When I first bought Adafruit's Trinket, I was experiencing an issue with my Windows 7 desktop PC.
I could not get my Trinket's red LED to pulsate for 10 seconds after it had power. As it was suppose to do (http://learn.adafruit.com/introducing-trinket/starting-the-bootloader).
I finally was able to get the Trinket to work correctly by adding a powered USB hub to my desktop PC. I assume that it may have been a power issue, but I am still uncertain.
I am using Adafruit's Trinket to create a simple HID keyboard 'Enter' button.
I started by using the example sketch "TrinketKeyboardExample" and modifying it.
The button is actually an emergency stop button with a normally closed switch.
This is the original code "TrinketKeyboardExample":
/*
TrinketKeyboard example
For Trinket by Adafruit Industries
*/
#include <TrinketKeyboard.h>
#define PIN_BUTTON_CAPITAL_A 0
#define PIN_BUTTON_STRING 2
void setup()
{
// button pins as inputs
pinMode(PIN_BUTTON_CAPITAL_A, INPUT);
pinMode(PIN_BUTTON_STRING, INPUT);
// setting input pins to high means turning on internal pull-up resistors
digitalWrite(PIN_BUTTON_CAPITAL_A, HIGH);
digitalWrite(PIN_BUTTON_STRING, HIGH);
// remember, the buttons are active-low, they read LOW when they are not pressed
// start USB stuff
TrinketKeyboard.begin();
}
void loop()
{
TrinketKeyboard.poll();
// the poll function must be called at least once every 10 ms
// or cause a keystroke
// if it is not, then the computer may think that the device
// has stopped working, and give errors
if (digitalRead(PIN_BUTTON_CAPITAL_A) == LOW)
{
TrinketKeyboard.pressKey(KEYCODE_MOD_LEFT_SHIFT, KEYCODE_A);
// this should type a capital A
TrinketKeyboard.pressKey(0, 0);
// this releases the key
}
if (digitalRead(PIN_BUTTON_STRING) == LOW)
{
// type out a string using the Print class
TrinketKeyboard.print("Hello World!");
}
}
Here is my modified code:
/*
TrinketKeyboard example
For Trinket by Adafruit Industries
Modified by PlatinumFusion
*/
#include <Bounce.h>
#include <TrinketKeyboard.h>
//#define button0 0
#define PIN_BUTTON_STRING 2
Bounce button0 = Bounce(0, 10);
void setup()
{
// button pins as inputs
pinMode(0, INPUT_PULLUP);
// setting input pins to high means turning on internal pull-up resistors
digitalWrite(0, LOW);
// remember, the buttons are active-low, they read LOW when they are not pressed
// start USB stuff
TrinketKeyboard.begin();
}
void loop()
{
TrinketKeyboard.poll();
button0.update();
// the poll function must be called at least once every 10 ms
// or cause a keystroke
// if it is not, then the computer may think that the device
// has stopped working, and give errors
if (button0.risingEdge()) {
TrinketKeyboard.pressKey(0, KEYCODE_ENTER);
// this should be the 'Enter' key
TrinketKeyboard.pressKey(0, 0);
}
}
The total cost of this project comes to about $70, but keep in mind that this is the bare minimum material to create a remote relay with Bluetooth . I used a breadboard, so you would need to find a box to put it all together and make it nice and neat. Also, I used batteries to power the ATtiny, Bluetooth, and Relay Switch.
