Unleashing IoT Potential: Integrating STM32F4 Black-Pill with EByte LoRa E32, E22, and E220 Shield
In the rapidly expanding world of the Internet of Things (IoT), long-range and low-power communication technologies are becoming increasingly crucial. One such technology, known as LoRa (Long Range), has emerged as a leading solution, thanks to its ability to facilitate extensive, low-energy communication between IoT devices.
The STM32F4 Black-Pill, a powerful and versatile microcontroller, offers promising potential for IoT applications when integrated with LoRa modules like EByte’s E32, E22, and E220. In this article, we’ll examine the Shield I use for rapid prototyping that supports all the LoRa modules described.
So here is a prototype board to develop the LoRa application. As usual, I use EByte modules, and this board is fully compatible with E32, E22, and E220.
STM32F4 black-pill pinout
As you can see in the pinout diagram you can find more than one Serial interface. In this board, I add jumpers to select Serial1 (Tx -> PA9, Rx->PA10
) and Serial2 (Tx -> PA2, and Rx->PA3
) interface.
The selectable pins are also AUX, M0 and M1.
Here my selection of STM32 STM32F103C8T6 STM32F401 STM32F411 ST-Link v2 ST-Link v2 official
For AUX
I put PA0
(or WAKE pin) and PA1
, for M0
you can select B0
and B1
, for M1
the B2
and B10
.
You can also put M0 and M1 in fixed mode and select the static status in the DIP-switch.
PCB
You can order the PCB from PCBWay for few dollars PCBWay
As usual, I create a PCB that can be milled, so when I send It to the factory for production, I’m sure that it works correctly.
The design is quite simple, you can check the connection in the PCB schema:
The standard configuration is:
HardwareSerial Serial2(USART2); // PA3 (RX) PA2 (TX)
LoRa_E32 e32ttl(&Serial2, PA0, PB0, PB10); // Serial2 AUX M0 M1
But, as already described, you can select with the jumpers other configuration:
- Serial1 (
Tx->PA9, Rx->PA10
) or Serial2 (Tx->PA2, Rx->PA3
); AUX
withPA0
(or WAKE pin) andPA1
;M0
you can selectB0
andB1
;M1
you can selectB2
andB10
.
Here is the PCB description to better understand.
Shopping List
EByte LoRa E32 AliExpress (433MHz 5Km) - AliExpress (433MHz 8Km) - AliExpress (433MHz 16Km) - AliExpress (868MHz 915MHz 5.5Km) - AliExpress (868MHz 915MHz 8Km)
EByte LoRa E22 AliExpress (433MHz 5.5Km) - AliExpress (433MHz 10Km) - AliExpress (868MHz 915Mhz 5.5Km) - AliExpress (868MHz 915Mhz 10Km)
EByte LoRa E220 E220-400T22D 433MHz 5Km - E220-400T30D 433MHz 10Km - E220-900T22D 868MHz 915MHz 5Km - E220-900T30D 868MHz 915MHz 10Km
Amount Part Type Properties 1 Lora Exx variant 1; voltage 3-5V; type Basic 1 DIP SWITCH channels 1; package dipswitch-02 2 Generic male header – 3 pins pins 3; pin spacing 0.1in (2.54mm); hole size 1.0mm,0.508mm; form ♂ (male); package THT; row single 3 4.7kΩ Resistor bands 4; tolerance ±5%; pin spacing 400 mil; package THT; resistance 4.7kΩ 3 2kΩ Resistor bands 4; tolerance ±5%; pin spacing 400 mil; package THT; resistance 2kΩ Generic female header Pin spacing 0.1in (2.54mm); Generic male/female header Pin spacing 0.1in (2.54mm);
Configuration and test (Arduino & MicroPython)
I’m going to show a simple sketch to get the configuration of an EByte LoRa E220. First of all, remember to set the correct constructor with the correct selection of the pin.
/*
* LoRa E220
* Get configuration.
* You must uncommend the correct constructor.
