Resetting an Adafruit Trinket using an Arduino Uno

satb100Sometimes when you’re designing electronic circuit boards especially on a budget it’s easy to cut corners and only put the very bare essentials into the board. But the folks at Adafruit Industries make quality inexpensive products and they never cut corners. Case in point is there new ATtiny85 development boards the Adafruit Trinket and Adafruit Gemma. Other boards using the ATtiny85 require you to physically unplug and re-plug their boards every time you want to load a new sketch. On the other hand Adafruit included a reset button and they broke out the reset line on one of the breakout pins. For most people that’s probably not a big deal but for someone with a disability with myself, the inability to physically plug and unplug the board is a dealbreaker. Thanks to Adafruit including this reset breakout I was able to use another microcontroller namely an Arduino Uno to toggle the reset for me and allow me to use the board despite my disability. Here is a demo video I created for the weekly Adafruit Show-and-Tell.

Here is a code used on the Arduino Uno to toggle the pin 5 low for 1/10 of a second
//Sends reset signal from Arduino to
//Adafruit trinket by pulsing the reset line
//low for 1/10 of a second
int reset_pin = 5;
void setup() {
pinMode(reset_pin, OUTPUT);
digitalWrite(reset_pin, HIGH);
delay(100);
digitalWrite(reset_pin, LOW);
delay(100);
digitalWrite(reset_pin, HIGH);
}
void loop() {
}

Here is the code that you load onto the trinket so that it will blink a particular pattern. That verifies that you successfully uploaded.
//Modified trinket blink sketch
int led = 1; // blink pin 1 the built in red LED
void setup() {
pinMode(led, OUTPUT);
}
void Signal (char N,int T) {
for(int i=0;i

Here is the Adafruit Show-and-Tell from September 21, 2013 where I demonstrated this project.