Espressif ESP32-Sparrow

Tags: arch:xtensa chip:esp32 part:esp32wrover

The ESP32-Sparrow is a custom open-source development board for the ESP32 SoC, based on a ESP32-WROVER module. You can find the original V2 version and the newer V3 variant, based on a ESP32-C6 module. This page documents the original V2 version.

ESP32 Sparrow V2

ESP32 Sparrow V3

Features

• ESP32 WROVER Module

• USB-to-UART bridge via micro USB port

• BME680 temperature, humidity, pressure and air quality sensor

• LTR308 ambient light sensor/luxmeter

• 128x32 SSD1306 OLED

• RGB LED

• I2S Microphone

• Micro-SD Card Holder

• 18650 LiPo battery holder with charging circuit

• Expansion headers

Serial Console

The serial console will show up as /dev/ttyUSB[n] where [n] will probably be 0.

Buttons and LEDs

Board Buttons

There are two buttons labeled RST and BOOT. The RST button is not available to software. It pulls the chip enable line that doubles as a reset line.

The BOOT button is connected to IO0. 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.

Board LEDs

There are several on-board LEDs:

• Power and battery charge LED - Those are not available for use by software.

• RGB LED - Is available for use by software through GPIO pins.

GPIO Pin Mapping

Pin	Signal	Notes
GPIO0	BOOT	Connected to BOOT switch
GPIO2	SD_DATA0	SPI MISO / SDIO Data 0
GPIO4	SD_DATA1	SDIO Data 1 / General IO
GPIO5	SD_CS	SPI Chip Select for Micro-SD Card (SS)
GPIO12	SD_DATA2	SDIO Data 2 / MTDI
GPIO13	LED_G	Green channel for RGB LED
GPIO14	LED_R	Red channel for RGB LED
GPIO15	LED_B	Blue channel for RGB LED
GPIO18	SPI_SCK	SPI Clock for SD Card
GPIO19	SPI_MISO	SPI Data Input (MISO) for SD Card
GPIO21	I2C_SDA	I2C Data line (for BME680, LTR308, OLED)
GPIO22	I2C_SCL	I2C Clock line (for BME680, LTR308, OLED)
GPIO23	SPI_MOSI	SPI Data Output (MOSI) for SD Card
GPIO25	I2S_WS	LRCK for MEMS Microphone
GPIO26	I2S_SCK	BCLK for MEMS Microphone
GPIO35	I2S_SD	DIN for MEMS Microphone

Configurations

All of the configurations presented below can be tested by running the following commands:

$ ./tools/configure.sh esp32-sparrow:<config_name>
$ make flash ESPTOOL_PORT=/dev/ttyUSB0 -j

Where <config_name> is the name of board configuration you want to use, i.e.: nsh, wifi… Then use a serial console terminal like picocom configured to 115200 8N1.

ble

This configuration is used to enable Bluetooth Low Energy support for this board. You can scan for Bluetooth devices using the following commands:

NuttShell (NSH) NuttX-10.2.0
nsh> ifconfig
bnep0   Link encap:UNSPEC at DOWN
        inet addr:0.0.0.0 DRaddr:0.0.0.0 Mask:0.0.0.0
wlan0   Link encap:Ethernet HWaddr ac:67:b2:53:8b:ec at UP
        inet addr:10.0.0.2 DRaddr:10.0.0.1 Mask:255.255.255.0
nsh> bt bnep0 scan start
nsh> bt bnep0 scan stop
nsh> bt bnep0 scan get
Scan result:
1.     addr:           63:14:2f:b9:9f:83 type: 1
      rssi:            -90
      response type:   3
      advertiser data: 1e ff 06 00 01 09 20 02 7c 33 a3 a7 cd c9 44 5b
2.     addr:           52:ca:05:b5:ad:77 type: 1
      rssi:            -82
      response type:   3
      advertiser data: 1e ff 06 00 01 09 20 02 03 d1 21 57 bf 19 b3 7a
3.     addr:           46:8e:b2:cd:94:27 type: 1
      rssi:            -92
      response type:   2
      advertiser data: 02 01 1a 09 ff c4 00 10 33 14 12 16 80 02 0a d4
4.     addr:           46:8e:b2:cd:94:27 type: 1
      rssi:            -92
      response type:   4
      advertiser data: 18 09 5b 4c 47 5d 20 77 65 62 4f 53 20 54 56 20
5.     addr:           63:14:2f:b9:9f:83 type: 1
      rssi:            -80
      response type:   3
    advertiser data: 1e ff 06 00 01 09 20 02 7c 33 a3 a7 cd c9 44 5b

mqttc

This configuration tests the MQTT-C publisher example.

From the host, start the broker and subscribe to the test topic. Using mosquitto this should be:

$ mosquitto&
$ mosquitto_sub -t test

From the NSH, connect to an access point:

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

Publish to the broker:

nsh> mqttc_pub -h 192.168.1.11

The default behavior is to publish the message test. The following should be outputted:

nsh> mqttc_pub -h 192.168.1.11
     Success: Connected to broker!
     Success: Published to broker!

     Disconnecting from 192.168.1.11

From the host the message test should be outputted.

Apart from the -h option, there are multiple options that can be used with the publisher example:

Option	Default value	Description
-h	broker.hivemq.com	Set the host (broker) IP
-p	1883 or 8883	Set port value
-m	“test”	Message to be sent
-t	test	Set topic value
-n	1	Number of times to publish
-q	0	QoS (Quality of Service) level
-c		Certificate file (only for TLS connection)

nsh

Basic NuttShell configuration (console enabled in UART0, exposed via USB connection by means of CP2102 converter, at 115200 bps).

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.