*
* by Renzo Mischianti <https://mischianti.org>
*
* https://mischianti.org
*
* E220 ----- WeMos D1 mini ----- esp32 ----- Arduino Nano 33 IoT ----- Arduino MKR ----- Raspberry Pi Pico ----- stm32 ----- ArduinoUNO
* M0 ----- D7 (or 3.3v) ----- 19 (or 3.3v) ----- 4 (or 3.3v) ----- 2 (or 3.3v) ----- 10 (or 3.3v) ----- PB0 (or 3.3v) ----- 7 Volt div (or 3.3v)
* M1 ----- D6 (or 3.3v) ----- 21 (or 3.3v) ----- 6 (or 3.3v) ----- 4 (or 3.3v) ----- 11 (or 3.3v) ----- PB10 (or 3.3v) ----- 6 Volt div (or 3.3v)
* TX ----- D3 (PullUP) ----- TX2 (PullUP) ----- TX1 (PullUP) ----- 14 (PullUP) ----- 8 (PullUP) ----- PA2 TX2 (PullUP) ----- 4 (PullUP)
* RX ----- D4 (PullUP) ----- RX2 (PullUP) ----- RX1 (PullUP) ----- 13 (PullUP) ----- 9 (PullUP) ----- PA3 RX2 (PullUP) ----- 5 Volt div (PullUP)
* AUX ----- D5 (PullUP) ----- 18 (PullUP) ----- 2 (PullUP) ----- 0 (PullUP) ----- 2 (PullUP) ----- PA0 (PullUP) ----- 3 (PullUP)
* VCC ----- 3.3v/5v ----- 3.3v/5v ----- 3.3v/5v ----- 3.3v/5v ----- 3.3v/5v ----- 3.3v/5v ----- 3.3v/5v
* GND ----- GND ----- GND ----- GND ----- GND ----- GND ----- GND ----- GND
*
*/
#include "Arduino.h"
#include "LoRa_E220.h"
// ---------- esp8266 pins --------------
//LoRa_E220 e220ttl(RX, TX, AUX, M0, M1); // Arduino RX <-- e220 TX, Arduino TX --> e220 RX
//LoRa_E220 e220ttl(D3, D4, D5, D7, D6); // Arduino RX <-- e220 TX, Arduino TX --> e220 RX AUX M0 M1
//LoRa_E220 e220ttl(D2, D3); // Config without connect AUX and M0 M1
//#include <SoftwareSerial.h>
//SoftwareSerial mySerial(D2, D3); // Arduino RX <-- e220 TX, Arduino TX --> e220 RX
//LoRa_E220 e220ttl(&mySerial, D5, D7, D6); // AUX M0 M1
// -------------------------------------
// ---------- Arduino pins --------------
//LoRa_E220 e220ttl(4, 5, 3, 7, 6); // Arduino RX <-- e220 TX, Arduino TX --> e220 RX AUX M0 M1
//LoRa_E220 e220ttl(4, 5); // Config without connect AUX and M0 M1
//#include <SoftwareSerial.h>
//SoftwareSerial mySerial(4, 5); // Arduino RX <-- e220 TX, Arduino TX --> e220 RX
//LoRa_E220 e220ttl(&mySerial, 3, 7, 6); // AUX M0 M1
// -------------------------------------
// ------------- Arduino Nano 33 IoT -------------
// LoRa_E220 e220ttl(&Serial1, 2, 4, 6); // RX AUX M0 M1
// -------------------------------------------------
// ------------- Arduino MKR WiFi 1010 -------------
// LoRa_E220 e220ttl(&Serial1, 0, 2, 4); // RX AUX M0 M1
// -------------------------------------------------
// ---------- esp32 pins --------------
// LoRa_E220 e220ttl(&Serial2, 15, 21, 19); // RX AUX M0 M1
//LoRa_E220 e220ttl(&Serial2, 22, 4, 18, 21, 19, UART_BPS_RATE_9600); // esp32 RX <-- e220 TX, esp32 TX --> e220 RX AUX M0 M1
// -------------------------------------
// ---------- Raspberry PI Pico pins --------------
// LoRa_E220 e220ttl(&Serial2, 2, 10, 11); // RX AUX M0 M1
// -------------------------------------
// ---------------- STM32 --------------------
HardwareSerial Serial2(USART2); // PA3 (RX) PA2 (TX)
LoRa_E220 e220ttl(&Serial2, PA0, PB0, PB10); // RX AUX M0 M1
// -------------------------------------------------
void printParameters(struct Configuration configuration);
void printModuleInformation(struct ModuleInformation moduleInformation);
void setup() {
Serial.begin(9600);
while(!Serial){};
delay(500);
Serial.println();
// Startup all pins and UART
e220ttl.begin();
ResponseStructContainer c;
c = e220ttl.getConfiguration();
// It's important get configuration pointer before all other operation
Configuration configuration = *(Configuration*) c.data;
Serial.println(c.status.getResponseDescription());
Serial.println(c.status.code);
printParameters(configuration);
ResponseStructContainer cMi;
cMi = e220ttl.getModuleInformation();
