All works independently, but not together- human pulse project

So long story short- Im re-creating a low cost high fidelity medical training manikin (I run a medical nonprofit that needs it overseas- if you care for the “why”). Im new to arduino, but I thought up the design, tested everything independently, and then hired a guy to help me write the code and program it into an app that would allow me to do 2 things: Turn on/off a peristaltic pump that serves as “blood flow” and to adjust the frequency/min of vibrations of a coin vibrator that would simulate a human pulse.

Problem is:The app can connects successfully to the bluetooth, but then the buttons dont work (doesnt show an error message, just doesnt work/do anything). The only error message I have receive so far is “516- broken pipe” which only occurs if you’re not connected to bluetooth.

The only thing I can get it to do so far is get the pump to turn on, but it does not respond to the “off” button on the app. The coin vibrator now does nothing.
Steps Ive taken: double checked all the wiring. As far as I can tell its sound and all the connections are good. Changed from a 9V power supply to a 12v power supply and back and forth. No change (coin vibrator seemed a little more active - IE would randomly buzz- when on 9V power supply). Double checked all components individually to ensure they still work and are not shorted out. Switched arduino Uno boards.
Things Ive noticed, pin3 is only getting .28V when I measure with the multimeter- not sure why.
The guy who is helping me- says this is a wiring problem (he may be right) but for the life of me I cannot figure out what the problem is. I’m all for learning- so educate me… what am I doing wrong?

The picture where we can see it:

I don't see anything in the schematic. Can we see the code?

Not a code issue but, one thing I would *not *do is run the indicated ground out of the Arduino board. When the motor starts it's going to pull its starting current through the traces on the circuit board - and therefore generate a nice spike to nearby components. I'd wire that directly to the negative of the +12V supply.

mannequin schematic.PNG

mannequin schematic.PNG

The only error message I have receive so far is "516- broken pipe" which only occurs if you're not connected to bluetooth.

Doesn't sound like an Arduino message, and based on your explanation points to you not being connected on Bluetooth. So the Bluetooth connection itself would be the obvious place to start.

First, does the program run correctly using input from the serial monitor. You show that you are using an HC05 and you should be able to test what you want the hardware to do with Serial input from the monitor.

In regards to the Bluetooth debugging, I would recommend starting with a Serial Bluetooth Terminal app like the one from Kai Morich. Leave the custom app for development when everything is working like you want.