Wrover32 based LED controller for NeoPixels and DotStars with 5v signalling and micro SD

Power:

This board is powered by 5V and generates a 3.3V supply via U1. This board may draw up to 500ma of current at 5V. The 3.3V supply is capable of generating up to 1A.

This board makes use of a Torex Semiconductor XCL220 micro DC/DC converter to efficiently provide 3.3v of power. This inexpensive device is reportedly 93% efficient which should increase battery life and reduce heat buildup.

Do not draw more than 500ma from any single power or ground pin on J2 or J4.

On J5, VBUS is 5V as are pins 9 and 12 on J4 and pin 1 on J2. J6 and J7 also provide +5V at the + terminal.

5V may be shunted through the board, but limit the current to no more than 2A.

5V may be supplied by any pin, however power provided by the micro SD connector J3 should be limited to 500 ma.

USB:

There are two USB connectors on the board for programming. The Micro USB connector J3 or J5 may be used. Do not use both connectors. J5 is designed so either a 4 pin header or a USB cable can be soldered to the board, eliminating the need to use micro USB.

The USB port is connected to a SI Labs CP2102 USB to serial UART for programming and debugging purposes.

I/O:

Unlike most if not all other ESP32 based boards, this board includes a 3V to 5V bidirectional level shifter for IO25, IO26, IO32 and IO33. These I/O ports can also be driven by the RTC in the ESP32 to help offload driving NeoPixels.

I/O27 is connected to an on-board SK6812MINI RGB NeoPixel with the output connected to J2 pin 4.

Connectors:

J1: Micro SD connector

J2: 1 - VBUS (+5V) 2 - GND 3 - +3.3V 4 - DO - Output from on-board NeoPixel 5 - IO34 6 - IO33_H - IO33 at 5v signalling 7 - IO32_H - IO32 at 5V signalling 8 - IO18_H - IO18 at 5V signalling 9 - IO5_H - IO5 at 5V signalling 10 - SENSOR_VN - Input to Sensor_VN pin 11 - SENSOR_VP - Input to Sensor_VP pin 12 - Reset

J3: Micro USB connector

J4: 1 - IO23 (10K pullup) 2 - IO22 (10K pullup) 3 - IO21 (10K pullup) 4 - IO19 5 - IO26 6 - IO25 7 - IO35 8 - IO0 9 - +3.3V 10 - GND 11 - GND 12 - VBUS (+5V)

J5: USB 1 - VBUS (+5) (3A input capable) 2 - D- 3 - D+ 4 - GND

J6: 1 - GND 2 - VBUS (+5V)

J7: 1 - GND 2 - VBUS (+5V) 3 - FET connected to ground, driven by IO26 (max 1A, 12V)

J8: 1 - GND 2 - IO23 (pullup) same as J4-1 3 - IO22 (pullup) same as J4-2 4 - IO21 (pullup) same as J4-3 5 - +3.3V

J9: 1 - GND 2 - +5V (3A input capable)

J11: 1 - Speaker + 2 - Speaker -

J101: Note: pins 1 and 2 are the opposite of other power connectors 1 - +12V 400ma 2 - GND

I2C: I2C is supported on pins IO21, IO22 and IO23, though one of those pins can also be used for a shared interruput line.

Notes: Some pins serve multiple purposes. For example, two of the 5V I/O pins are shared. For example, IO5 is also connected to the FET for PWM and IO33 is also connected to the BCLK on the amplifier. If these are used, do not use the 5V I/Os for IO5 and/or IO33. If IO33 is used, do not hook up a speaker.

IO18 and IO32 are dedicated for 5V I/O and IO27 is dedicated for the status LED and the output of that is useable for driving WS2812s or compatible 24-bit LEDs.

Power:

This board uses a Torex Semiconductor XCL220 buck converter to efficiently generate 3.3v with an output capability of up to 1A. It supports automatic shutdown for thermal, overcurrent and under voltage events.

Any VBUS (+5V) pin many be used to deliver or draw 5V from the board. Total current should not exceed 2A for all combined ground and +5V pins, however for power input connectors J5 and J9 are capable of handling 3A in order to supply the 12V booster

Ground: Any GND pin can be used for ground.

+3.3V The on-board power supply is capable of generating up to 1A. The Wrover32 can consume up to 500ma. Please limit power consumption to no more than 200ma to be safe.

+12V This board includes a 5V to 12V boost circuit in order to provide power to a fan or other accessories via J101. Do not exceed 400ma. All components needed for the 12V boost circuit start at reference 100. To disable 12V support, do not install any components in this range, i.e. J101, R101, etc.

RESET:

This board can be reset in one of three ways. The serial UART, SW1 and J2 pin 12 can all be used to reset the board. To reset the board using J2, pull the RESET line to ground.

5V logic

This board is designed to be able to drive 5 channels of NeoPixels, or two channels of DotStars and one channel of NeoPixels. One NeoPixel (D1) is built-in to the board and the output is connected to J2 pin 4. The other four channels are pins J2 6, 7, 8 and 9. Note that D1 uses a WS2813B-Mini.

Connectors J2 and J4:

Connectors J2 and J4 and JST VM12B-SRSS-TB connectors and mate with the JST 12SR-3S connector. These connectors can be found at Digikey, including connectors with wires already installed. Note that the wire for the mating connectors is a bit hard to find. Alpha Wire 2928 WH005 fits this connector. It is a bit pricy. Mouser has it cheaper than Digikey for $35/100 feet, though I also found it online for $25. The connector requires 7 strand wire with an outer diameter between 0.54 and 0.58mm.

Connectors J5 and J101 are JST PH series connectors which are readily available. J101 is not at all uncommon for computer fans.

All other connectors are pin headers with 1.27mm pitch, which is half the normal 2.54mm pitch except for J9, which uses the 2.54mm pitch.

USB: Use either a micro USB cable OR J5, do not use both for USB I/O. Both, however, are safe for power and ground, however do not exceed 900ma when using a micro USB cable.

Microphone:

An optional SPH0645LM4H-B i2s compatible microphone is available. If present, it is configured for the left channel. Word-select is on IO5, clock is on IO0 and data is on IO35.

Fan control: The PWM pin is not near the 12v supply due to routing issues. In order to use PWM support, the fan must be connected to +12 or +5 and the PWM pin (J7 pin 3) for ground. Note that J7 pin 3 should never be shorted to ground as this will cause Q4 to act as a diode and likely burn up.

Booting and programming: This follows the model used on the Wrover development board where DTR and RTS are used to control IO0, IO2 and RESET. Note that revision 1.5 and later fixes the programming by supporting IO2. IO2 is new for the Wrover32 and is not used by the Wroom32.

GPIOs: IO0: I2S-BCLK, RTS for programming, J4-8 IO2: SD-DAT0, RTS for programming IO4: SD-DAT1 IO5: 5V I/O, FAN PWM IO12: SD-DAT2 IO13: SD-DAT3/CD IO14: SD-Clock IO15: SD-Command IO16: do not use IO17: do not use IO18: 5V I/O IO19: mic I2S-WS, JU4-4 IO21: Pull-up, J4-3, SDA IO22: Pull-up, J4-2, SCL IO23: Pull-up, J4-1, /INT IO25: J4-6, Speaker DIN IO26: J4-5, Speaker BCLK IO27: Status RGB LED output IO32: 5V I/O IO33: 5V I/O, Speaker LRCLK IO34: J2-5 (input only) IO35: MIC I2S-data in, J4-7 SENSOR_VP: J2-11 SENSOR_VN: J2-10