Waveshare ESP32-C3-Zero

Tags: chip:ESP32-C3

The Waveshare ESP32-C3-Zero is a compact development board supplied by Waveshare.

../../../../../_images/ESP32-C3-Zero.jpg

Features

  • Low-power RISC-V 32-bit Single-core processor, up to 160MHz main frequency.

  • Supports 2.4GHz Wi-Fi (802.11 b/g/n) and Bluetooth® 5 (LE).

  • 400KB SRAM, 384KB ROM and built-in 4MB flash memory.

  • 15 multi-function GPIO pins.

  • 3× SPI, 1× I2C, 2× UART, 1× I2S, 2× ADC.

  • Onboard WS2812 RGB led.

  • Compact SMD ceramic antenna.

  • Ultra-compact size: 23.5 × 18 mm

Buttons and LEDs

There are two buttons labeled BOOT and RESET. The BOOT button is connected to GPIO9. On reset it is used as a strapping pin to determine whether the chip boots normally or into the serial bootloader. After reset, however, the BOOT button can be used for software input.

WS2812 LED is connected to GPIO10 and is available for software.

Pin Mapping

Pads numbered anticlockwise from USB connector.

Pad

Signal

Notes

1

5V

+5V Supply to board

2

GND

Ground

3

3V3

Power output to peripherals

4

GPIO0

5

GPIO1

6

GPIO2

7

GPIO3

8

GPIO4

SCK (bit-banging)

9

GPIO5

MISO (bit-banging)

10

GPIO6

MOSI (bit-banging)

11

GPIO7

CSn (bit-banging)

12

GPIO8

SCL (bit-banging)

13

GPIO9

SDA (bit-banging)

14

GPIO10

To connect with WS2812 RGB LED

15

GPIO18

USB_D+

16

GPIO19

USB_D-

17

GPIO20

Default RX for UART0 serial console

18

GPIO21

Default TX for UART0 serial console

Note

The Waveshare ESP32-C3-Zero does not have dedicated I2C and SPI pins. However, you can implement software-based I2C or SPI (bit-banging) using any available GPIO pins.

Power Supply

There are two mutually exclusive ways to provide power to the board:

  • USB Type-C Port

  • supplying via VIN (5V) pin (3.3–6 V) and GND pin headers

Installation & Build

For instructions on how to to install the build dependencies and create a NuttX image for this board, consult the main ESP32-C3 documentation.

Serial Console

A USB Serial Adapter is required to run NuttX on ESP32-C3-Zero with UART0 serial console.

Connect the USB Serial Adapter to ESP32-C3-Zero Serial Console at:

USB Serial connections

USB Serial

ESP32-C3-Zero Pin

GND

GND (Pin 2)

RX

GPIO21 (UART0 TX) (Pin 18)

TX

GPIO20 (UART0 RX) (Pin 17)

A USB serial adapter with +3.3V TTL level UART signals is required.

Connect ESP32-C3-Zero to our computer with the USB Serial Adapter. On our computer, start a Serial Terminal and connect to the USB Serial Port at 115200 bps.

NuttX will appear in the Serial Console when it boots on ESP32-C3-Zero.

Configurations

All configurations listed below can be configured using the following command in the nuttx directory (again, consult the main ESP32-C3 documentation):

$ ./tools/configure.sh esp32-c3-zero:<config_name>

where <config_name> is the name of board configuration you want to use, i.e.: nsh, usbnsh, wifi…

Build System

Build System

Support

Make

Yes

CMake

No

 
$ make flash ESPTOOL_PORT=/dev/ttyUSB0 -j

Then use a serial console terminal like picocom configured to 115200 8N1.

jumbo

This configuration enables many Apache NuttX features (console enabled in UART0, at 115200 bps). This is mostly to help provide additional code coverage in CI, but also allows for a users to see a wide range of features that are supported by the OS.

I2C

The I2C Tool can be used to scan and manipulate I2C devices. You can scan for all I2C devices using the following command:

nsh> i2c dev -b 3 00 77
NOTE: Some devices may not appear with this scan.
You may also try a scan with the -z flag to discover more devices using a zero-byte write request.
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- 76 --
nsh>

Tip

Please refer to I2C Tool for more information.

SPI

The SPI Tool provides a way to debug SPI related problems. You can test it by connecting MOSI and MISO pins which are GPIO6 and GPIO5 by default to each other and running the spi example:

nsh> spi exch -b 3 "AB"
Sending:    AB
Received:   AB

Tip

Please refer to SPI Tool for more information.

bmp280

You can check that the Bosch BMP280 sensor over I2C is working by using the bmp280 application:

BMP280 connections

BMP280

ESP32-C3-Zero Pin

VCC

3V3 OUT (Pin 3)

GND

GND (Pin 2)

SCL

GPIO8 (SCL) (Pin 12)

SDA

GPIO9 (SDA) (Pin 13)

 
nsh> bmp280
Absolute pressure [hPa] = 1003.359985
Temperature [C] = 18.969999

sensortest

You can check that the Bosch BMP280 sensor over I2C is working by using the sensortest application:

nsh> sensortest -n 10 baro0
SensorTest: Test /dev/uorb/sensor_baro0 with interval(1000000us), latency(0us)
baro0: timestamp:3449690000 value1:1023.23 value2:19.75
baro0: timestamp:3449690000 value1:1023.23 value2:19.75
baro0: timestamp:3449690000 value1:1023.23 value2:19.75
baro0: timestamp:3449690000 value1:1023.23 value2:19.75
baro0: timestamp:3449690000 value1:1023.23 value2:19.75
baro0: timestamp:3449700000 value1:1023.23 value2:19.75
baro0: timestamp:3449700000 value1:1023.23 value2:19.75
baro0: timestamp:3449710000 value1:1022.82 value2:19.86
baro0: timestamp:3449710000 value1:1022.82 value2:19.86
baro0: timestamp:3449720000 value1:1022.82 value2:19.86
SensorTest: Received message: baro0, number:10/10
nsh>

nsh

Basic configuration that runs NuttShell (console enabled in UART0, at 115200 bps). This configuration is focused on low level, command-line driver testing. Built-in applications are supported, but none are enabled.

Tip

Please refer to NuttShell (NSH) for more information.

sta_softap

With this configuration you can run these commands to be able to connect your smartphone or laptop to your board:

nsh> ifup wlan1
nsh> dhcpd_start wlan1
nsh> wapi psk wlan1 mypasswd 3
nsh> wapi essid wlan1 nuttxap 1

In this case, you are creating the access point nuttxapp in your board and to connect to it on your smartphone you will be required to type the password mypasswd using WPA2.

Tip

Please refer to ESP32 Wi-Fi SoftAP Mode for more information.

The dhcpd_start is necessary to let your board to associate an IP to your smartphone.

usbnsh

Basic NuttShell configuration using CDC/ACM serial (console enabled in USB Port, at 115200 bps). This is another NSH example. If differs from other ‘nsh’ configurations in that this configurations uses a USB serial device for console I/O.

wifi

Enables Wi-Fi support. You can define your credentials this way:

$ make menuconfig
-> Application Configuration
    -> Network Utilities
        -> Network initialization (NETUTILS_NETINIT [=y])
            -> WAPI Configuration

Or if you don’t want to keep it saved in the firmware you can do it at runtime:

nsh> wapi psk wlan0 mypasswd 3
nsh> wapi essid wlan0 myssid 1
nsh> renew wlan0

Tip

Please refer to ESP32 Wi-Fi Station Mode for more information.