USB-teletype - Revision history

Morris: /* To-Do List */

2017-02-28T01:27:21Z

To-Do List

Morris: /* Known Bugs */

2017-02-28T01:26:41Z

Known Bugs

Morris at 04:22, 21 May 2016

2016-05-21T04:22:52Z

Morris at 22:45, 4 May 2016

2016-05-04T22:45:08Z

Morris at 07:14, 2 May 2016

2016-05-02T07:14:41Z

Morris at 06:44, 2 May 2016

2016-05-02T06:44:28Z

Morris: /* Modification and firmware updates */

2016-04-26T07:48:12Z

Modification and firmware updates

Morris at 07:44, 26 April 2016

2016-04-26T07:44:49Z

Morris: /* Modification */

2016-04-26T07:43:56Z

Modification

Morris at 07:18, 26 April 2016

2016-04-26T07:18:34Z

@@ Line 30: / Line 30: @@
 ==To-Do List==
 Firmware improvements being considered are:
-* transparent 7 or 8 bit passthrough mode for use with 33s and the like. (written, being tested)
+* transparent 7 or 8 bit passthrough mode for use with 33s and the like. (done, included in shipped firmware)
 * The ability, from the config command mode, to modify the ascii/baudot character translation table (done 4/2016)
 * the ability to select from multiple stored translation tables (done)
 * handle sending and receiving BREAK signals (done)
-* automatically sending pre-recorded messages like RYRYRYRY and quick brown fox (present but experimental)
+* automatically sending pre-recorded messages like RYRYRYRY and quick brown fox (present but experimental, included in shipped firmware)
 ==Known Bugs==

@@ Line 39: / Line 39: @@
 * In Linux, if you press the button on the adapter board immediately after first connecting it to the host, but before opening it with a terminal program, it will hang and have to be disconnected and reconnected.
 * Most of the commands/options listed as "experimental" in the documentation lack thorough safety checks or bounds checking.
 * When put into firmware-update (DFU) mode, the loop is opened.
-* 8-bit (ASR33, etc) mode is currently untested on real hardware.
+* <s>8-bit (ASR33, etc) mode is currently untested on real hardware.</s> It's been reported to work correctly on an ASR33.
 ==Schematic==
 [[File:loop-adapter1.png|800px]]

← Older revision		Revision as of 04:22, 21 May 2016
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		+	'''[https://www.youtube.com/user/teletweety/videos?sort=dd&view=0&shelf_id=0 Action videos!]'''
		+
	This is a compact USB current loop serial adapter on a 1.6 by 1.4 inch pc board. It connects to a computer running Windows, Mac OSX, Linux, Android, or probably anything else via a USB Mini-B connector, and presents itself as a USB serial port, while the other end connects directly in series with a teletype loop (or pair of loops, if full duplex). Data is relayed bidirectionally between the two. It does not generate loop current itself, so a loop power supply with fuse is needed if not already present. Download the [[Media:usbtty-instructions.pdf\|instruction sheet]] or the windows INF file[http://teletweety.com/usbtty_adapter.inf].		This is a compact USB current loop serial adapter on a 1.6 by 1.4 inch pc board. It connects to a computer running Windows, Mac OSX, Linux, Android, or probably anything else via a USB Mini-B connector, and presents itself as a USB serial port, while the other end connects directly in series with a teletype loop (or pair of loops, if full duplex). Data is relayed bidirectionally between the two. It does not generate loop current itself, so a loop power supply with fuse is needed if not already present. Download the [[Media:usbtty-instructions.pdf\|instruction sheet]] or the windows INF file[http://teletweety.com/usbtty_adapter.inf].

← Older revision		Revision as of 22:45, 4 May 2016
Line 1:		Line 1:
−	This is a compact USB current loop serial adapter on a 1.6 by 1.4 inch pc board. It connects to a computer running Windows, Mac OSX, Linux, Android, or probably anything else via a USB Mini-B connector, and presents itself as a USB serial port, while the other end connects directly in series with a teletype loop (or pair of loops, if full duplex). Data is relayed bidirectionally between the two. It does not generate loop current itself, so a loop power supply with fuse is needed if not already present. Download the [[Media:usbtty-instructions.pdf\|instruction sheet]] or the windows INF file[http://teletweety.com/usbtty_adapter.inf].	+	This is a compact USB current loop serial adapter on a 1.6 by 1.4 inch pc board. It connects to a computer running Windows, Mac OSX, Linux, Android, or probably anything else via a USB Mini-B connector, and presents itself as a USB serial port, while the other end connects directly in series with a teletype loop (or pair of loops, if full duplex). Data is relayed bidirectionally between the two. It does not generate loop current itself, so a loop power supply with fuse is needed if not already present. Download the [[Media:usbtty-instructions.pdf\|instruction sheet]] or the windows INF file[http://teletweety.com/usbtty_adapter.inf].
		+
		+	'''[http://teletweety.com/usbtty_adapter.html Trouble installing INF file on windows?]'''

