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Fortress Technologies An E1T Timepiece Manual

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Fortress - An E1T Timepiece
Six Miniature CRTs In Action
Page 1
Version 1.0
Copyright Grahame Marsh/Nick Stock 2019

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  • Page 1 Fortress - An E1T Timepiece Six Miniature CRTs In Action Page 1 Version 1.0 Copyright Grahame Marsh/Nick Stock 2019...
  • Page 2 Fortress What is the Fortress? It’s the culmination of an awful lot of work by two like-minded individuals who like to tinker with vintage display technologies and turn them into functional and unusual time-pieces. This clock is somewhat unique in many respects. It is, to our knowledge, the only ‘commercial’...
  • Page 3 another vintage display technology, the cathode ray gun into a discrete counting device. The E1T uses a cathode ray and some neat tricks to display a green line in 10 positions, each cunningly numbered from 0 to 9. These were used in early counters (such as the one pictured on the right).
  • Page 4 One of two speakers on the underside of the Fortress Custom 5A PSU for the Fortress Initial Clock Setup and Operation First, you’ll need to find a good spot to place your clock, the best options being somewhere out of direct sunlight as this will washout the E1T displays and the LED highlighting. The clock does have an auto adjustment for the LED intensity based on the ambient light in the room.
  • Page 5 audio on a particular clock face simply press the encoder in and turn clockwise to increase and anti-clockwise to decrease (the volume level will be displayed on the two rightmost E1T tubes). You can also use the IR remote for the same purpose. Clock Customisation One of the core principles embedded in an Open Source device such as Fortress is the ability to customise it by understanding how it ticks .
  • Page 6 Table of Contents Page 7 Quick Start Guide For the impatient in all of us. Pages 8 - 12 Safety Information and Legal Information on how to use the clock safely, warranty information and the Open Source philosophy involved. Pages 13 - 43 Fortress Clock Distribution Faces A list of all the clock ‘faces’...
  • Page 7 Quick Start Guide Impatient huh? Want to just plug this thing in and get on with your life? Here’s the minimum you should consider knowing before enjoying the show. Read the Safety and Legal chapter. Note the do’s and don’ts please. Change your location details on the SD card.

  • Page 8: Safety And Legal

    SAFETY AND LEGAL SAFETY, LEGAL & LICENSE CONSIDERATIONS You know, the fun stuff…. Page 8 Version 1.0 Copyright Grahame Marsh/Nick Stock 2019...

  • Page 9: Safety Statement

    Important Safety Information Annex - Safety and Legal Statements Safety Statement Like all scope clocks, The Fortress uses high voltages in order to operate the cathode ray tube (CRT) inside the E1T tube. You need to respect this and other hazards inherent in these circuits. Caution! The Fortress clock must be correctly earthed (grounded) using only a 3-core mains cable to a correctly earthed mains outlet.
  • Page 10 Legal Statement The Fortress clock is built and documented with an Open Source philosophy in mind. All the source files including circuit diagrams, Eagle board, software and design files are provided under a Creative Commons ShareAlike 4.0 International license. More specifically; You may share, copy and redistribute the material in any medium or format, ii) You may remix, transform and build upon the material presented herein, iii) You MUST give appropriate credit, provide a link to the license and indicate if changes have...
  • Page 11 Atmel Licence The Fortress firmware makes extensive use of the Atmel libraries. The Atmel License (also given in every Atmel library file) is Copyright (c) 2012-2015 Atmel Corporation. All rights reserved. License Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1.
  • Page 12 Permission to use, copy, modify, distribute, and sell this software and its documentation for any purpose is hereby granted without fee, provided that the above copyright notice appear in all copies and that both that the copyright notice and this permission notice and warranty disclaimer appear in supporting documentation, and that the name of the author not be used in advertising or publicity pertaining to distribution of the software without specific, written prior permission.
  • Page 13 Fortress - Clock Distribution Faces The Standard Face Feature Set For the latest Fortress Faces distribution, see the Fortress Face Supplemental on the DropBox Page 13 Version 1.0 Copyright Grahame Marsh/Nick Stock 2019...
  • Page 14 Introduction This manual section describes the clock “faces” that you will find on the supplied SD card (or the standard set you download should you be building the clock yourself). Whilst you can just use these distribution faces and their numbering and arrangement, you are encouraged to rearrange the faces and pick the ones to commonly use yourself.
