I have a project that controls two solenoids. I originally set it up with an Uno, and then switched it over to a Teensy 2.0 so everything would fit on a single small breadboard and into a small project box.
Everything works on both setups with the exact same code (except changing PIN numbers for the Teensy), except one thing.
On the Uno setup I have two pins from the Uno go to the respective first pins of the TIP120 transistors that control the solenoids. Pin 2 of each TIP120 goes to the ground of the solenoids. There's a 2.2K resistor between pin 1 and pin 3 of each transistor. A wire connects pin 3 of both TIP120s, and pin 3 from one of the transistors is connected to the ground of the 12V power supply. Lastly the live connections from both solenoids are connected, and then from there are connected to the 12V power supply.
This works perfectly on the Uno. On the Teensy only the solenoid that connects directly from pin 3 of of TIP120 to the 12V power supply is activated. The second solenoid is never activated, even though it's wired exactly the same as on the Uno. Any ideas why this setup would not work on the Teensy?
I've tried replacing the transistors, the resistors, the wires, and nothing seems to help. I can't figure out if there is something electrically different going on because of the Teensy. I can't imagine what that would be, but it seems like there is some difference that I'm not recognizing. Any help would be greatly appreciated.
Everything works on both setups with the exact same code (except changing PIN numbers for the Teensy), except one thing.
On the Uno setup I have two pins from the Uno go to the respective first pins of the TIP120 transistors that control the solenoids. Pin 2 of each TIP120 goes to the ground of the solenoids. There's a 2.2K resistor between pin 1 and pin 3 of each transistor. A wire connects pin 3 of both TIP120s, and pin 3 from one of the transistors is connected to the ground of the 12V power supply. Lastly the live connections from both solenoids are connected, and then from there are connected to the 12V power supply.
This works perfectly on the Uno. On the Teensy only the solenoid that connects directly from pin 3 of of TIP120 to the 12V power supply is activated. The second solenoid is never activated, even though it's wired exactly the same as on the Uno. Any ideas why this setup would not work on the Teensy?
I've tried replacing the transistors, the resistors, the wires, and nothing seems to help. I can't figure out if there is something electrically different going on because of the Teensy. I can't imagine what that would be, but it seems like there is some difference that I'm not recognizing. Any help would be greatly appreciated.