I’m unclear on which FTDI breakout I need to program the Papa Soundie. Will the 5V breakout work for programming it, or do I need to add a 3.3V FTDI breakout to my toolbox? The schematic indicates the FTDI VCC is RAW, which would indicate that 5V would work. Am I reading that correctly? Or is there an error on the schematic?
Since I don’t have a 3.3V breakout, could I connect VCC from the breakout to VIN instead VCC on the Soundie?
Hi DennyMo,
The VIN of the PapaSoundie is 5V tolerant but the I/O logic is only 3.3V so you will need to either purchase a 3.3V FTDI or you can just adjust the jumper on the back of your 5V FTDI to swap it to 3.3V. [This example from our “Working with Jumpers and PCB Traces Guide” covers exactly how to swap the Vcc and logic of your 5V FTDI.
Let us know if you have any other questions or concerns about these or other SparkFun products in your project and we would be happy to help as much as we can.](https://learn.sparkfun.com/tutorials/how-to-work-with-jumper-pads-and-pcb-traces#cutting-a-trace-between-jumper-pads)
Thanks for the info. Since most of my Arduinos are 5V, I’d rather not have a permanent modification to 3.3V. Would it be possible to add pins and a use a jumper to make the swap? Is the spacing right to use PRT-09015 headers and PRT-09044 jumpers? Or would you recommend something different?
Would my idea of connecting VCC on the FTDI to VIN on the Soundie work in a pinch?
Thanks.
Hi again DennyMo,
The jumper modification is only semi-permanent and you can swap back to 5V whenever you would like but it is a bit of a hassle since you would need to get out your soldering iron each time you wanted to go between 5V and 3.3V. The spacing of the jumper pads is too small for that header, unfortunately. You could remove the header pins from the housing and manually place them but that might be more hassle than it is worth and then you’re stuck with trying to find a jumper small enough to fit on those pins.
If you do not want to modify the jumper, the next best option outside of getting a 3.3V FTDI would be to level shift the serial pins on the 5V FTDI down to 3.3V. You can either use a [Logic-level shifter or you could create a [voltage divider if you have some resistors available. There is a calculator in that tutorial I linked that can help you find the right values to go from 5V to 3.3V.
Finally, you can use VIN to power the Papa Soundie with 5V but you will still need to shift the serial signals down to 3.3V to upload to the board. Connecting 5V logic to the serial header will most likely not immediately damage the ATMega328 but continuous use will eventually cause some damage to it and the board will no longer function properly.](https://learn.sparkfun.com/tutorials/voltage-dividers)](https://www.sparkfun.com/categories/361)
Thx for the details. You’ve certainly convinced me that the easiest way forward is to get a second FTDI. 
Having both a 5V FTID and a 3.3V one are must-have for a lot of folks at SparkFun so I cannot disagree! If you have any other questions about the Papa Soundie or other SparkFun products you are using, let us know and we would be happy to help!
Happy Hacking!