I've noticed that when I'm sending serial data to my computer's serial monitor, the tx light only lights up when the serial monitor is open. When I close the monitor, it seems to stop sending data. Is this a normal thing?
The reason I ask is because I'm really trying to send data from my esplora to an uno, and I notice that despite (1) having the grounds of both arduinos connected and (2) connecting the esplora's tx pin (reset_lcd) to the uno's rx pin (pin 0) and the esplora's rx pin (dc_lcd) to the uno's tx pin (pin 1), the tx light on the esplora and the rx pin on the uno don't light up at all.
What could be the problem?