This article shows how to use DeviceScript to program a microcontroller (ESP32-C3), a temperature/humidity sensor (BME680) and a LCD character screen to build a tiny weather dashboard. This project does not require soldering or embedded skills.
In a previous article, we looked at using an OLED screen to display temperature readings using DeviceScript.
DeviceScript
DeviceScript brings JavaScript/TypeScript to tiny IoT devices such as the ESP32. DeviceScript provides a user friendly editing/debugging experience in Visual Studio Code.
You can follow along this tutorial without any hardware and use the simulators provided by DeviceScript. Otherwise, the parts needed are
Seeed Studio Xiao + Grove shield
The Xiao ESP32-C3 is a low-cost compact microcontroller board running the Espressif ESP32-C3.
The Grove shield for Xiao is a convenient base for the Xiao that provides an easy access to OLED screens, Grove connectors and battery charging.
DeviceScript provides a shield drivers that configures the pins and the OLED display for this hardware combo.
import { XiaoGroveShield} from "@devicescript/drivers" const shield = new XiaoGroveShield() LCD screen as character screen
The Grove LCD screen supports 16 columns and rows of characters; it provides an I2C interface that dramatically reduces the complexity of connecting this kind of devices (just plug the grove connector and go). The driver is written in TypeScript/DeviceScript.
The sceen is modelled as a character screen. Using services allows DeviceScript to provide simulation and device twin capabilities to your coding experience.
import { XiaoGroveShield, startGroveRGBLCD16x2, } from "@devicescript/drivers" const shield = new XiaoGroveShield() const screen = await startGroveRGBLCD16x2() await screen.message.write('starting...') BME680
The BME680 is a high-precision temperature/humidity/gas sensor that can be conveniently connected through one of the grove connector.
The sensor is exposed as 3 services, temperature, humidity, air quality, that can be used to poll the sensor data and display it on the screen.
import { startBME680, } from "@devicescript/drivers" ... const { temperature, humidity } = await startBME680({ address: 0x76 }) const temp = await temperature.reading.read() const humi = await humidity.reading.read() await screen.message.write(`t ${temp}\nh ${humi}`) Simulation
You try this code without hardware. DeviceScript will spin up simulators for the Xiao, the sensors and screens.
Value dashboard
Since display sensor values is a common task, DeviceScript provides a helper ValueDashboard to render a list of sensor data.
The value dashboard
import { ValueDashboard } from "@devicescript/runtime" ... const dashboard = new ValueDashboard(screen, { temperature: { digits: 1, unit: "C" }, humi: { digits: 0, unit: "%" }, }) setInterval(async () => { dashboard.values.temperature = temperature.reading.read() dashboard.values.humi = humidity.reading.read() await dashboard.show() }, 1000) All together
The final sample is a tiny weather display that shows the temperature/humidity reported by the BME680 sensor.
import { startGroveRGBLCD16x2, startBME680, XiaoGroveShield, } from "@devicescript/drivers" import { ValueDashboard } from "@devicescript/runtime" const shield = new XiaoGroveShield() const { temperature, humidity } = await startBME680({ address: 0x76, }) const screen = await startGroveRGBLCD16x2() const dashboard = new ValueDashboard(screen, { temp: { digits: 1, unit: "C" }, humi: { digits: 0, unit: "%" }, }) setInterval(async () => { dashboard.values.temp = await temperature.reading.read() dashboard.values.humi = await humidity.reading.read() await dashboard.show() }, 1000) 
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