  • Page 15 My Favourite Clock Face Selection Whilst you can choose yourself how to use the face numbers, I use faces 1 to 9 for my favourites, as the effort to select one of them is therefore minimal. In all cases these faces are duplicates of main grouped clock faces with numbers 100 and above.
  • Page 16 100- Illustrating faces that just show the time with minimal bling All these faces respect the user settings for 12 or 24 hour displays and as such the 10's hours E1T should be blanked when displaying the time from 0 to 9. Face number Nuggle file time01.nug...
  • Page 17 Nuggle file time11.nug Simple time display, respect user format setting. Spin the Description seconds each second then all tubes on each minute roll over Colons Flash green Bling Dim green Chimes None 110 - Illustrating faces that just show the date with minimal bling All of these faces respect the user settings for year, month and day leading zeros and the display order.
  • Page 18 All these faces respect the user settings for year, month and day leading zeros and the display order when showing the date. They also respect the user settings for 12 or 24 hour displays and if the 10's hours E1T should be blanked when displaying the time. Face number Nuggle file dattim01.nug...
  • Page 19 Face number Nuggle file dattim03.nug Time is shown except during Description seconds 40 to 49 when the date is shown Showing time - flash white Colons Showing date - fixed white All tube and downward bling show the same HSV colour. The IR handset* can be used Bling to switch to a hue using keys 0...
  • Page 20 130 - Westminster Quarters Set The Fortress E1T clock has three sets of Westminster Quarters , WAV files including compatible 43 44 tick-tock WAV files. I am reasonably sure that none of these files are the actual sound of the bells used at the palace of Westminster .
  • Page 21 Face number Nuggle file cwest.nug Shows the time as hh:mm:ss using flashing colons, no bling Description and Westminster Quarters file set C Colons Colons flash green each sec. Bling None c-west00.wav, c-west15.wav, c- west30.wav, c-west45.wav, c-wt1.wav, c-wt2.wav, c- wt3.wav, c-wt4.wav, c-wt5.wav, Chimes c-wt6.wav, c-wt7.wav, c- wt8.wav, c-wt9.wav, c-...
  • Page 22 Face number Nuggle file steph.nug Shows the time as hh:mm:ss Description St. Stephen Chimes, ticking, flashing colons, no bling Colons flash green each Colons second Bling none steph00.wav, steph15.wav, Chimes steph30.wav, steph45.wav, stepht.wav, tick01.wav 140 - Ship's bells Face number Nuggle file ships.nug Shows the time as hh:mm:ss...
  • Page 23 150 - Miscellaneous Faces Here are some … strange … clock faces Face number Nuggle file resistor.nug Description Shows the time as hh:mm:ss. Colons Colons flash cyan each second The bling around each tube lights with the corresponding colour to the value shown Bling using the resistor colour code numbers.
  • Page 24 Face number Nuggle file ost01.nug Original Star Trek themed Description clock. Clock shows hh:mm:ss Static purple - the colour of Colons the sky. Two red shirts (security in this case- https://en.wikipedia.org/ wiki/ Redshirt_(stock_character)), two yellow shirts (command, helm), two blue shirts (medical, science) will accompany you to the planet.
  • Page 25 Face number Nuggle file elvis.nug Elvis (https://en.wikipedia.org/ wiki/Elvis_Presley) themed Description clock (quarters and toll). Shows the time as hh:mm:ss. Colons flash gold each Colons second Bling None elvis00.wav, elvis15.wav, Chimes elvis30.wav, elvis45.wav, elvist.wav Face number Nuggle file tng01.nug Star Trek The Next Generation Description themed clock Colons flash white each...
  • Page 26 200 - Complex Faces These faces are where all the previous themes and displays are brought together. So these faces combine use of the E1T tubes, complex bling patterns and colours, and chimes together into single faces. Perhaps not for the faint-hearted. Face number Nuggle file nick01.nug...
  • Page 27 250 - Sequential Faces Face number Nuggle file seq10.nug This is the sequential face calling file. It displays nothing itself but runs a series of other Nuggle face files in sequence. It makes use of NVR variables Description to pass information to the called Nuggle programs.
  • Page 28 300 - Sun Information The Fortress E1T clock firmware contains calculations of the time of sunrise and sunset for the geo-location set by the user in the locale.ini file . The calculation is reasonably accurate but since it depends on some simplifications, the results are only displayed to hours and minutes. Displaying seconds would be misleading.
