M5Stack POECAM User manual

M5STACK-
POECAM
2022
V0.01

2
TABLE OF CONTENTS
1. OUTLINE ................................................................................ 3
2. SPECIFICATIONS......................................................................... 4
3．FUNCTIONAL DESCRIPTION ........................................................ 5
1.1. CPU AND MEMORY..................................................................5
1.2. STORAGE DESCRIPTION..............................................................5
1.2.1. External Flash and SRAM ..................................................5
1.3. CRYSTAL ..............................................................................5
1.4. RTC MANAGEMENT AND LOW POWER CONSUMPTION............................6
4. ELECTRICAL CHARACTERISTICS .................................................. 7
4.1. LIMIT PARAMETERS...................................................................7
4.2. WIFI RADIO FREQUENCY ............................................................7
4.3. LOW-POWER BLUETOOTH RADIO ...................................................8
4.3.1. receiver ........................................................................8
4.3.2. launcher .......................................................................8

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1.OUTLINE
M5Station is a general-purpose IoT workstation in the M5Stack development kit
series. It integrates rich interfaces and peripherals and is highly expandable. Large
space reserved inside, flexible customization, and more likely to be applicable to
various industrial acquisition and control application scenarios.

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2. SPECIFICATIONS

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3．FUNCTIONAL DESCRIPTION
This chapter describes the ESP32-D0WDQ6-V3 various modules and functions.
1.1.CPU AND MEMORY
Xtensa®single-/dual-core32-bitLX6microprocessor(s), upto600MIPS
(200MIPSforESP32-S0WD/ESP32-U4WDH, 400 MIPS for ESP32-D2WD):
⚫448 KB ROM
⚫520 KB SRAM
⚫16 KB SRAM in RTC
⚫QSPI supports multiple flash/SRAM chips
1.2.STORAGE DESCRIPTION
1.2.1.External Flash and SRAM
ESP32 support multiple external QSPI flash and static random access memory
(SRAM), having a hardware-based AES encryption to protect the user programs and
data.
⚫ESP32 access external QSPI Flash and SRAM by caching. Up to 16 MB external
Flash code space is mapped into the CPU, supports 8-bit, 16-bit and 32-bit
access, and can execute code. 
⚫Up to 8 MB external Flash and SRAM mapped to the CPU data space, support
for 8-bit, 16-bit and 32-bit access. Flash supports only read operations, SRAM
supports read and write operations. 
1.3.CRYSTAL
External 2 MHz~60 MHz crystal oscillator (40 MHz only for Wi-Fi/BT
functionality)

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1.4.RTC MANAGEMENT AND LOW POWER
CONSUMPTION
ESP32 uses advanced power management techniques may be switched between
different power saving modes. (See Table 5).
• Power saving mode
- Active Mode: RF chip is operating. Chip may receive and transmit a sounding
signal. 
- Modem-sleep mode: CPU can run, the clock may be configured. Wi-Fi /
Bluetooth baseband and RF
- Light-sleep mode: CPU suspended. RTC and memory and peripherals ULP
coprocessor operation. Any wake-up event (MAC, host, RTC timer or external
interrupt) will wake up the chip. 
- Deep-sleep mode: only the RTC memory and peripherals in a working state. Wi-
Fi and Bluetooth connectivity data stored in the RTC. ULP coprocessor can work. 
- Hibernation Mode: 8 MHz oscillator and a built-in coprocessor ULP are
disabled. RTC memory to restore the power supply is cut off. Only one RTC clock
timer located on the slow clock and some RTC GPIO at work. RTC RTC clock or
timer can wake up from the GPIO Hibernation mode.
• Deep-sleep mode 
- related sleep mode: power save mode switching between Active, Modem-sleep,
Light-sleep mode. CPU, Wi-Fi, Bluetooth, and radio preset time interval to be
awakened, to ensure connection Wi-Fi / Bluetooth. 
- Ultra Low-power sensor monitoring methods: the main system is Deep-sleep
mode, ULP coprocessor is periodically opened or closed to measure sensor data.
The sensor measures data, ULP coprocessor decide whether to wake up the main
system.
Functions in different power consumption modes: TABLE 5 

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4. ELECTRICAL CHARACTERISTICS
4.1.LIMIT PARAMETERS
Table 8: Limiting values
1. VIO to the power supply pad, Refer ESP32 Technical Specification Appendix
IO_MUX, as SD_CLK of Power supply for VDD_SDIO.
4.2.WIFI RADIO FREQUENCY
Table 9: Wi-Fi RF characteristics

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4.3.LOW-POWER BLUETOOTH RADIO
4.3.1.receiver
Table 10: Low-power Bluetooth receiver characteristics
4.3.2.launcher
Table 11: Characteristics of Low Power Bluetooth transmitter

M5STACK-
POECAM
2022
V0.01

2
TABLE OF CONTENTS
1. QUICK START .......................................................................... 3
1.1. ARDUINO IDE .....................................................................3
1.2. BLUETOOTH SERIAL .................................................................3
1.3. WIFI SCANNING.....................................................................5

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1.QUICK START
1.1.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 CH9102 driver before use esp32 downloader kit burn the
firmware:
https://shop.m5stack.com/products/esp32-downloader-kit
1.2.BLUETOOTH SERIAL

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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

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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);
}
1.3.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.

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#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);
}

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.
-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.
Any Changes or modifications not expressly approved by the party responsible
for compliance could void the user's authority to operate the equipment.
Note: 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:
This equipment complies with FCC radiation exposure limits set forth for an
uncontrolled environment.
This equipment should be installed and operated with minimum distance 20cm
etween the radiator & your body.