ESP32-C3 DevKit
The ESP32-C3 DevKit is an entry-level development board equipped with either an ESP32-C3-WROOM-02 or an ESP32-C3-MINI-1. ESP32-C3-WROOM-02 and ESP32-C3-MINI-1 are SoMs based on the RISC-V ESP32-C3 CPU.
Most of the I/O pins are broken out to the pin headers on both sides for easy interfacing. Developers can either connect peripherals with jumper wires or mount ESP32-C3 DevKit on a breadboard.
ESP32-C3-DevKitC-02 |
ESP32-C3-DevKitM-1 |
Configurations
All of the configurations presented below can be tested by running the following commands:
$ ./tools/configure.sh esp32c3-generic:<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, buttons, wifi…
Then use a serial console terminal like picocom configured to 115200 8N1.
ble
This configuration is used to enable the Bluetooth Low Energy (BLE) of ESP32-C3 chip.
To test it, just run the following commands below.
Confirm that bnep interface exist:
nsh> ifconfig
bnep0 Link encap:UNSPEC at DOWN
inet addr:0.0.0.0 DRaddr:0.0.0.0 Mask:0.0.0.0
Get basic information from it:
nsh> bt bnep0 info
Device: bnep0
BDAddr: 86:f7:03:09:41:4d
Flags: 0000
Free: 20
ACL: 20
SCO: 0
Max:
ACL: 24
SCO: 0
MTU:
ACL: 70
SCO: 70
Policy: 0
Type: 0
Start the scanning process:
nsh> bt bnep0 scan start
Wait a little bit before stopping it.
Then after some minutes stop it:
nsh> bt bnep0 scan stop
Get the list of BLE devices found around you:
nsh> bt bnep0 scan get
Scan result:
1. addr: d7:c4:e6:xx:xx:xx type: 0
rssi: -62
response type: 4
advertiser data: 10 09 4d 69 20 XX XX XX XX XX XX XX XX XX XX 20 e
2. addr: cb:23:18:xx:xx:xx type: 0
rssi: -60
response type: 0
advertiser data: 02 01 06 1b ff XX XX XX ff ff ff ff ff ff ff ff 8
3. addr: cb:23:18:xx:xx:xx type: 0
rssi: -60
response type: 4
advertiser data: 10 09 4d 69 20 XX XX XX XX XX XX XX XX XX XX 20 e
4. addr: d7:c4:e6:xx:xx:xx type: 0
rssi: -62
response type: 0
advertiser data: 02 01 06 1b ff XX XX XX ff ff ff ff ff ff ff ff e
5. addr: d7:c4:e6:xx:xx:xx type: 0
rssi: -62
response type: 4
advertiser data: 10 09 4d 69 20 XX XX XX XX XX XX XX XX XX XX 20 e
nsh>
bmp180
This configuration enables the use of the BMP180 pressure sensor over I2C.
You can check that the sensor is working by using the bmp180 application:
nsh> bmp180
Pressure value = 91531
Pressure value = 91526
Pressure value = 91525
coremark
This configuration sets the CoreMark benchmark up for running on the maximum number of cores for this system. It also enables some optimization flags and disables the NuttShell to get the best possible score.
Note
As the NSH is disabled, the application will start as soon as the system is turned on.
efuse
This configuration demonstrates the use of the eFuse driver. It can be accessed
through the /dev/efuse device file.
Virtual eFuse mode can be used by enabling CONFIG_ESPRESSIF_EFUSE_VIRTUAL
option to prevent possible damages on chip.
The following snippet demonstrates how to read MAC address:
int fd;
int ret;
uint8_t mac[6];
struct efuse_param_s param;
struct efuse_desc_s mac_addr =
{
.bit_offset = 1,
.bit_count = 48
};
const efuse_desc_t* desc[] =
{
&mac_addr,
NULL
};
param.field = desc;
param.size = 48;
param.data = mac;
fd = open("/dev/efuse", O_RDONLY);
ret = ioctl(fd, EFUSEIOC_READ_FIELD, ¶m);
To find offset and count variables for related eFuse, please refer to Espressif’s Technical Reference Manuals.
gpio
This is a test for the GPIO driver. It uses GPIO1 and GPIO2 as outputs and GPIO9 as an interrupt pin.