  • Page 29 Face number Nuggle file sunrise.nug Shows the sunrise today as hh:mm using tubes 0 to 3. Tubes 4 and 5 remain blank. There are conditions where Description the sun might not rise and so all the tubes will remain blank and the bling (see below) is used to indicate them.
  • Page 30 350 - Hardware games Face number Nuggle file pir.nug This is a game. You select the face away from the clock and then walk towards it. Each Description time the PIR sensor sees you it will increment the count on the tubes, flash the bling and make a noise...
  • Page 31 Face number Nuggle file runner.nug The leftmost tube counts 0 to 9 with the remain tubes blanked, then the next tubes Description counts 0 to 9 and so on until 9 is reached on the rightmost tube. The cycle then repeats. Colons None A green flash follows the lit...
  • Page 32 Face number Nuggle file larson.nug A bling Larson (https:// en.wikipedia.org/wiki/ Glen_A._Larson) scanner from a Cylon (https:// en.wikipedia.org/wiki/ Description Cylon_(Battlestar_Galactica)) or Kitt (https:// en.wikipedia.org/wiki/KITT). The E1T tubes are not used and remain off. Used as part of the bling Colons cycle. The bling is pulsed with a red Bling fading light sweeping from...
  • Page 33 900 - Technical stuff These faces show various internal settings for the clock. They are not really intended as day-to- day displays but can be used to check a limited number of values without plugging in the USB console connection. Face number Nuggle file hardware.nug...
  • Page 34 Face number Nuggle file latitude.nug Shows the clock latitude in the form DD.dd where DD is the latitude in degrees as a Description positive number (the sign will be shown using the left colon) and dd is the fraction. This value is read from locale.ini.
  • Page 35 Face number Nuggle file elevatn.nug Shows the clock elevation using the user preferred units Description (metres or feet). The value and preferred units are read from locale.ini. Colons None Is lit around and under all Bling tubes. Chimes None Face number Nuggle file chiptemp.nug Show the internal SAM3X8C...
  • Page 36 Face number Nuggle file wifi.nug Shows the status of the WiFi connection using the bling Description and colons. The E1T tubes are not used. No WiFi module installed - both colons are blue. WiFi installed - the left colon shows the WiFi connection status: Colons red not connected, green...
  • Page 37 Face number Nuggle file paired.nug Shows the IR Handset pairing status. If the pairing is disabled or forced to be enabled then the tubes are not used. If pairing is enabled Description then the pairing number is shown. The status is only shown when the face is first displayed.
  • Page 38 For example: You live in San Diego, CA. It is summer time. You want to set the clock to 12:35:00 local time. San Diego uses daylight saving so the local time without daylight saving is 11:35:00. San Diego is Pacific Time which is UTC-8 hours, therefore the current time in UTC is +8 hours so is 19:35:00 and this value should be entered into the clock.
  • Page 39 Only the two least significant digits of the year can be changed. The most significant digits are always 20. Thus the date can only be changed within the range 2000 to 2099 . Datetime.nug takes over most of the IR handset keys. When the Nuggle program is run the tubes will display the current UTC day, month and year from the RTC.
  • Page 40 Face number Nuggle file reset.nug After a count down period of ten seconds the clock will attempt to hard reset. The E1T Description tubes show the count down. The bling shows the last six seconds and the chimes the last four seconds. Colons Not used Initially the tube bling is all...
  • Page 41 1000 - Nuggle Tests These test aspects of the Nuggle firmware in C. It is expected that these are run using the console as many send reports. These tests are simple and are not considered comprehensive or stressful. Description Face Number Filename 1000 t_hello.nug...
  • Page 42 2000 - Nuggle Cookbook Examples The Nuggle Cookbook is in preparation at this time so this section is far from complete. 2100 - Illustrating Sequentially Addressed Faces Clock faces can be displayed for a period of time and then replaced with an alternative. A chain of faces can be built and displayed sequentially.
  • Page 43 Annex A - NVR Variable Usage Values can be stored in NVR to pass information between Nuggle programs and to preserve data when the clock is reset or restarted. NVR Index Face counter, incremented each time a new face is shown by the sequential counter Sequential calling Nuggle program to return to Period in seconds to show the sequentially called file for Used in t_face.nug to test the Nuggle Face procedure...
  • Page 44 Fortress E1T Operations Guide Everything you wanted to know but daren’t ask…. Page 44 Version 1.0 Copyright Grahame Marsh/Nick Stock 2019...
