Connecting spark core to an arduino mini

Hello everyone!
In a project I am doing, I am trying to send data from a sensor to an Arduino mini and from there to the spark core, up to the cloud, 1st of all, is it even possible?
in case it is, before I start doing it, I tried to do a simple thing, write some code on the Arduino mini
on the arduino site they tell to connect the arduino mini to a usb adapter, but I dont have any right now, so I tought to try and use the spark core! here are the arduino mini guide on how to connect: https://www.arduino.cc/en/Guide/ArduinoMini#connecting
I connect:
spark core \arduino mini
Vin - +5V
GND - GND
*V3.3 - RST
TX - RX
RX - TX
But for some reason, when I try to upload a sktech, it just gets stucks on the “Uploading” part forever

tl;dr: how to connect spark core to arduino mini

Thanks!