Detailed information on my site

For LoRa E32, LoRa E22 and LoRa E220

I start using STM32 microcontrollers, and I find they a superior quality. But I need some prototyping board to do my work faster.

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

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:

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 with PA0 (or WAKE pin) and PA1;

M0 you can select B0 and B1;

M1 you can select B2 and B10.

Here is the PCB description to better understand.

Configuration

Here is the standard configuration for the relative library

HardwareSerial Serial2(USART2);  // PA3 (RX) PA2 (TX) ?LoRa_E32 e32ttl(&Serial2, PA0, PB0, PB10); // Serial2 AUX M0 M1

Example with Arduino EByte LoRa E220 library

/* * LoRa E220 * Get configuration. * You must uncommend the correct constructor. * * by Renzo Mischianti <https://www.mischianti.org> * * https://www.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("----------------------------------------"); }