M5Stack AtomU User manual

AtomU
2021

CONTENTS
1. OUTLINE ............................................................................................................................. 3
1.1. ESP32 PICO ................................................................................................................................ 3
2. SPECIFICATIONS ............................................................................................................. 5
3. QUICK START.................................................................................................................... 6
3.1. ARDUINO IDE ............................................................................................................................ 6
3.2. BLUETOOTH SERIAL....................................................................................................................... 6
3.3. WIFI SCANNING ............................................................................................................................ 8

1.OUTLINE
AtomU is a very small and flexible IoT speech recognition development board,
using Espressif's `ESP32` main control chip, equipped with two low-power `Xtensa®
32-bit LX6` microprocessors, main frequency Up to `240MHz`. It has the characteristics
of compact size, strong performance and low power consumption. Integrated USB-A
interface, plug and play, easy to upload, download and debug the program. Integrated
`Wi-Fi` and `Bluetooth` modules, with built-in digital microphone SPM1423 (I2S), can
achieve clear audio recording, suitable for various IoT human-computer interaction,
voice input recognition scenarios (STT)
1.1.ESP32 PICO
•The ESP32-PICO-D4 is a System-in-Package (SiP) module that is based on ESP32, providing
complete Wi-Fi and Bluetooth functionalities. The module has a size as small as (7.000±0.100)
mm × (7.000±0.100) mm × (0.940±0.100) mm, thus requiring minimal PCB area. The module
integrates a 4-MB SPI flash. At the core of this module is the ESP32 chip*, which is a single 2.4
GHz Wi-Fi and Bluetooth combo chip designed with TSMC’s 40 nm ultra-low power

technology. ESP32-PICO-D4 integrates all peripheral components seamlessly, including a
crystal oscillator, flash, filter capacitors and RF matching links in one single package. Given
that no other peripheral components are involved, module welding and testing is not required
either. As such, ESP32-PICO-D4 reduces the complexity of supply chain and improves control
efficiency. With its ultra-small size, robust performance and low-energy consumption, ESP32-
PICO-D4 is well suited for any space-limited or battery-operated applications, such as
wearable electronics, medical equipment, sensors and other IoT products.

2. SPECIFICATIONS
Resources
Parameter
ESP32-PICO-D4
240MHz dual core, 600 DMIPS, 520KB SRAM, 2.4GHz
Wi-Fi, dual mode Bluetooth
Flash
4MB
Input voltage
5V @ 500mA
button
Programmable buttons x 1
Programmable
RGB LED
SK6812 x 1
Antenna
2.4GHz 3D Antenna
Operating
temperature
32°F to 104°F ( 0°C to 40°C )

3.QUICK START
3.1.ARDUINO IDE
Visit Arduino's official website(https://www.arduino.cc/en/Main/Software),Select the installation
package for your own operating system to download.
>1.Open up Arduino IDE, navigate to `File`->`Peferences`->`Settings`
>2.Copy the following M5Stack Boards Manager url to `Additional Boards Manager URLs:`
https://raw.githubusercontent.com/espressif/arduino-esp32/gh-
pages/package_esp32_dev_index.json
>3.Navigate to `Tools`->`Board:`->`Boards Manager...`
>4.Search `ESP32` in the pop-up window, find it and click `Install`
>5.select `Tools`->`Board:`->`ESP32-Arduino-ESP32 DEV Module
>6Please install FTDI driver before use: https://docs.m5stack.com/en/download
3.2.BLUETOOTH SERIAL
Open the Arduino IDE and open the example program
`File`->`Examples`->`BluetoothSerial`->`SerialToSerialBT`. Connect the device to the computer
and select the corresponding port to burn. After completion, the device will automatically run
Bluetooth, and the device name is `ESP32test`. At this time, use the Bluetooth serial port sending
tool on the PC to realize the transparent transmission of Bluetooth serial data.

#include "BluetoothSerial.h"
#if !defined(CONFIG_BT_ENABLED)|| !defined(CONFIG_BLUEDROID_ENABLED)
#error Bluetooth is not enabled! Please run `make menuconfig` to and en
able it
#endif
BluetoothSerial SerialBT;
void setup() {
Serial.begin(115200);

SerialBT.begin("ESP32test"); //Bluetooth device name
Serial.println("The device started, now you can pair it with bluetoot
h!");
}
void loop() {
if (Serial.available()) {
SerialBT.write(Serial.read());
}
if (SerialBT.available()) {
Serial.write(SerialBT.read());
}
delay(20);
}
3.3.WIFI SCANNING
Open the Arduino IDE and open the example program `File`->`Examples`->`WiFi`->`WiFiScan`.
Connect the device to the computer and select the corresponding port to burn. After
completion, the device will automatically run the WiFi scan, and the current WiFi scan result can
be obtained through the serial port monitor that comes with the Arduino.

#include "WiFi.h"
void setup()
{
Serial.begin(115200);
// Set WiFi to station mode and disconnect from an AP if it was pre
viously connected
WiFi.mode(WIFI_STA);
WiFi.disconnect();
delay(100);
Serial.println("Setup done");
}
void loop()
{
Serial.println("scan start");
// WiFi.scanNetworks will return the number of networks found
int n =WiFi.scanNetworks();
Serial.println("scan done");
if (n == 0){
Serial.println("no networks found");
}else {
Serial.print(n);
Serial.println(" networks found");
for (int i =0;i <n;++i){
// Print SSID and RSSI for each network found
Serial.print(i +1);
Serial.print(": ");
Serial.print(WiFi.SSID(i));
Serial.print(" (");
Serial.print(WiFi.RSSI(i));
Serial.print(")");
Serial.println((WiFi.encryptionType(i)== WIFI_AUTH_OPEN)?"
":"*");
delay(10);
}
}
Serial.println("");
// Wait a bit before scanning again
delay(5000);
}

Federal Communications Commission (FCC) Statement
You are cautioned that changes or modifications not expressly
approved by the part responsible for compliance could void the
user’s authority to operate the equipment.
This equipment has been tested and found to comply with the
limits for a Class B digital device, pursuant to part 15 of the FCC
rules. These limits are designed to provide reasonable protection
against harmful interference in a residential installation. This
equipment generates, uses and can radiate radio frequency
energy and, if not installed and used in accordance with the
instructions, may cause harmful interference to radio
communications. However, there is no guarantee that interference
will not occur in a particular installation. If this equipment does
cause harmful interference to radio or television reception, which
can be determined by turning the equipment off and on, the user
is encouraged to try to correct the interference by one or more of
the following measures:
-Reorient or relocate the receiving antenna.
-Increase the separation between the equipment and receiver.
-Connect the equipment into an outlet on a circuit different from
that to which the receiver is connected.
-Consult the dealer or an experienced radio/TV technician for
help.
This device complies with Part 15 of the FCC Rules. Operation is
subject to the following two conditions:
1) this device may not cause harmful interference, and
2) this device must accept any interference received, including
interference that may cause undesired operation of the device.
FCC RF Radiation Exposure Statement:
The product comply with the FCC portable RF exposure limit set
forth for an uncontrolled environment and are safe for intended
operation as described in this manual. The further RF exposure
reduction can be achieved if the product can be kept as far as
possible from the user body.