At the nsh, we can turn the outputs on and off with the following:
nsh> gpio -o 1 /dev/gpio0
nsh> gpio -o 1 /dev/gpio1
nsh> gpio -o 0 /dev/gpio0
nsh> gpio -o 0 /dev/gpio1
We can use the interrupt pin to send a signal when the interrupt fires:
nsh> gpio -w 14 /dev/gpio2
The pin is configured as a rising edge interrupt, so after issuing the above command, connect it to 3.3V.
i2c
This configuration can be used to scan and manipulate I2C devices. You can scan for all I2C devices using the following command:
nsh> i2c dev 0x00 0x7f
nsh
Basic configuration to run the NuttShell (nsh).
ostest
This is the NuttX test at apps/testing/ostest that is run against all new
architecture ports to assure a correct implementation of the OS.
pwm
This configuration demonstrates the use of PWM through a LED connected to GPIO2.
To test it, just execute the pwm application:
nsh> pwm
pwm_main: starting output with frequency: 10000 duty: 00008000
pwm_main: stopping output
rmt
This configuration configures the transmitter and the receiver of the
Remote Control Transceiver (RMT) peripheral on the ESP32-C3 using GPIOs 8
and 2, respectively. The RMT peripheral is better explained
here,
in the ESP-IDF documentation. The minimal data unit in the frame is called the
RMT symbol, which is represented by rmt_item32_t in the driver:
The example rmtchar can be used to test the RMT peripheral. Connecting
these pins externally to each other will make the transmitter send RMT items
and demonstrates the usage of the RMT peripheral:
nsh> rmtchar
WS2812 addressable RGB LEDs
This same configuration enables the usage of the RMT peripheral and the example
ws2812 to drive addressable RGB LEDs:
nsh> ws2812
Please note that this board contains an on-board WS2812 LED connected to GPIO8 and, by default, this config configures the RMT transmitter in the same pin.
rtc
This configuration demonstrates the use of the RTC driver through alarms. You can set an alarm, check its progress and receive a notification after it expires:
nsh> alarm 10
alarm_daemon started
alarm_daemon: Running
Opening /dev/rtc0
Alarm 0 set in 10 seconds
nsh> alarm -r
Opening /dev/rtc0
Alarm 0 is active with 10 seconds to expiration
nsh> alarm_daemon: alarm 0 received
spi
This configuration enables the support for the SPI driver.
You can test it by connecting MOSI and MISO pins which are GPIO7 and GPIO2
by default to each other and running the spi example:
nsh> spi exch -b 2 "AB"
Sending: AB
Received: AB
If SPI peripherals are already in use you can also use bitbang driver which is a software implemented SPI peripheral by enabling CONFIG_ESPRESSIF_SPI_BITBANG option.
spiflash
This config tests the external SPI that comes with the ESP32-C3 module connected through SPI1.
By default a SmartFS file system is selected. Once booted you can use the following commands to mount the file system:
nsh> mksmartfs /dev/smart0
nsh> mount -t smartfs /dev/smart0 /mnt
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.
timer
This config test the general use purpose timers. It includes the 4 timers, adds driver support, registers the timers as devices and includes the timer example.
To test it, just run the following:
nsh> timer -d /dev/timerx
Where x in the timer instance.
twai
This configuration enables the support for the TWAI (Two-Wire Automotive Interface) driver.
You can test it by connecting TWAI RX and TWAI TX pins which are GPIO0 and GPIO2 by default
to an external transceiver or connecting TWAI RX to TWAI TX pin by enabling
the CONFIG_CAN_LOOPBACK option (Device Drivers -> CAN Driver Support -> CAN loopback mode)
and running the can example:
nsh> can
nmsgs: 0
min ID: 1 max ID: 2047
Bit timing:
Baud: 1000000
TSEG1: 15
TSEG2: 4
SJW: 3
ID: 1 DLC: 1
usbconsole
This configuration tests the built-in USB-to-serial converter found in ESP32-C3 (revision 3).
esptool can be used to check the version of the chip and if this feature is
supported. Running esptool.py -p <port> chip_id should have Chip is
ESP32-C3 (revision 3) in its output.
When connecting the board a new device should appear, a /dev/ttyACMX on Linux
or a /dev/cu.usbmodemXXX om macOS.
This can be used to flash and monitor the device with the usual commands:
make download ESPTOOL_PORT=/dev/ttyACM0
minicom -D /dev/ttyACM0
watchdog
This configuration tests the watchdog timers. It includes the 2 MWDTS, adds driver support, registers the WDTs as devices and includes the watchdog example application.
To test it, just run the following command:
nsh> wdog -i /dev/watchdogX
Where X is the watchdog instance.
To test the XTWDT(/dev/watchdog3) an interrupt handler needs to be implemented because XTWDT does not have system reset feature. To implement an interrupt handler WDIOC_CAPTURE command can be used. When interrupt rises, XTAL32K clock can be restored with WDIOC_RSTCLK command.
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.