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Post about any product in the Audio category on the SparkFun website: https://www.sparkfun.com/categories/273
By theguitarman
#201396
Hello,

I am currently wiring up my MP3 Trigger Board, and powering it via the barrel plug. In this setup, there USB/EXT switch on the board provides an on/off switch.

I am trying to communicate to the MP3 Trigger Board via serial commands from an Arduino Mega. The Mega is also powered by barrel plug, so these two board should, in theory, share a common ground and power source. To connect from an output pin of the Mega to the Rx pin of the MP3 Trigger Board, what wires do I need to connect? Do I need to connect the ground to the common ground? Do I need to provide 5V from the Mega to the MP3 trigger board? Does the switch need to be in the Ext position to receive commands via serial?

Thanks!
By theguitarman
#202419
Thanks Steve, I have been through it a few times but, while it does specifically describe Serial commands, it never suggests the proper wiring for Serial control. It remains unclear to me if, when using Serial commands connected from an external controller, it is required to provide 5V and GND to the FTDI header pins, or if you can simply connect the Rx and Tx pins and continue supplying 5V/GND using the barrel plug.
User avatar
By TS-John
#202421
Wiring from a Mega powered via barrel jack to the MP3 trigger it should look like:

Mega pin MP3 Trigger pin off FTDI 6 pin header
5V > VCC - Regulated 5v of Mega should provide enough current to power the MP3 Trigger.
GND > GND
TX1 > RX
RX1 > TX - Optional if you want the Mega to listen for data from the MP3 Trigger.

Switch should be flipped to "USB". The power LED on the MP3 Trigger should turn on if everything is hooked up properly.

Should do it. I recommend not using the hardware TX0 pin off of the Mega because if you leave this hooked up to the MP3 Trigger you could brick it when uploading a new sketch to the Mega.

Hope this helps.
By theguitarman
#202449
TS-John wrote: Tue Mar 12, 2019 8:45 am Wiring from a Mega powered via barrel jack to the MP3 trigger it should look like:

Mega pin MP3 Trigger pin off FTDI 6 pin header
5V > VCC - Regulated 5v of Mega should provide enough current to power the MP3 Trigger.
GND > GND
TX1 > RX
RX1 > TX - Optional if you want the Mega to listen for data from the MP3 Trigger.

Switch should be flipped to "USB". The power LED on the MP3 Trigger should turn on if everything is hooked up properly.

Should do it. I recommend not using the hardware TX0 pin off of the Mega because if you leave this hooked up to the MP3 Trigger you could brick it when uploading a new sketch to the Mega.

Hope this helps.
Thanks for the reply. Two follow up questions

1) Are you saying that you cannot power the MP3 Trigger Board via barrel plug while using the Tx and Rx pins?

2) I realize that the hardware TX0 of the Mega is used during uploads, but what about this process could brick the MP3 Trigger?
User avatar
By TS-Chris
#202454
You will need a common ground between the two boards, in addition, you will need to connect the TX and RX pins from one board to the RX ant TX pins on the other.