Older Teensy 2.0 no Serial Monitor Output Help


New here.... I'm building an older power switch that was designed around a Teensy 2.0

I get a timeout error on the windows software so I thought I'd check the basics

1). I can program the firmware to the Teensy using ardiuno and it works

2). When I click on serial monitor I get error messages. Please see photos of the errors connecting to serial monitor. The 2 different errors are testing a usb2 port and usb3 port on the computer.


Here is the simple code

// the setup function runs once when you press reset or power the board
void setup() {
// initialize digital pin LED_BUILTIN as an output.
pinMode(11, OUTPUT); // built in LED
pinMode(4, OUTPUT);
pinMode(7, OUTPUT);
pinMode(8, OUTPUT);
pinMode(9, OUTPUT);
pinMode(21, OUTPUT);
pinMode(24, OUTPUT);
int val;
// the loop function runs over and over again forever
void loop()
val = analogRead(0);
Serial.print("analog 0 is: ");
digitalWrite(11, HIGH); // turn the LED on (HIGH is the voltage level)
digitalWrite(9, HIGH);
delay(500); // wait for a second
digitalWrite(11, LOW); // turn the LED off by making the voltage LOW
digitalWrite(9, LOW);
delay(100); // wait for a second
From the screenshot, this looks like Arduino 1.8.x with Teensyduino 1.56 installed by Boards Manager.

For Arduino IDE older than 2.0.0, you need to use the installer. Boards Manager only works for Teensy if using Arduino 2.0.0 or later. Arduino 1.8.19 and earlier don't have all the features needed. A special installer is required to get a working setup on those older versions of Arduino IDE.

Get the installer here: (scroll down to "Arduino 1.8.x Software Development")

Also work mentioning Teensyduino 1.57 is the first version which works if a Boards Manager package is present. So if you wish to use both Arduino 1.8.19 and 2.0.4 on the same PC, the installation on 1.8.19 must be Teensyduino 1.57 or later. If you install 1.56, it will be messed up by presence of the Boards Manager installed copy.
Thanks so much!

I installed the latest of Arduino and Teensy loader and the serial port is working

However I still can't get the main program to work. I've been trying for over a week.... many hours....

The project is here

and the software is here

I've programmed the HEX file and upload it to Teensy but the windows program gives a timeout error.

I can see the Teensy 2 in USBDview with the komahub name meaning the firmware is working at some level.


Anyway I'm lost and if you can provide any help it would be greatly appreciated.

Photo of my hardware board

Quick followup to this old thread. For the next version of Teensyduino, I'm adding a check for the installed location if running on Windows. If Teensyduino appears to in a pathname installed by Boards Manager, but Arduino IDE doesn't give identifying info (which is only present in 2.0.0 and higher), then it will print a warning message to advise about needing to run the installer.

This can't solve the other problems, of a program which doesn't work and gives little or no info about why, but hopefully it can at least help people in the future to avoid the first problem encountered on this thread.