ESP32 Thing Power Control Shield Hookup Guide
Alex the Giant 
Hardware Overview
The ESP32 Thing Power Control Shield has a voltage range of 5-28VDC. Power can be connected in one of two ways. The first is the barrel connector, but with a maximum current rating of 2.5A it's really only meant for light loads. The second option is on the three pin screw terminal (rated at 6A), which has connections for VCC, ground, and a 5V output. The supply voltage is regulated down to 5V to power the ESP32 Thing, as well as a fan to keep the board cool under heavy loads.
At the heart of the board, is the MC33926 motor driver by NXP Semiconductors. The driver is capable of switching loads between 5-28VDC up to 5A. While the board is theoretically capable of switching up to 30A total, the power traces in the board and connectors have only been tested up to 10A total across the 6 outputs pins.
Along with switching DC loads on and off, the MC33926 also has three built in current sensors, which are connected to outputs 2, 4, and 6. Each of the current sensors are connected to a LMV358 operational amplifier to adjust the gain of each current measurement. For more details, refer to the Hardware Assembly section.
For a list of all connections to the ESP32 Thing, refer to the table below:
| ESP32 Thing Pin | Description |
|---|---|
| VUSB | 5V input to power ESP32 Thing. |
| 3V3 | 3.3V output to power MC33926 logic and LMV358 amplifiers. |
| GND | GND |
| 5 | Disable Outputs When HIGH, all outputs are have a high Z impedance. A 1 kΩ pull-down resistor enables all outputs by default. |
| 25 | Output 1 A logic HIGH pulls OUTPUT 1 to VCC and a logic LOW to GND. |
| 18 | Output 2 A logic HIGH pulls OUTPUT 2 to VCC and a logic LOW to GND. |
| 23 | Output 3 A logic HIGH pulls OUTPUT 3 to VCC and a logic LOW to GND. |
| 33 | Output 4 A logic HIGH pulls OUTPUT 4 to VCC and a logic LOW to GND. |
| 32 | Output 5 A logic HIGH pulls OUTPUT 5 to VCC and a logic LOW to GND. |
| 19 | Output 6 A logic HIGH pulls OUTPUT 6 to VCC and a logic LOW to GND. |
| 34 | Current Sense 2 0.24% of current on OUTPUT 2 |
| 39 | Current Sense 4 0.24% of current on OUTPUT 4 |
| 36 | Current Sense 6 0.24% of current on OUTPUT 6 |