	[[File:loop-adapter3.jpg\|450px]]		[[File:loop-adapter3.jpg\|450px]]

@@ Line 1: / Line 1: @@
-This is a compact USB to teletype current loop interface on a 1.6 by 1.4 inch pcb. It connects to a computer running Windows, Mac OSX, Linux, Android, or probably anything else via a USB Mini-B connector, and presents itself as a USB serial port, while the other end connects directly in series with a teletype loop. Data is relayed bidirectionally between the two. It does not provide loop current itself, so a loop power supply with fuse is needed if not already present. Download the [[Media:usbtty-instructions.pdf|instruction sheet]] or the windows INF file[http://teletweety.com/usbtty_adapter.inf].
+This is a compact USB current loop serial adapter on a 1.6 by 1.4 inch pc board. It connects to a computer running Windows, Mac OSX, Linux, Android, or probably anything else via a USB Mini-B connector, and presents itself as a USB serial port, while the other end connects directly in series with a teletype loop (or pair of loops, if full duplex). Data is relayed bidirectionally between the two. It does not generate loop current itself, so a loop power supply with fuse is needed if not already present. Download the [[Media:usbtty-instructions.pdf|instruction sheet]] or the windows INF file[http://teletweety.com/usbtty_adapter.inf].
 [[File:loop-adapter3.jpg|450px]]
@@ Line 29: / Line 29: @@
 * The ability, from the config command mode, to modify the ascii/baudot character translation table (done 4/2016)
 * the ability to select from multiple stored translation tables (done)
-* hand sending and receiving BREAK signals (done)
+* handle sending and receiving BREAK signals (done)
-* sending pre-recorded messages like RYRYRYRY and quick brown fox with short commands (experimental)
+* automatically sending pre-recorded messages like RYRYRYRY and quick brown fox (present but experimental)
 ==Known Bugs==

@@ Line 20: / Line 20: @@
 The controller is an Atmel atmega32u2 with a USB DFU-class bootloader installed via which the firmware can be updated or replaced.  To activate the bootloader, briefly short the two bare pads on the board marked "RST" - the orange LED will go out, and the green LED will blink slowly. The host computer will see the USB serial device disappear and be replaced with one called "Atmel DFU". You can read and program the chip using Atmel's FLIP software[http://www.atmel.com/tools/FLIP.aspx] on most platforms, and the commandline tool "dfu-programmer" on Linux and Mac OSX. On windows you will also need a driver for it, which is provided in the FLIP download; all other OS's don't require any driver. To exit the bootloader, issue a DFU reset command or just power cycle the board.
-The bootloader uses 4kB of flash, leaving 28kB free for application software.  In addition to the USB bootloader, the hardware ISP programming lines are brought out on the back side of the board on labeled pogo-pin pads, allowing replacement of the bootloader, recovery from any kind of software corruption, or eliminating the bootloader entirely to gain flash space. Source code for the current firmware is freely available on github[http://github.com/epvuc/usb-tty]. If I make updates or changes to the firmware, I'll release them as intel-format hex files which can be flashed to the board using the DFU bootloader, which can be activated
+The bootloader uses 4kB of flash, leaving 28kB free for application software.  In addition to the USB bootloader, the hardware ISP programming lines are brought out on the back side of the board on labeled pogo-pin pads, allowing replacement of the bootloader, recovery from any kind of software corruption, or eliminating the bootloader entirely to gain flash space. Source code for the current firmware is freely available on github[http://github.com/epvuc/usb-tty]. If I make updates or changes to the firmware, I'll release them as intel-format hex files which can be flashed to the board using the DFU bootloader.
 ==To-Do List==

@@ Line 17: / Line 17: @@
 The circuit board is physically divided in half. The loop-interface side is 100% completely electrically isolated from the computer interface side. If operating the board without an enclosure, it is '''very important''' to insure that nothing conductive comes in contact with it that might bridge exposed contacts and potentially carry high loop voltage anywhere near your computer's USB interface. The loop side is protected against inductive spikes from selector magnets on the line, and should tolerate currents from <20mA to over 100mA. The loop current is sensed non-inductively by a 150 ohm, 2 watt resistor in series with the loop, which provides current to the input side of an opto-isolator. The output side is switched by another optical isolator with an on resistance around 34 ohms. Both input and output can be connected in any polarity. The device has separate connections for input and output, so it can be used in a full-duplex application with two separate loops, but for half duplex operation normally the two connector blocks would be jumpered in series. (they are also completely electrically isolated from each other.)
-==Modification==
+==Modification and firmware updates==
 The controller is an Atmel atmega32u2 with a USB DFU-class bootloader installed via which the firmware can be updated or replaced.  To activate the bootloader, briefly short the two bare pads on the board marked "RST" - the orange LED will go out, and the green LED will blink slowly. The host computer will see the USB serial device disappear and be replaced with one called "Atmel DFU". You can read and program the chip using Atmel's FLIP software[http://www.atmel.com/tools/FLIP.aspx] on most platforms, and the commandline tool "dfu-programmer" on Linux and Mac OSX. On windows you will also need a driver for it, which is provided in the FLIP download; all other OS's don't require any driver. To exit the bootloader, issue a DFU reset command or just power cycle the board.

← Older revision		Revision as of 07:18, 26 April 2016
Line 1:		Line 1:
−	This is a compact USB to teletype current loop interface on a 1.6 by 1.4 inch pcb. It connects to a computer running Windows, Mac OSX, Linux, Android, or probably anything else via a USB Mini-B connector, and presents itself as a USB serial port, while the other end connects directly in series with a teletype loop. Data is relayed bidirectionally between the two. It does not provide loop current itself, so a loop power supply with fuse is needed if not already present. Download the [[Media:usbtty-instructions.pdf\|instruction sheet]] or the windows INF file[http://~~github~~.com/~~epvuc/usb-tty~~].	+	This is a compact USB to teletype current loop interface on a 1.6 by 1.4 inch pcb. It connects to a computer running Windows, Mac OSX, Linux, Android, or probably anything else via a USB Mini-B connector, and presents itself as a USB serial port, while the other end connects directly in series with a teletype loop. Data is relayed bidirectionally between the two. It does not provide loop current itself, so a loop power supply with fuse is needed if not already present. Download the [[Media:usbtty-instructions.pdf\|instruction sheet]] or the windows INF file[http://teletweety.com/usbtty_adapter.inf].

	[[File:loop-adapter3.jpg\|450px]]		[[File:loop-adapter3.jpg\|450px]]