A few weeks ago I switched from the Arduino IDE to PlatformIO. Since then developing of MySensors nodes becomes as convenient as it is developing Java or NodeJS applications. Then I tried to build a base library to share common functionality across my different projects. To archive this I've build a PlatformIO library project and added MySensors as dependency, since I want to add or wrap existing MySensors functionality. When I try to build one of my depending projects, LDF resolves the dependency tree as following:

Library Dependency Graph
|-- <BaseLibrary>
|   |-- <MySensors> v2.1.0
|   |   |-- <SPI> v1.0
|   |   |-- <Wire> v1.0
|   |   |-- <EEPROM> v1.0
|-- <SPI> v1.0
|-- <MySensors> v2.1.0
|   |-- <SPI> v1.0
|   |-- <Wire> v1.0
|   |-- <EEPROM> v1.0
|-- <EEPROM> v1.0
|-- <ESP8266WiFi> v1.0

But when I add #include <MySensors.h> to my BaseLibrary.cpp and build the depending project, the linker shows for each MySensors method the error ... multiple definition .... From my understandung the following precompiler statement

#ifndef MySensors_h
#define MySensors_h

should avoid that this happens. Does anyone know how to build a multi project library with a MySensors dependency? Is this possible with the current MySensors design?

I've ordered three of them and tried to get them working. But when I reproduce your configuration, the debug messages show me that it's not possible to establish a connection to the RF24 module.

Here is my configuration

// Enable debug prints to serial monitor
#define MY_DEBUG
#define MY_DEBUG_VERBOSE_RF24

// Enable and select radio type attached
#define MY_RADIO_RF24

// PINS for the RF24 Communication
#define MY_RF24_CE_PIN 10 
#define MY_RF24_CS_PIN 9

// Add some wait time until network is ready on node startup
#define MY_TRANSPORT_WAIT_READY_MS 1000

// Enable AES encryption
#define MY_RF24_ENABLE_ENCRYPTION

// Enable message signing
#define MY_SIGNING_SOFT
// Not longer required since the CPU integrated random numger generator is used
//#define MY_SIGNING_SOFT_RANDOMSEED_PIN A0
#define MY_VERIFICATION_TIMEOUT_MS 5000
#define MY_SIGNING_REQUEST_SIGNATURES
#define MY_SIGNING_GW_REQUEST_SIGNATURES_FROM_ALL

this are the log statements:

 __  __       ____
|  \/  |_   _/ ___|  ___ _ __  ___  ___  _ __ ___
| |\/| | | | \___ \ / _ \ `_ \/ __|/ _ \| `__/ __|
| |  | | |_| |___| |  __/ | | \__ \  _  | |  \__ \
|_|  |_|\__, |____/ \___|_| |_|___/\___/|_|  |___/
        |___/                      2.3.1

16 MCO:BGN:INIT NODE,CP=RNNNAS-X,REL=255,VER=2.3.1
65 TSM:INIT
66 TSF:WUR:MS=1000
68 RF24:INIT
69 RF24:INIT:PIN,CE=10,CS=9
71 RF24:SBY
72 RF24:WBR:REG=0,VAL=14
79 RF24:WBR:REG=3,VAL=3
81 RF24:WBR:REG=4,VAL=95
83 RF24:WBR:REG=5,VAL=76
87 RF24:WBR:REG=6,VAL=37
89 RF24:WBR:REG=29,VAL=4
91 RF24:RBR:REG=29,VAL=4
93 RF24:RBR:REG=6,VAL=5
95 !RF24:INIT:SANCHK FAIL
98 !TSM:INIT:TSP FAIL
99 TSM:FAIL:CNT=1
101 TSM:FAIL:DIS
103 TSF:TDI:TSL
104 RF24:SLP
105 RF24:WBR:REG=0,VAL=12
1067 MCO:BGN:STP
1068 !TSF:SND:TNR
1070 !TSF:SND:TNR

Currently I power the whole thing just trough the connected USB device. Is it possible that RF24 doesn't get powered through USB and has to be powered externally...? I tried different configurations and none of them got the RF24 working.

A few weeks ago I switched from the Arduino IDE to PlatformIO. Since then developing of MySensors nodes becomes as convenient as it is developing Java or NodeJS applications. Then I tried to build a base library to share common functionality across my different projects. To archive this I've build a PlatformIO library project and added MySensors as dependency, since I want to add or wrap existing MySensors functionality. When I try to build one of my depending projects, LDF resolves the dependency tree as following:

Library Dependency Graph
|-- <BaseLibrary>
|   |-- <MySensors> v2.1.0
|   |   |-- <SPI> v1.0
|   |   |-- <Wire> v1.0
|   |   |-- <EEPROM> v1.0
|-- <SPI> v1.0
|-- <MySensors> v2.1.0
|   |-- <SPI> v1.0
|   |-- <Wire> v1.0
|   |-- <EEPROM> v1.0
|-- <EEPROM> v1.0
|-- <ESP8266WiFi> v1.0

But when I add #include <MySensors.h> to my BaseLibrary.cpp and build the depending project, the linker shows for each MySensors method the error ... multiple definition .... From my understandung the following precompiler statement

#ifndef MySensors_h
#define MySensors_h

should avoid that this happens. Does anyone know how to build a multi project library with a MySensors dependency? Is this possible with the current MySensors design?