// It's important get information pointer before all other operation
ModuleInformation mi = *(ModuleInformation*)cMi.data;
Serial.println(cMi.status.getResponseDescription());
Serial.println(cMi.status.code);
printModuleInformation(mi);
}
void loop() {
}
void printParameters(struct Configuration configuration) {
Serial.println("----------------------------------------");
Serial.print(F("HEAD : ")); Serial.print(configuration.COMMAND, HEX);Serial.print(" ");Serial.print(configuration.STARTING_ADDRESS, HEX);Serial.print(" ");Serial.println(configuration.LENGHT, HEX);
Serial.println(F(" "));
Serial.print(F("AddH : ")); Serial.println(configuration.ADDH, HEX);
Serial.print(F("AddL : ")); Serial.println(configuration.ADDL, HEX);
Serial.println(F(" "));
Serial.print(F("Chan : ")); Serial.print(configuration.CHAN, DEC); Serial.print(" -> "); Serial.println(configuration.getChannelDescription());
Serial.println(F(" "));
Serial.print(F("SpeedParityBit : ")); Serial.print(configuration.SPED.uartParity, BIN);Serial.print(" -> "); Serial.println(configuration.SPED.getUARTParityDescription());
Serial.print(F("SpeedUARTDatte : ")); Serial.print(configuration.SPED.uartBaudRate, BIN);Serial.print(" -> "); Serial.println(configuration.SPED.getUARTBaudRateDescription());
Serial.print(F("SpeedAirDataRate : ")); Serial.print(configuration.SPED.airDataRate, BIN);Serial.print(" -> "); Serial.println(configuration.SPED.getAirDataRateDescription());
Serial.println(F(" "));
Serial.print(F("OptionSubPacketSett: ")); Serial.print(configuration.OPTION.subPacketSetting, BIN);Serial.print(" -> "); Serial.println(configuration.OPTION.getSubPacketSetting());
Serial.print(F("OptionTranPower : ")); Serial.print(configuration.OPTION.transmissionPower, BIN);Serial.print(" -> "); Serial.println(configuration.OPTION.getTransmissionPowerDescription());
Serial.print(F("OptionRSSIAmbientNo: ")); Serial.print(configuration.OPTION.RSSIAmbientNoise, BIN);Serial.print(" -> "); Serial.println(configuration.OPTION.getRSSIAmbientNoiseEnable());
Serial.println(F(" "));
Serial.print(F("TransModeWORPeriod : ")); Serial.print(configuration.TRANSMISSION_MODE.WORPeriod, BIN);Serial.print(" -> "); Serial.println(configuration.TRANSMISSION_MODE.getWORPeriodByParamsDescription());
Serial.print(F("TransModeEnableLBT : ")); Serial.print(configuration.TRANSMISSION_MODE.enableLBT, BIN);Serial.print(" -> "); Serial.println(configuration.TRANSMISSION_MODE.getLBTEnableByteDescription());
Serial.print(F("TransModeEnableRSSI: ")); Serial.print(configuration.TRANSMISSION_MODE.enableRSSI, BIN);Serial.print(" -> "); Serial.println(configuration.TRANSMISSION_MODE.getRSSIEnableByteDescription());
Serial.print(F("TransModeFixedTrans: ")); Serial.print(configuration.TRANSMISSION_MODE.fixedTransmission, BIN);Serial.print(" -> "); Serial.println(configuration.TRANSMISSION_MODE.getFixedTransmissionDescription());
Serial.println("----------------------------------------");
}
void printModuleInformation(struct ModuleInformation moduleInformation) {
Serial.println("----------------------------------------");
Serial.print(F("HEAD: ")); Serial.print(moduleInformation.COMMAND, HEX);Serial.print(" ");Serial.print(moduleInformation.STARTING_ADDRESS, HEX);Serial.print(" ");Serial.println(moduleInformation.LENGHT, DEC);
Serial.print(F("Model no.: ")); Serial.println(moduleInformation.model, HEX);
Serial.print(F("Version : ")); Serial.println(moduleInformation.version, HEX);
Serial.print(F("Features : ")); Serial.println(moduleInformation.features, HEX);
Serial.println("----------------------------------------");
}
And here is the Serial output.
