Implementation of the VL53L0X: Time Of Flight Sensor from ST on the ST Disco L475 IOT01 board with Zephyr RTOS and Golioth Database.

• Build with west build -b disco_l475_iot1 -p -- -DSHIELD=esp_8266_arduino
• Flash with west flash
• • See output of UART

VL53L0X: Time Of Flight sensor

Overview

This sample periodically measures distance between vl53l0x sensor and target. The result is displayed on the console. It also shows how we can use the vl53l0x as a proximity sensor.

Requirements

This sample uses the VL53L0X sensor controlled using the I2C interface.

References

• VL53L0X: http://www.st.com/en/imaging-and-photonics-solutions/vl53l0x.html

Building and Running

This project outputs sensor data to the console. It requires a VL53L0X sensor, which is present on the disco_l475_iot1 board.

.. zephyr-app-commands::
   :app: samples/sensor/vl53l0x/
   :goals: build flash

Sample Output

prox is 0
distance is 1938
prox is 1
distance is 70
prox is 0
distance is 1995

<repeats endlessly every second>

---

Golioth Light DB stream sample

Overview

This Light DB stream application demonstrates how to connect with Golioth and periodically send data to Light DB stream. In this sample temperature measurements are sent to /temp Light DB stream path. For platforms that do not have temperature sensor a value is generated from 20 up to 30.

Requirements

• Golioth credentials
• Network connectivity

Building and Running

Configure the following Kconfig options based on your Golioth credentials:

• GOLIOTH_SYSTEM_CLIENT_PSK_ID - PSK ID of registered device
• GOLIOTH_SYSTEM_CLIENT_PSK - PSK of registered device

by adding these lines to configuration file (e.g. prj.conf):

CONFIG_GOLIOTH_SYSTEM_CLIENT_PSK_ID="my-psk-id"
CONFIG_GOLIOTH_SYSTEM_CLIENT_PSK="my-psk"

Platform specific configuration

QEMU

This application has been built and tested with QEMU x86 (qemu_x86).

On your Linux host computer, open a terminal window, locate the source code of this sample application (i.e., samples/lightdb_stream) and type:

$ west build -b qemu_x86 samples/lightdb_stream
$ west build -t run

See Networking with QEMU on how to setup networking on host and configure NAT/masquerading to access Internet.

ESP32

Configure the following Kconfig options based on your WiFi AP credentials:

• GOLIOTH_SAMPLE_WIFI_SSID - WiFi SSID
• GOLIOTH_SAMPLE_WIFI_PSK - WiFi PSK

by adding these lines to configuration file (e.g. prj.conf or board/esp32.conf):

CONFIG_GOLIOTH_SAMPLE_WIFI_SSID="my-wifi"
CONFIG_GOLIOTH_SAMPLE_WIFI_PSK="my-psk"

On your host computer open a terminal window, locate the source code of this sample application (i.e., samples/lightdb_stream) and type:

$ west build -b esp32 samples/lightdb_stream
$ west flash

See ESP32 for details on how to use ESP32 board.

nRF52840 DK + ESP32-WROOM-32

This subsection documents using nRF52840 DK running Zephyr with offloaded ESP-AT WiFi driver and ESP32-WROOM-32 module based board (such as ESP32 DevkitC rev. 4) running WiFi stack. See AT Binary Lists for links to ESP-AT binaries and details on how to flash ESP-AT image on ESP chip. Flash ESP chip with following command:

esptool.py write_flash --verify 0x0 PATH_TO_ESP_AT/factory/factory_WROOM-32.bin

Connect nRF52840 DK and ESP32-DevKitC V4 (or other ESP32-WROOM-32 based board) using wires:

nRF52840 DK	ESP32-WROOM-32
P1.01 (RX)	IO17 (TX)
P1.02 (TX)	IO16 (RX)
P1.03 (CTS)	IO14 (RTS)
P1.04 (RTS)	IO15 (CTS)
P1.05	EN
GND	GND

Configure the following Kconfig options based on your WiFi AP credentials:

• GOLIOTH_SAMPLE_WIFI_SSID - WiFi SSID
• GOLIOTH_SAMPLE_WIFI_PSK - WiFi PSK

by adding these lines to configuration file (e.g. prj.conf or board/nrf52840dk_nrf52840.conf):

