Using XIAO ESP32C3 Part 1 (Battery, Bluetooth)

Introduction

 The previous article was about my exhibit at Maker Faire Kyoto 2023. This time I will talk about the microcontroller I used for our exhibit, the XIAO ESP32C3.
 At Maker, I operated it via wireless communication with my iPhone.

 I used a LiPo battery for the first time to make it smaller. It's a bit scary to handle…

▼I exhibited like this.

▼Previous article

Maker Faire Kyoto 2023に行ってきました!

はじめに  4月29、30日には「Maker Faire Kyoto 2023」がありました。世界的な展示会です。今回はそのMakerにはじめて行ってきましたというお話です。  私は知り合いの…

About XIAO ESP32C3

 An overview has been given in a previous article; XIAO ESP32C3 is one of the smallest microcontrollers in the ESP family and can use WiFi and Bluetooth.
 ESP32C3 supports BLE among Bluetooth standards. My iPhone 8 also seems to support BLE.

▼The official Getting Started page is here.

Getting Started with Seeed Studio XIAO ESP32C3 | Seeed Studio Wiki

▼Purchase page is here.

Seeed Studio XIAO ESP32C3 — スイッチサイエンス (switch-science.com)

Seeed Studio XIAO ESP32C3: マイコン関連 秋月電子通商-電子部品・ネット通販 (akizukidenshi.com)

▼Previous article

ちょっと調べもの:ESP32C3とBluetoothの規格

はじめに  このホームページでは、度々ESP32とPS4のコントローラ(DUALSHOCK4)をBluetoothで接続する方法についてまとめています。今回の記事は、ESP32C3でもPS4のコン…

Battery Power Supply and Charging

 It is written in the "Battery Usage" section of Getting Started.

 There is a battery terminal on the back of the ESP32C3, which allows you to power the microcontroller with a 3.7V LiPo battery. To charge the battery, you can use the ESP32C3's own battery charger function.

 You were warned not to short + and - when soldering, but it seems difficult, so it is better to attach connectors that can be removed.

▼This is the picture of the soldered device. I am worried about the short-circuiting in some way.

▼If you want to buy a charger for LiPo batteries, I recommend Adafruit's module, which is also available for Type-C.

Checking Battery Voltage

 I read in the "Check the battery voltage" section of Getting Started that you can read the battery voltage on the pin.

▼Where it was discussed.

 Battery voltage monitor and AD conversion for XIAO_ESP32C - Products & Technology / XIAO - Seeed Forum (seeedstudio.com)

 I didn't have a 220k ohm resistor so I substituted a 2k ohm resistor. There was a difference of about 0.1V between the voltage I measured with the tester and the voltage I read on the pin.

 I am able to measure the voltage on the A0 pin. I can check the status with the full color LED on the external board.

▼It looks like this when mounted on the board. Because the microcontroller is small, the board is also much smaller.

Communication with iPhone via Bluetooth

▼I refer to this page

 https://wiki.seeedstudio.com/XIAO_ESP32C3_Bluetooth_Usage/

 It showed me how to communicate with my phone using an app called "Light Blue." I am using an iPhone 8, so I used the Apple version of the app to communicate.

How to use Light Blue

※ID is painted in.

▼Light Blue screen. Pressing the ">" button will show you more details.

▼You can send data from Write new value. You can change the data format by selecting Hex, which is written in the upper right corner.

▼Screen of selection. In this case, data will be sent in UTF-8.

▼Now I can send the data. You can use Serial.read in the Arduino IDE to get the value and branch the program.

How it works

▼Here is a video of the operation from an iPhone. I should have used a motor with a higher rotation speed. It takes a lot of time to input data.

Sample Programs

▼Still a simple program that can only check voltage and control full color LED dimming via Bluetooth.

▼Here is the program including motor control. It is still under adjustment and is messy.

Finally

 I used Light Blue to control it this time, but there are other apps that support Bluetooth, and there are other ways to control it via WiFi. I would like to use the Node-RED MCU dashboard to operate it.

 The ESP32C3 is really useful, I can use WiFi and Bluetooth, and it's my favorite microcontroller because it's kind of minimal. I am concerned that it gets pretty hot during operation, but so far it has been working fine.


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