Success
1
----------------------------------------
HEAD : C1 0 8
AddH : 0
AddL : 3
Chan : 23 -> 433MHz
SpeedParityBit : 0 -> 8N1 (Default)
SpeedUARTDatte : 11 -> 9600bps (default)
SpeedAirDataRate : 10 -> 2.4kbps (default)
OptionSubPacketSett: 0 -> 200bytes (default)
OptionTranPower : 0 -> 22dBm (Default)
OptionRSSIAmbientNo: 0 -> Disabled (default)
TransModeWORPeriod : 11 -> 2000ms (default)
TransModeEnableLBT : 0 -> Disabled (default)
TransModeEnableRSSI: 0 -> Disabled (default)
TransModeFixedTrans: 1 -> Fixed transmission (first three bytes can be used as high/low address and channel)
----------------------------------------
Success
1
----------------------------------------
HEAD: C1 8 3
Model no.: 13
Version : A
Features : 16
----------------------------------------
Now for MicroPython, another simple sketch
# Author: Renzo Mischianti
# Website: www.mischianti.org
#
# Description:
# This script initializes the E220 LoRa module with MicroPython,
# retrieves the current configuration, and prints it to the console.
# The code demonstrates how to use the LoRaE32 library to interact with the module and read its configuration.
#
from machine import UART
from lora_e220 import LoRaE220, print_configuration
from lora_e220_operation_constant import ResponseStatusCode
# uart2 = UART(2)
# lora = LoRaE220('400T22D', uart2, aux_pin=15, m0_pin=21, m1_pin=19)
# STM32F411CEU6 Shield
uart2 = UART(2)
lora = LoRaE220('400T22D', uart2, aux_pin='PA0', m0_pin='PB0', m1_pin='PB2')
code = lora.begin()
print("Initialization: {}", ResponseStatusCode.get_description(code))
code, configuration = lora.get_configuration()
print("Retrieve configuration: {}", ResponseStatusCode.get_description(code))
print_configuration(configuration)
Thanks
- STM32F1 Blue-Pill: pinout, specs, and Arduino IDE configuration (STM32duino and STMicroelectronics)
- STM32: program (STM32F1) via USB with STM32duino bootloader
- STM32: programming (STM32F1 STM32F4) via USB with HID boot-loader
- STM32F4 Black-Pill: pinout, specs, and Arduino IDE configuration
- STM32: ethernet w5500 with plain HTTP and SSL (HTTPS)
- STM32: ethernet enc28j60 with plain HTTP and SSL (HTTPS)
- STM32: WiFiNINA with ESP32 WiFi Co-Processor
- How to use SD card with stm32 and SdFat library
- \STM32: SPI flash memory FAT FS
- STM32: internal RTC, clock, and battery backup (VBAT)
- STM32 LoRa
- STM32 Power saving
- STM32F1 Blue-Pill clock and frequency management
- STM32F4 Black-Pill clock and frequency management
- Intro and Arduino vs STM framework
- Library LowPower, wiring, and Idle (STM Sleep) mode
- Sleep, deep sleep, shutdown, and power consumption
- Wake up from RTC alarm and Serial
- Wake up from the external source
- Backup domain intro and variable preservation across reset
- RTC backup register and SRAM preservation
- STM32 send emails with attachments and SSL (like Gmail): w5500, enc28j60, SD, and SPI Fash
- FTP server on STM32 with w5500, enc28j60, SD Card, and SPI Flash
- Connecting the EByte E70 to STM32 (black/blue pill) devices and a simple sketch example