  • Page 45 Introduction This section describes most of the technical aspects of the Fortress E1T Clock design and its operation. It also covers the basics on how to modify aspects of the clock to suit your tastes. Subjects covered: • The main board option jumpers •...
  • Page 46 Main Board Option Jumpers There are eight jumpers on the main board (component X3 near to the backup battery/super- cap) which can select operating options that need to be decided as the clock is initially starting up. Jumpers must only be fitted or removed when the clock is switched off. The options jumpers are numbered 1 to 8 and control the following: 1.
  • Page 47 Console Connection The console is a simple text-based user interface that allows many clock settings to be adjusted and tested. It is an imported debug tool when writing Nuggle programs. The console hardware is also the SAM3X8C programmer. The SAM3X8C programmer The programmer is plugged into the Fortress E1T clock processor plug-in board using a 6- way ribbon cable and IDC connector.
  • Page 48 console to something like 115200, 8, N, 1 with no flow control. When power is applied to the Fortress E1T clock and the reset button on the clock pressed briefly you should see a simple welcome message . Something like: Setting up the Serial Port in Tera Term Or a much longer one if the “verbose”...
  • Page 49 Console Menus The console menus are a simple, text-based system to allow commands to be entered that can run Nuggle programs, alter clock settings, interrogate system settings etc. All commands are four letter keywords like DATG and SYSR. The first three letters are the name (or noun) of the part of the clock that the command acts on and the last letter is the action (or verb) that is to take place.

  • Page 50: Command Entry

    For example: DATG “get” the current date VERR “report” hardware/firmware version and build information SYSU "use" the system - a parameter sets how LDR? “help”, LDR help information LEDK “kill”, turn all bling LEDs off Some commands have mandatory parameters, for example: TIMS 12:00:00 “set”...
  • Page 51 BEP? BEeP command help message Play a beep c = channel 1 = right BEPS c, f, d 2 = left 3 = both f = frequency 30 .. 5000 Hz d = duration 10 .. 5000 mS BEPU n Play a pre-defined beep sequence 0 ..
  • Page 52 DATG Get the current UTC date DATR Report the date for UTC, ISO and local. Set the UTC date DATS yyyy-mm-dd example: dats 2018-1-14 DATU Perform a synchronisation with the plug-in WiFi or GPS module See also the TIMe command. E1T display tests The six E1T tubes can be addressed.
  • Page 53 FACe Command Help Message FACG Return the index number of the current displayed face FACL Reload the face index table from [faces] section in nuggle.ini FACR Clock face report FACS n Change the displayed face to face index number n GPS plug-in module tests These command require the GPS module to be installed (obviously).
  • Page 54 LED bling-bling controls Try different bling LED module brightness and colour controls. Brightness can be static or dynamic. Colours can be entered as RGB or HSV formats. See also the TheMe commands LED? LED bling-bling help message set the bling brightness setting to static level fxd = 1 ..
  • Page 55 LOCale reports Report locale information such as DST, time zone, geolocation and user preferred formats. LOC? LOCale report help message Locale reports: n = 0 - DST rules showing the selected rule if any LOCR n n = 1 - time zones showing the selected time zone n = 2 - geolocation information read from the SD card n = 3 - user preferred date and time formatting settings NUGgle programs...
  • Page 56 digital OUTput controls Get, set and report on a limited range digital IO pins. OUT? Digital OUTput help message Get the current setting of digital output n n = 2 - pin 2 on header X1 OUTG n n = 3 - pin 3 on header X1 n = 6 - 6.3V heater enable...
  • Page 57 SYStem reports and actions A variety of system reports and actions to invoke. SYS? SYStem help message System report n n = 0 - memory use n = 1 - SAM3X8C chip identification n = 2 - SAM3X8C core temperature °C SYSR n n = 3 - task system status n = 4 - demonstrate floating point errors...
  • Page 58 system VARiable report and interrogation Nuggle programs can access system information using so-called system variables. These values are variable in that the system will change them but the user cannot (at least within a Nuggle program). They are therefore considered read-only. VAR? System VARiable help message Get the current value of a system variable, in both decimal and hexadecimal...
  • Page 59 Programming the SAM3X8C This is a simplified and shortened guide to programming the SAM3X8C. For a complete description see the Sgitheach SAM3X8C Programmer/Serial Console Board manual. As a programmer the programmer/serial console board uses the BOSSA programming utility to talk to the boot-loader in the SAM3X8C.
