user667: 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?

user37622: Esplora is based on a MCU with native USB. The native USB reports connected only when it really connects. You have in setup() a while loop until the USB Serial is valid. The skech waits there for connection. Comment out the while (Serial) loop.
The TX and RX LEDs of Esplora are connected to the native USB port Serial interface. They will not light for the Serial1 interface.
You should disconnect the Uno from computer to not disturb the Serial interface with USB connection. Or use SoftwareSerial to communicate with Esplora and have debug prints to Serial Monitor.

667: <p>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?  </p>

<p>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.  </p>

<p>What could be the problem?</p>
 37622: <p>Esplora is based on a MCU with native USB. The native USB reports connected only when it really connects. You have in setup() a while loop until the USB Serial is valid. The skech waits there for connection. Comment out the while (Serial) loop.</p>

<p>The TX and RX LEDs of Esplora are connected to the native USB port Serial interface. They will not light for the Serial1 interface.</p>

<p>You should disconnect the Uno from computer to not disturb the Serial interface with USB connection. Or use SoftwareSerial to communicate with Esplora and have debug prints to Serial Monitor.</p>
