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Description

The breakout board provides a prototyping area allowing quick connections to allow debugging your circuit using the WiPhone's onboard processor, buttons, and display. Or expand the capabilities of the phone with your own sensor, input device, or other custom circuit.

This daughter board can be populated with a 3.3V/4.2V/5V power option to do testing with wide range of circuits.

Features

  • 30 rows of double 4-hole rows
  • 4 power rails with positive/negative markings
  • 1.2mm / 0.047" drill holes (accepts most DIP packages)
  • Pogo pin to 2*10 2.54mm / 0.1" pitch Through hole connector for prototyping.
  • 3.3V/4.2V/5V on-board power option

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Technical Details

_images/Backpack_legends.png

Peripherals and GPIO

Peripheral Type Qty Input(I) / Output(O)
Digital 11 I/O
Digital 1 I
Analog (ADC) 5 I
UART 1 I/O
SPI 1 I/O
I2C 1 I/O
USB-UART 1 I/O
PWM 11 O

Note

All GPIOs are rated at 3.3VDC max. For more details please check ESP32 and SX1509 datasheet.

Pinout

_images/Backpack_pinout.png

Tip

Right click and open image in new tab to have a better look.

Pin Description
5V This pin is internally connected to the VBUS of USB port.
VBAT This pin is internally connected to the positive terminal of the LiPo battery connector.
3.3V This pin is connected to the dedicated on board voltage regulator for daughter board.
GND This pin is connectoned to System GND.
DB_RXD Software UART. Connected to Mainboard RX.Can be used as DIGITAL INPUT PIN(GPI_38)
DB_TXD Software UART. Connected to Maiboard TX.Can be used as DIGITAL PIN(GPIO_32), ANALOG PIN (ADC1_CH4) and PWM PIN
DB_SPI_MISO MISO for Daughter board SPI. Can be used as DIGITAL PIN(GPIO_12) ANALOG PIN (ADC2_CH5) and PWM PIN.
DB_SPI_MOSI MOSI for Daughter board SPI. Can be used as DIGITAL PIN(GPIO_13), ANALOG PIN (ADC2_CH4) and PWM PIN.
DB_SPI_CLK Clock for Daughter board SPI. Can be used as DIGITAL PIN(GPIO_14), ANALOG PIN (ADC2_CH6) and PWM .
DB_SPI_CS CS for Daughter board SPI. Can be used as DIGITAL PIN(GPIO_27), ANALOG PIN (ADC2_CH7) and PWM PIN.
I2C_SCL Clock pin for I2C.Not recommended for any other function.
I2C_SDA Data pin for I2C.Not recommended for any other function.
D0-D5 These pins are generic IO pins connected to SX1509 IO expander

Warning

  1. The default drive strength of the ESP32 digital output pin is ~10mA.
  2. The default drive strength GPIO Expander digital output pin is ~8mA. Please refer to ESP32 and SX1509 datasheets for further detail.

5V PIN

The pin is internally connected to the VBUS of the USB port. The nominal output should be around 4.5 to 5 VDC when the device is plugged into the USB port and 0 when not connected to a USB source. You can use this pin to power peripherals that operate at such voltages. Do not exceed the current rating of the USB port, which is nominally rated to 500mA. This pin is also protected with an internal fuse rated at 1000mA.

VBAT Pin

This pin is internally connected to the positive pin LiPo Battery. Output voltage range on this pin is 3.4 to 4.2 VDC.

3.3V PIN

This pin is the output of the on board 3.3V LDO regulator (MIC5219-3.3BM5). The MIC5219 is designed for 150 mA to 200 mA output current applications where a high-current spike (500 mA) is needed for short, start-up conditions. Use can use this to power 3.3V devices.

Input only pins

GPIOs 34 to 39 are GPIs – input only pins. These pins don’t have internal pull-ups or pull-down resistors. They can’t be used as outputs, so use these pins only as inputs:

  • DB_RXD (GPI 38)

HSPI

  • DB_SPI_MISO(GPIO_12) MISO for Daughter board SPI.
  • DB_SPI_MOSI(GPIO_13) MOSI for Daughter board SPI.
  • DB_SPI_CLK(GPIO_14) Clock for Daughter board SPI.
  • DB_SPI_CS(GPIO_27) CS for Daughter board SPI.

I2C

The ESP32 has two I2C channels and any pin can be set as SDA or SCL. When using the ESP32 with the WiPhone Board in Arduino IDE, the default I2C pins are:

  • I2C_SDA (GPIO 15)
  • I2C_SCL (GPIO 25)

Note

Don't Use I2C Pins for any other function .These Pins are connected to the I2C devices on the Phone and are not recommended for other functions.

UART (Serial)

  • DB_TXD (GPIO 32)
  • DB_RXD (GPI 38)

Note

DB_RXD and DB_TXD are Software UART

Analog to Digital Converter (ADC)

The ESP32 has 18 x 12 bits ADC input channels . These are the GPIOs that can be used as ADC and respective channels:

  • DB_SPI_CS -> ADC2_CH7 (GPIO 27)
  • DB_SPI_MOSI -> ADC2_CH4 (GPIO 13)
  • DB_SPI_MISO -> ADC2_CH5 (GPIO 12)
  • DB_SPI_CLK -> ADC2_CH6 (GPIO 14)
  • DB_TXD -> ADC1_CH4 (GPIO 32)
  • DB_RXD -> ADC1_CH2 (GPI 38)

Pins HIGH at Boot

Some GPIOs change its state to HIGH or output PWM signals at boot or reset. This means that if you have outputs connected to these GPIOs you may get unexpected results when the ESP32 resets or boots.

  • DB_SPI_CLK (GPIO_14)

Interrupts

All GPIOs can be configured as interrupts.