, use a Multimeter in "Continuity Mode":

          +1. Touch one probe to **Pin A8 (SBU1)** or **Pin B8 (SBU2)** on the USB-C plug.

          +2. Touch the other probe to the stripped wires until you hear a "Beep."

          +3. **Label them immediately** with tape to avoid mixing them up with VCC/GND.

          +

          +

           ## ref 

           - [[USB-type-c]]

          \ No newline at end of file

				Tech-dat/robotic-dat/robotic-dat.md
			
          @@ -12,6 +12,7 @@

           - [[Quadruped-Locomotion-dat]]

          +- quadruped

           ## Electronics

...	...	@@ -16,6 +16,8 @@
16	16
17	17	- [[USB-OTG-dat]]
18	18
	19	+- [[displayport-dat]] - [[audio-dat]]
	20	+
19	21	## apps
20	22
21	23	- [[type-c-to-ethernet-dat]]
...	...	@@ -134,6 +136,64 @@ If you are DIY-ing a power source and want the phone to recognize the 5V supply,
134	136	* Voltage Sag: If your 5V source isn't stable, the phone might repeatedly connect and disconnect as the voltage drops under load.
135	137	* Heat: Cheap DIY connections can have high resistance, leading to heat at the connector.
136	138
	139	+
	140	+### SBU SDK info
	141	+
	142	+Repurposing USB-C SBU Wires
	143	+
	144	+In the USB-C standard, SBU1 and SBU2 are "extra" wires. While they were originally intended for DisplayPort or Analog Audio, they are perfect for adding custom features to a small robot like your [[ESP32-S3-dat]] quadruped. - [[robotic-dat]]
	145	+
	146	+#### 1. Electrical Constraints (Safety First)
	147	+\| Constraint \| Limit \| Reason \|
	148	+\| :--- \| :--- \| :--- \|
	149	+\| Max Voltage \| 3.3V \| SBU wires connect to ESP32 GPIOs; 5V will fry them. \|
	150	+\| Max Current \| < 50mA \| These wires are extremely thin (30-32 AWG). \|
	151	+\| Best For \| Logic Signals \| Buttons, I2C, UART, or Analog Sensors. \|
	152	+\| Avoid \| Power Delivery \| Never use SBU to power servos or bright LEDs. \|
	153	+
	154	+---
	155	+
	156	+#### 2. Practical DIY Examples
	157	+
	158	+##### A. External "Kill-Switch" (Safety)
	159	+If your robot's gait code fails and it starts running into a wall:
	160	+- Wiring: Connect a button between SBU1 and GND at the cable end.
	161	+- Code: Set the ESP32 pin to `INPUT_PULLUP`.
	162	+- Action: If the pin goes `LOW`, the code stops all servos immediately.
	163	+
	164	+##### B. Remote I2C Debugging Screen
	165	+Since your robot is small and space is limited, you can keep the screen outside the robot:
	166	+- Wiring: Use SBU1 for SDA and SBU2 for SCL.
	167	+- Usage: Connect a tiny 0.91" OLED display to the end of your USB cable.
	168	+- Benefit: You can read real-time "Leg Degrees" or "Battery Voltage" while the robot moves.
	169	+
	170	+##### C. Remote "Boot" or "Reset" Button
	171	+If the ESP32-S3 is hidden inside a chassis:
	172	+- Wiring: Connect SBU1 to the EN (Reset) pin or BOOT (GPIO 0) pin.
	173	+- Benefit: You can put the robot into "Upload Mode" or Reset it without opening the shell.
	174	+
	175	+---
	176	+
	177	+#### 3. Using SBU for Audio (Important Logic)
	178	+While a PC will not "read" analog audio from SBU pins automatically, you can
	179	+build a custom point-to-point system:
	180	+
	181	+- Legacy Audio Mode: In custom hardware, SBU1 is often used for the
	182	+ Microphone signal and SBU2 for Analog Ground.
	183	+- DIY Implementation: 1. Send a low-voltage analog signal from a microphone through SBU1.
	184	+ 2. Use an ADC (Analog-to-Digital Converter) pin on the ESP32-S3 to read it.
	185	+ 3. Note: You must use a 0.1µF capacitor to filter out the electrical
	186	+ noise caused by your SG90 servos, as they share the same ground.
	187	+
	188	+---
	189	+
	190	+#### 4. How to Identify SBU Wires
	191	+Since manufacturers use different colors, use a Multimeter in "Continuity Mode":
	192	+1. Touch one probe to Pin A8 (SBU1) or Pin B8 (SBU2) on the USB-C plug.
	193	+2. Touch the other probe to the stripped wires until you hear a "Beep."
	194	+3. Label them immediately with tape to avoid mixing them up with VCC/GND.
	195	+
	196	+
137	197	## ref
138	198
139	199	- [[USB-type-c]]
...	...	\ No newline at end of file

...	...	@@ -12,6 +12,7 @@
12	12
13	13	- [[Quadruped-Locomotion-dat]]
14	14
	15	+- quadruped
15	16
16	17	## Electronics
17	18