Arduino Pro Mini 328 5v/16MHz FTDI breakout reset

I have been playing with the Arduino Pro Mini and FTDI breakout that I ordered from SparkFun. I am having an odd issue with the reset. All of my sketches upload fine, but i need to disconnect either the USB cable or the FTDI from the mini and reconnect it in order for the sketch to start running. If I upload the blink sketch the led blinks without needing to disconnect. When I run the blink test for my finger print scanner the serial debug prints one line, normally it prints on each blink, and hangs until i plug / unplug. Before i unplug if I hit the onboard reset, or ground the reset pin, I get the same single serial print. All of my google searches have turned up people having issues with the upload and not the reset. I have tried selecting the different boards for the drop-down menu. It was late last night and i though i got it working at some point, not sure what i did, then it suddenly stopped. This really isn’t a huge issue as i can just plug / unplug when ever I upload. It is driving me a little crazy. I’m working on an iMac running 10.9 and I have downloaded and installed the latest FTDI drivers. Is there some sort of arduino hard and soft reset that i don’t know about?

Pro Mini 328 5v/16MHz https://www.sparkfun.com/products/11113

FTDI Basic Breakout https://www.sparkfun.com/products/9716

Fingerprint Scanner https://www.sparkfun.com/products/13007

So I made some progress on this last night. The Mini is defiantly resetting but there is something going on with my connected devices. I have an I2C Adafruit Trellis keypad hooked up to pins A4 and A5 and the fingerprint scanner is on pins 4 and 5 using software serial. Both devices are 5V so I have them hooked up on VCC. I think what is happening is that neither of these devices reset with the Mini. I’m my setup routine I blink the LEDs on the keypad and the fingerprint scanner. After sketch upload the keypad and the fingerprint scanner blink like they should, but the keypad doesn’t light up the buttons when I press them. They do if I reset all of the power to the board. It’s appears that after the sketch upload the setup function is ran but it never enters into the loop. Has anyone experienced this?

Trellis https://www.adafruit.com/product/1616

smp4488:
I think what is happening is that neither of these devices reset with the Mini.

Of course they wouldn’t, you don’t have them hooked up that way…

It’s appears that after the sketch upload the setup function is ran but it never enters into the loop.

How can we help you without seeing your code?

Here is a link to my code on a GItHub repository https://github.com/smp4488/trellis-lock. It’s still a work in progress. When I run the same code on my Duemilanove the keypad resets fine. Does the Duemilanove reset the 5V/3V lines on reset?

My guess is that your code is resetting after the code is uploaded, but your keypad is not. Your code is then trying to initialize the keypad and for some reason your code is hanging at this point. Feel free to email techsupport@sparkfun.com and they might be able to help you out a bit more.

Sorry I didn’t get back to you sooner.

You are right in stating the Trellis isn’t resetting. In the datasheet, on the HT16K33 (the Trellis controller) the only way to reset it, is to turn off the power for a few milliseconds. When power is applied again, there is a wait time of 1ms. The only way to reset the Trellis is to connect the positive supply to one of the Arduino pins. This way you can control when power is supplied. In theory, when you reset the Arduino is should also disconnect the supply to the Trellis.

NOTE: By doing this, you run the risk of damaging the Arduino pin. You can test my suggestion to see if it works and if it does, use that pin to control a transistor to switch the power supply to the Trellis. The Trellis requires 200mA when all the LEDs are lit. If you have it setup where the LEDs are not lit up all at once, you can get by without the transistor.

And Michelle, please refer to this thread. https://forum.sparkfun.com/viewtopic.ph … 59#p172870. Specifically the last paragraph.