  • Page 60 SD Card Access, Folders and Files To inspect or change the SD card contents it can either be removed and plugged into a reader or a USB cable can be plugged into the SAM3X8C board and your PC, then the SD card will appear as a “USB Drive”...
  • Page 61 Daylight saving time rules for the various countries that use DST. dst.ini Should not require editing. If a rule needs to be changed then expect a new version of the file from me. The help messages used by the menu console. So when you enter ADC? for help.txt example, the help text is read from this file.
  • Page 62 Adding or changing Chime WAV files Introduction The Fortress E1T Clock uses WAV files to sound chimes and make other noises. The clock hardware uses the two 12 bit Digital to Analogue Convertor (DAC) outputs from the SAM3X8C each passed through Low Pass Filter (LPF) to an audio amplifier feeding a small speaker. Input WAV file requirements The input file requirements are: •...
  • Page 63 The converted data is saved to a directory called CHIMES in the root directory of the SD card. For a given WAV file, two files with the same name are created with extensions CHM containing the DAC ready data and HDR containing set up data such as the sample rate and information about the original data, such if it was mono or stereo.
  • Page 64 Adding or changing Nuggle programs Nuggle is a simple programming language used by Sgitheach clocks. It describes how the display devices such as VFD, CRT, Dekatron or E1T tubes, bling LEDs, chime system will be used. The Fortress E1T clock comes with a large number of Nuggle files available so you can review these to see actual Nuggle source text examples.
  • Page 65 9. Compiling the Sgitheach SAM3X8C Clock Firmware for the Fortress E1T Clock Introduction These notes are to help you install the final release 1 firmware source code and how to compile it. The output of this process are binary files that are identical to the binary files available on the Dropbox.
  • Page 66 Compiler Optimisation - change the level to Optimise most (-O3) • Compiler Optimisation - add, if missing, -fdata-sections -fstack-protector-all • Compiler Symbols - if present, delete the printf=iprintf and scanf=iscanf symbols • Compiler Symbols - add, if missing, BOARD=USER_BOARD and delete any other •...
  • Page 67 10. InfraRed Remote Control The IR handset is used to remotely and conveniently change the way the Fortress E1T clock is operating. The keystrokes on the IR handset can be overridden by certain Nuggle face scripts that are running. The description here is the default use of the IR keys.
  • Page 68 However, you can use any number you wish in the range 1 to 999999. Obviously if you have two Sgitheach clocks of the same type then you'll need to give them different numbers. To pair the clock, you start by pressing the '>||' key. All Sgitheach clocks respond to this key press and enter the pair number entry mode.
  • Page 69 11. Troubleshooting Guide Introduction Given the complexity of the Fortress E1T Clock it is difficult to give a completely comprehensive guide to the faults that might occur and how to find them. I would expect 99.9% of first time faults to be soldering problems, either a poor solder joint or a bridge between adjacent conductors.
  • Page 70 Additionally, the project Eagle files are contained on the project Dropbox. These files can be opened using the free Eagle version. The main board will operate happily without the display board plugged in. Therefore, you can detach the display board and flip the main board over so you have easy access to its component side.
  • Page 71 E1T Static Voltages These voltages were measured with no Nuggle program running and an E1T glowing in position '0'. Under these conditions the HT switch transistors are conducting, the step pulse transistor is off and the reset transistor is conducting. Point Reference Measured...
  • Page 72 E1T Circuit Waveforms The following oscilloscope images were captured using a Rigol DS1052E. Not a particularly high specification oscilloscope but good enough for this task. An ordinary x1 probe was used with DC coupling unless otherwise stated. In all cases the E1T was spinning at 100mS between step pulses using the console E1TC command.
  • Page 73 2. Step pulse after the drive transistors. This is the voltage on the collector of the PNP step driver transistor. It is about 18V in amplitude and has about a 1mS decay period. 3. Step deflection pulse. A x100 probe was used with DC coupling.
  • Page 74 4. Reset pulse. This is a connection from the SAM3X8C, a pulse 3.3V low and 10mS long. 5. Res et pulse trans ist o r collector. 6. E1T Grid. This is the voltage on the E1T grid. The strong negative pulse to -13V cuts off the electron flow through the tube causing it to reset to position 0 when the current flow is re- established.
  • Page 75 7. E1T Deflection Plate x'' and anode 2. A x100 probe was used with DC coupling. In this image the cyan trace (channel 2) shows the position of the ground (0V). A few observations: The high pulse at the start of the cycle (below the T symbol) reaches nearly 300V or the +HT supply.
