How to reset a Pico after USB HID examples?

[espruino-discuss]

Posted at 2017-11-14 by ClearMemory041063

A question concerning this example page.
Espruino USB HID

If you copy one of the examples into the WebIde, send it to a Pico, and save it, how can you restore the Pico to its original state?
Perhaps rig a push button on a pin and do a setwatch on that pin that does a reset()?

[espruino-discuss]

Posted at 2017-11-14 by @gfwilliams

Yes, if you've remembered you could do a reset in software :)

Otherwise have a look in Troubleshooting (http://www.espruino.com/Troubleshooting), under Espruino stopped working after I typed save() - there are some instructions there.

The last-ditch option is just to reflash your board, which will wipe out any saved code :)

---

Posted at 2017-11-15 by ClearMemory041063

Had time to try the mouse driver today. Here's the code:

//mymouse.js
// 15 Nov 2017
//
// Use pushbutton on pin B3 to reset
// Loads mouse driver into the USB boot
// Every second move mouse cursor by 20 pixels
// in a square pattern
//
//load and save the program
// unplug and replug the Pico USB
// mouse cursor should be moving in square pattern
// reconnect to WebIde
// mouse cursor still moving
// Type reset() in left  pane of WebIde
// Type save() in left pane of WebIde


var mouse = require("USBMouse");

// A way back to normal just in case
var but1=B3;
setWatch(function(){
  console.log("endit");
  reset();
},but1, {debounce:100,repeat:true, edge:"falling"});

var i=0;
setInterval(function () {
//console.log(i);
  switch (i){
    case 0:
      mouse.send(0, 20, mouse.BUTTONS.NONE); // X movement, Y movement,
    break;
    case 1:
      mouse.send(20, 0, mouse.BUTTONS.NONE); // X movement, Y movement,
    break;
    case 2:
      mouse.send(0, -20, mouse.BUTTONS.NONE); // X movement, Y movement,
    break;
    case 3:
      mouse.send(-20, 0, mouse.BUTTONS.NONE); // X movement, Y movement,
    break;
  }
  i++;
  if( i>3) i=0;
}, 1000);

It's interesting that the WebIde still talks through the USB port with the mouse functions.

---

Posted at 2017-11-16 by @gfwilliams

Great!

It's interesting that the WebIde still talks through the USB port with the mouse functions.

Yes, that took a long time to get working right :)

---

Posted at 2017-11-16 by ClearMemory041063

I've been searching for some Vogan poetry to further understand what is going on. Some of it gets really deep in the weeds.
Here is a link that seems to be about the right level to start with.

Usb Made Simple

It covers the hardware and bus messages but importantly the Descriptors that are used in the module.

This tool looks like it could be useful for creating a descriptor

HID Descriptor Tool from USB.org

@gfwilliams Espruino continues to amaze!

---

Posted at 2017-11-16 by ClearMemory041063

Annotate the report descriptor

/* Annotate the report descriptor 
http://www.usbmadesimple.co.uk/ums_g_an_ms_8.gif
*/
/* Copyright (c) 2015 Gordon Williams, Pur3 Ltd. See the file LICENSE for copying permission. */
/* 

var mouse = require("USBMouse");

setWatch(function() {
  mouse.send(20,20,mouse.BUTTONS.NONE); // X movement, Y movement, buttons pressed
}, BTN, {debounce:100,repeat:true, edge:"rising"});


*/
/*
E.setUSBHID ⇒

(top)
Call type:

E.setUSBHID(opts)
Description

USB HID will only take effect next time you unplug and re-plug your Espruino. If you're disconnecting it from power you'll have to make sure you have save()d after calling this function.

Note: This is only available in devices that support USB HID (Espruino Pico and Espruino WiFi)

Parameters

opts - An object containing at least reportDescriptor, an array representing the report descriptor. Pass undefined to disable HID.
*/
E.setUSBHID({
  reportDescriptor : [
  0x05,   0x01, //Usage Page (Generic Desktop Controls)
  0x09,   0x02, //Usage (Mouse)
  0xA1,   0x01, //Collection (application)
  0x09,   0x01, //Usage (Pointer)

  0xA1,   0x00, //Collextion (Physical)
  0x05,   0x09, //Usage Page (Button)
  0x19,   0x01, //Usage Minimum (1)
  0x29,   0x03, //Usage Maximum (5)

  0x15,   0x00, //Logical Minimum (0)
  0x25,   0x01, //Logical Maximum (5)
  0x95,   0x03, //Report Count (3)
  0x75,   0x01, //Report Size (1)

  0x81,   0x02, //Input (Data, Variable,Absolute,Bit Field)
  0x95,   0x01, //Report Coint (1)
  0x75,   0x05, //Report Size (5)
  0x81,   0x01, //Input (Constant, Array, Absolute, Bit Field)

  0x05,   0x01, //Usage Page (Generic Desktop Controls)
  0x09,   0x30, //Usage 00
  0x09,   0x31, //Usage (X)
  0x09,   0x38, //Usage (Wheel)

  0x15,   0x81, //Logical Minimum(-127)
  0x25,   0x7F, //Logical Maximum(127)
  0x75,   0x08, //Report Size (8)
  0x95,   0x03, //Report Count (3)

  0x81,   0x06, // Input (Data, Variablr,Relative, Bit Field)
  0xC0,  //End Collection

  0x09,  0x3c, // ?????
  0x05,  0xff, 
    
  0x09,  0x01, 
  0x15,  0x00, 
  0x25,  0x01, 
    
  0x75,  0x01, 
  0x95,  0x02, 
  0xb1,  0x22, 
    
  0x75,  0x06, 
  0x95,  0x01, 
  0xb1,  0x01, 
  0xc0  //end collection
]
});

exports.BUTTONS = {
  NONE : 0,
  LEFT : 1,
  RIGHT : 2,
  MIDDLE : 4
};

exports.send = function(x,y,b) {
  E.sendUSBHID([b&7,x,y,0]);
};


/*
E.sendUSBHID ⇒

(top)
Call type:

E.sendUSBHID(data)
Parameters

data - An array of bytes to send as a USB HID packet

Returns

1 on success, 0 on failure
*/