CONFIG_GOLIOTH_SAMPLE_WIFI_SSID="my-wifi"
CONFIG_GOLIOTH_SAMPLE_WIFI_PSK="my-psk"

On your host computer open a terminal window, locate the source code of this sample application (i.e., samples/lightdb_stream) and type:

$ west build -b nrf52840dk_nrf52840 samples/lightdb_stream
$ west flash

nRF9160 DK

On your host computer open a terminal window, locate the source code of this sample application (i.e., samples/ligthdb_stream) and type:

$ west build -b nrf9160dk_nrf9160_ns samples/lightdb_stream
$ west flash

Sample output

This is the output from the serial console:

[00:00:00.000,000] <inf> golioth_system: Initializing
[00:00:00.000,000] <inf> net_config: Initializing network
[00:00:00.000,000] <inf> net_config: IPv4 address: 192.0.2.1
[00:00:00.000,000] <dbg> golioth_lightdb_stream.main: Start Light DB stream sample
[00:00:00.000,000] <dbg> golioth_lightdb_stream.main: Sending temperature 20.000000
[00:00:00.000,000] <inf> golioth_system: Starting connect
[00:00:00.010,000] <inf> golioth_system: Client connected!
[00:00:05.010,000] <dbg> golioth_lightdb_stream.main: Sending temperature 20.500000
[00:00:10.040,000] <dbg> golioth_lightdb_stream.main: Sending temperature 21.000000
[00:00:15.050,000] <dbg> golioth_lightdb_stream.main: Sending temperature 21.500000
[00:00:20.060,000] <dbg> golioth_lightdb_stream.main: Sending temperature 22.000000
[00:00:25.070,000] <dbg> golioth_lightdb_stream.main: Sending temperature 22.500000
[00:00:30.080,000] <dbg> golioth_lightdb_stream.main: Sending temperature 23.000000
[00:00:35.090,000] <dbg> golioth_lightdb_stream.main: Sending temperature 23.500000
[00:00:40.100,000] <dbg> golioth_lightdb_stream.main: Sending temperature 24.000000
[00:00:45.110,000] <dbg> golioth_lightdb_stream.main: Sending temperature 24.500000
[00:00:50.120,000] <dbg> golioth_lightdb_stream.main: Sending temperature 25.000000
[00:00:55.130,000] <dbg> golioth_lightdb_stream.main: Sending temperature 25.500000
[00:01:00.140,000] <dbg> golioth_lightdb_stream.main: Sending temperature 26.000000

Monitor temperature value over time

Device sends temperature measurements every 5s and updates /temp resource in Light DB stream. Current value can be fetched using following command:

$ goliothctl stream get <device-id> /temp
26

Historical data can be queried using following command:

$ goliothctl stream query --interval 5m --field time --field temp | jq ''
[
  {
    "temp": 26,
    "time": "2021-06-08 12:17:01.158 +0000 UTC"
  },
  {
    "temp": 25.5,
    "time": "2021-06-08 12:16:56.146 +0000 UTC"
  },
  {
    "temp": 25,
    "time": "2021-06-08 12:16:51.138 +0000 UTC"
  },
  {
    "temp": 24.5,
    "time": "2021-06-08 12:16:46.126 +0000 UTC"
  },
  {
    "temp": 24,
    "time": "2021-06-08 12:16:41.114 +0000 UTC"
  },
  {
    "temp": 23.5,
    "time": "2021-06-08 12:16:36.108 +0000 UTC"
  },
  {
    "temp": 23,
    "time": "2021-06-08 12:16:31.098 +0000 UTC"
  },
  {
    "temp": 22.5,
    "time": "2021-06-08 12:16:26.088 +0000 UTC"
  },
  {
    "temp": 22,
    "time": "2021-06-08 12:16:21.078 +0000 UTC"
  },
  {
    "temp": 21.5,
    "time": "2021-06-08 12:16:16.068 +0000 UTC"
  },
  {
    "temp": 21,
    "time": "2021-06-08 12:16:11.054 +0000 UTC"
  },
  {
    "temp": 20.5,
    "time": "2021-06-08 12:16:06.049 +0000 UTC"
  }
]