digispark USB fun

README.md

Digispark doesn't allow using the normal Serial.println() that an arduino uses becuase it doesn't show up as a com port.

Instead you need to use hidapitester or https://github.com/Bluebie/digiusb.rb ruby app to read from USB data.

Digispark has VID/PID of 16C0/05DF

bluebie/digiusb

Start the digterm ruby app and enter 1 in the terminal. When 1 is pressed, the blue LED (pin 1) should turn on for 1/10 of a second

gh repo clone Bluebie/digiusb.rb
cd digiusb
gem install colored
gem intall libusb
./bin/digiterm
>hello world
>1 

main.cpp

// To upload this sketch to digispark, you must either use platform.io or a really old version of arduino on a 32 bit mac (64 bit wont work)
// You more than likely can't plug the digispark into a usb 3.0 port. Use a usb 2.0 port or a usb extenstion cable
// https://www.youtube.com/watch?v=hVQubqgdoZg
// To actually upload code with platform.io, click upload, then unplug/replugin in the device within 5 seconds. 

#include <Arduino.h>
#include <DigiUSB.h>

void setup() {
    pinMode(1, OUTPUT);
    digitalWrite(1,HIGH);
    delay(500);
    digitalWrite(1,LOW);
    DigiUSB.begin();
}

void get_input() {
  int lastRead;
  // when there are no characters to read, or the character isn't a newline
  while (true) { // loop forever
    if (DigiUSB.available()) {
      // something to read
      lastRead = DigiUSB.read();
      //If you type 1, it will turnon the LED for 100 ms
      if (lastRead == '1') {
        digitalWrite(1,HIGH);
        delay(100);
        digitalWrite(1,LOW);
      }
      DigiUSB.write(lastRead);
      
      if (lastRead == '\n') {
        break; // when we get a newline, break out of loop
      }
    }
    
    // refresh the usb port for 10 milliseconds
    DigiUSB.delay(10);
  }
}

void loop() {
  // print output
  DigiUSB.println("Waiting for input...");
  // get input
  get_input();
}

Send 42 from digispark to PC once a second

define USB_CFG_DEVICE_NAME     'D','i','g','i','B','l','i','n','k'
#define USB_CFG_DEVICE_NAME_LEN 9
#include <Arduino.h>
#include <DigiUSB.h>

void setup() {
    DigiUSB.begin();
    pinMode(0,OUTPUT);
    pinMode(1,OUTPUT);
    pinMode(2,OUTPUT);
}

unsigned long t = 0;
void loop() {
  DigiUSB.refresh();
  if (t==0 || millis() > t+1000) {
    digitalWrite(1, HIGH);
    delay(50);
    digitalWrite(1, LOW);
    DigiUSB.write(42);
    t = millis();
  }
}

hidapitester read data

hidapitester --vidpid 16C0:05DF --usagePage FF00 --open --read-feature 0 --close

2A = 42

Opening device, vid/pid:0x16C0/0x05DF, usagePage/usage: FF00/0
Device opened
Reading 64-byte feature report, report_id 0...read 2 bytes:
 00 2A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Closing device