# ESP8266WiFi // Wemos D1 Mini // RFID reader

**URL:** <https://community.homey.app/t/esp8266wifi-wemos-d1-mini-rfid-reader/17790>\
**Category:** Questions & Help\
**Created:** [September 6, 2019, 9:45am UTC](https://community.homey.app/t/esp8266wifi-wemos-d1-mini-rfid-reader/17790 "2019-09-06T09:45:30Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![MacMillan](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/macmillan/32/13677_2.png) [@MacMillan](https://community.homey.app/u/MacMillan)\
**Post date:** [September 6, 2019, 9:45am UTC](https://community.homey.app/t/esp8266wifi-wemos-d1-mini-rfid-reader/17790/1 "2019-09-06T09:45:30Z")

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Hei,

Have any of you done this project?

> <https://github.com/athombv/homey-arduino-library/blob/3fd721be1afa2e40a22829fd9aadffd215e7bbaa/examples/Example%20projects/nfc_reader/README.md>

I’m having some issues compiling this sketch for the Wemos D1 Mini.  
Not even the example card is working:

“Error compiling for board NodeMCU 1.0 (ESP-12E Module).”  
“Error compiling for board LOLIN(WEMOS) D1 R2 & mini.”

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**Author:** ![robertklep](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/robertklep/32/160628_2.png) [@robertklep](https://community.homey.app/u/robertklep)\
**Post date:** [September 6, 2019, 10:18am UTC](https://community.homey.app/t/esp8266wifi-wemos-d1-mini-rfid-reader/17790/2 "2019-09-06T10:18:56Z")

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Seems to compile just fine for me:

 ![image](https://us1.discourse-cdn.com/flex025/uploads/athom/original/2X/2/2de54d81c9fa99c3ecbc8e6fed17e401cc0de3c0.png)

(however, I’m using PlatformIO and not the Arduino IDE)

What are the specific errors that you’re getting?

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<div class="post-metadata">

**Author:** ![MacMillan](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/macmillan/32/13677_2.png) [@MacMillan](https://community.homey.app/u/MacMillan)\
**Post date:** [September 6, 2019, 11:16am UTC](https://community.homey.app/t/esp8266wifi-wemos-d1-mini-rfid-reader/17790/3 "2019-09-06T11:16:31Z")

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Arduino: 1.8.9 (Windows 7), Board: “LOLIN(WEMOS) D1 R2 & mini, 80 MHz, Flash, Disabled, All SSL ciphers (most compatible), 4M (no SPIFFS), v2 Lower Memory, Disabled, None, Only Sketch, 921600”

Build options changed, rebuilding all  
In file included from C:\Users\ajn\Documents\Arduino\libraries\ESP8266WiFi\src/WiFiClientSecureBearSSL.h:29:0,

```
             from C:\Users\ajn\Documents\Arduino\libraries\ESP8266WiFi\src/WiFiClientSecure.h:41,

             from C:\Users\ajn\Documents\Arduino\libraries\ESP8266WiFi\src/WiFiServerSecure.h:20,

             from C:\Users\ajn\Documents\Arduino\libraries\ESP8266WiFi\src/ESP8266WiFi.h:41,

             from C:\Users\ajn\Documents\Arduino\Homey_RFID\Homey_RFID.ino:1:

```

C:\Users\ajn\Documents\Arduino\libraries\ESP8266WiFi\src/BearSSLHelpers.h:148:34: error: ‘virtual const unsigned char\* BearSSL::HashSHA256::oid()’ marked override, but does not override

```
 virtual const unsigned char *oid() override;

                              ^

```

Multiple libraries were found for “ESP8266WiFi.h”  
Used: C:\Users\ajn\Documents\Arduino\libraries\ESP8266WiFi  
Not used: C:\Users\ajn\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\2.5.2\libraries\ESP8266WiFi  
exit status 1  
Error compiling for board LOLIN(WEMOS) D1 R2 & mini.

This report would have more information with  
“Show verbose output during compilation”  
option enabled in File -\> Preferences.

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<div class="post-metadata">

**Author:** ![robertklep](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/robertklep/32/160628_2.png) [@robertklep](https://community.homey.app/u/robertklep)\
**Post date:** [September 6, 2019, 11:29am UTC](https://community.homey.app/t/esp8266wifi-wemos-d1-mini-rfid-reader/17790/4 "2019-09-06T11:29:07Z")

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> [@MacMillan](#):
>
> Multiple libraries were found for “ESP8266WiFi.h”  
> Used: C:\Users\ajn\Documents\Arduino\libraries\ESP8266WiFi  
> Not used: C:\Users\ajn\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\2.5.2\libraries\ESP8266WiFi

I think this is the problem: you have two versions of `ESP8266WiFi` installed, and they might be conflicting. Remove the first one (in `C:\Users\ajn\Documents\Arduino\libraries\`) and try again.