SparkFun Forums

[theguitarman]

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!

[theguitarman]

Any help? Thanks!

[theguitarman]

Any help on this?

[amongstmyselves]

Howdy. It's worth you looking at this hookup guide - https://learn.sparkfun.com/tutorials/mp ... de-v24/all

Steve

[theguitarman]

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.

[TS-John]

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.

[robertsonics]

While it's written for the WAV Trigger, this post may be of some use:

https://robertsonics.com/2015/04/25/ard ... -tutorial/

[theguitarman]

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?

[theguitarman]

While it's written for the WAV Trigger, this post may be of some use:

https://robertsonics.com/2015/04/25/ard ... -tutorial/

Thanks! Helpful, but they still only connect the ground between the two boards here, is that actually necessary if they use a common ground via barrel plugs?

[TS-Chris]

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 and TX pins on the other.

[TsunamiQuestion]

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.

Sounds good for the MP3 trigger board but what about the Tsunami? The only documentation I was able to locate has the hookup guide (https://learn.sparkfun.com/tutorials/ts ... -guide/all) and the WAV hookup guide (http://robertsonics.com/2015/04/25/ardu ... -tutorial/) but that doesn't allow for Rx commands like the Tsunami does and it runs at 5V, not 3.3V so hooking the Tsunami up like that would not be a good idea.

Trying to figure out the best way to convert a 5V Arduino into being able to send and receive simple commands to the Tsunami board and the documentation isn't really easily locatable and it certainly isn't in one place. Maybe consider putting it together a little bit better so one can more easily locate it?

https://github.com/robertsonics/Tsunami ... al-Library sort of speaks to this a bit but also glosses over how to physically wire things up and also glosses over what type of level shifter is needed.

Digging even deeper into the actual Github Arduino INO file documentation notes there is at least a bit of information on how to actually wire up the Tsunami:

https://github.com/robertsonics/Tsunami ... miDemo.ino

To use this sketch with an Arduino, you'll need:

1) An Arduino with an operating voltage of 3.3V, *** NOT 5V ***!
2) Download and install the Metro library.
3) Connect 3 wires from the Arduino to the Tsunami's serial connector:

Arduino Tsunami
======= =======
GND <------> GND
TXn <------> RX
RXn <------> TX

But do we need https://learn.sparkfun.com/tutorials/bi ... -guide/all or something more like https://learn.sparkfun.com/tutorials/tx ... okup-guide or https://www.sparkfun.com/products/14765 if we are using a 5V native Arduino?

It's still unclear what type of "serial" the Tsunami even uses? TTL? RS232?

What kind of serial speeds is the Tsunami capable of using?

Lastly, the Metro library has been depreciated for a good while now as well. https://github.com/SofaPirate/Chrono is the latest revision.

[TsunamiQuestion]

Here is a quick list of common Arduino Serial port pinouts for reference.

https://www.arduino.cc/reference/en/lan ... on/serial/

Note that on the Uno, Nano, Mini, and Mega, pins 0 and 1 are used for communication with the computer. Connecting anything to these pins can interfere with that communication, including causing failed uploads to the board. Also note that this serial appears to be TTL.

To use the serial pins to communicate with an external TTL serial device, connect the TX pin to your device’s RX pin, the RX to your device’s TX pin, and the ground of your Mega to your device’s ground.

Also note:
https://www.arduino.cc/en/pmwiki.php?n=Reference/Serial

The Arduino Mega has three additional serial ports: Serial1 on pins 19 (RX) and 18 (TX), Serial2 on pins 17 (RX) and 16 (TX), Serial3 on pins 15 (RX) and 14 (TX). To use these pins to communicate with your personal computer, you will need an additional USB-to-serial adaptor (sic), as they are not connected to the Mega's USB-to-serial adaptor (sic). To use them to communicate with an external TTL serial device, connect the TX pin to your device's RX pin, the RX to your device's TX pin, and the ground of your Mega to your device's ground.

[TsunamiQuestion]

https://learn.sparkfun.com/tutorials/se ... munication

Minor typo there?

Hardware Implementation

We've covered asynchronous serial from a conceptual side. We know which wires we need. But how is serial communication actually implemented at a signal level? In a variety [of?] ways, actually.

[TS-Chris]

If you see a typo or issue on a page on the SparkFun site, please PM TS-Feedback to let us know.
Thanks!

[TsunamiQuestion]

If you let us delete or edit messages, I could just delete it after it has been corrected? Not sure how we were supposed to know to PM TS-Feedback but that works too. Can you clarify some of the above questions about the TTL voltage level conversion. Trying to locate a suitable Sparkfun product but several of them have asterisks about ways they do and ways they do not work well and none of them seem to handle Serial TTL and SPI and I2C and higher speeds very well. Not even sure what the highest level speed the Tsunami supports, they seem to use 9600 in the examples but that may or may not be fast enough depending on what we are sending it.

Also, the https://learn.sparkfun.com/tutorials/ts ... okup-guide page suggests using the https://www.sparkfun.com/products/11771 product? Unclear if that's the best approach to take or not for use with the Tsunami or if the SparkFun Logic Level Converter - Bi-Directional BOB-12009 would be just as good?

http://robertsonics.com/tsunami-user-guide/ says that the Serial Baudrate: This sets the baudrate for the async serial port. This baudrate will remain in effect until the next power cycle. The default is 57.6kbps. but then why does the official supplied Arduino sketch use 9600 bps?