  • Page 76 Dim Glows Another occasional fault is that the selected position is not very bright. This tube has a remarkably dim '9'. It is still visible and brighter than the '8' and '7' additional lines. Therefore I use this tube in one of the 10's positions, for example 10's of hours, so the '9' is not used much.
  • Page 77 Miss-Counting I have one tube that counts 0,2,3,4,5,6,7,8,9,9,0,2 … Looking at the x' and anode 2 voltage you see: You can see the step from the '0' position to the '2' position is twice the height of the other steps. Double stepping like this does not normally occur until the step pulse voltage is over 20V.
  • Page 78 Offset Decals Occasionally, the decal has not been applied exactly in alignment with the glow positions. Here the glow position is a few mm to the right of the centre of the figure '2'. Perhaps I'm being a bit picky... An Indicator of Tube Age? Apart from obvious signs of age such a dirt, grime or a damaged decal, there is little to indicate how well used a tube...
  • Page 79 Fortress - How It Works Board Schematics and Function Page 79 Version 1.0 Copyright Grahame Marsh/Nick Stock 2019...
  • Page 80 Introduction The Fortress E1T Clock schematic diagrams are spread across over a dozen pages and many of the individual pages have several subsystems on them. This Fortress manual section is a walk through of the schematic drawings. Subsystems The clock consist of the following subsystems: •...
  • Page 81 1.0 SAM3X8C Microcontroller Plug-in Arduino fans may recognise this number in relation to the Arduino Due as it uses the SAM3X8E micro-controller. The SAM3X8C is a smaller sibling in a 100 pin package and has less I/O pins but internally it is more or less the same, has the same flash memory (512K) and runs at 84MHz clock speed.
  • Page 82 1.1 SAM3X8C schematic Page 82 Version 1.0 Copyright Grahame Marsh/Nick Stock 2019...
  • Page 83 1.2 Battery Backup 1.3 Analogue Decoupling 1.4 PLL Decoupling 1.5 Core Decoupling 1.6 IO Decoupling 1.7 UTMI Decoupling 1.8 3.3V IN Decoupling 1.9 3.3V OUT Page 83 Version 1.0 Copyright Grahame Marsh/Nick Stock 2019...
  • Page 84 1.10 System Oscillator 12MHz Crystal 1.12 Reset 1.11 RTC Oscillator Options •Fit C28 and Y3 to use the external oscillator • Fit C29, C30 and Y1 to use an external crystal 1.13 Programmer Socket The connections made here are for the Sgitheach SAM3X8C programmer only.
  • Page 85 1.14 USB Socket The USB socket cannot be used to power the plugin board. The board can only be powered using connections to the headers. Page 85 Version 1.0 Copyright Grahame Marsh/Nick Stock 2019...
  • Page 86 1.15 Header Connectors To conserve space 2mm spaced headers are used instead of the more usual 2.54mm spaced headers. Page 86 Version 1.0 Copyright Grahame Marsh/Nick Stock 2019...
  • Page 87 1.16 Miscellaneous Connectors 1.17 3.3V PSU This regulator can be used to supply power but care must be taken not overload it. 2.0 SAM3X8C Programmer • 5V power indicator • 3.3V power indicator • Reset circuit • 16MHz clock oscillator •...
  • Page 88 • MEGA16U2 ISP socket • Connection to SAM • Indicator LEDs for Reset, Erase, data Tx and data Rx • Level shifter for Tx data • Drivers for SAM Reset and Erase lines • Optional control switches This is more or less the programmer used on the Arduino Due (and maybe other Arduino versions as well).
  • Page 89 3.0 Fortress Main Board The main board carries all of the clock electronics except the E1T tubes and their drivers. The E1T display board and main board are designed to mount back to back with inter-connectors to pass signals and power between the two boards. 3.1 SAM3X8C Plug In 3.2 Back up power (A super cap or a Li cell provide back up power;...
  • Page 90 3.3 Hardware Version Sense A unique resistor potential divider allows the firmware to detect the hardware version. 3.4 Storage - SD Card This is a native SD Card interface and not a slow SPI based one. It transfers 4 bits of data per clock cycle (the SPI transfers 1 bit) and will clock at 50MHz with a Class 10 SD Card (SPI will clock Chapter 37 SAM3X8C data sheet Page 90...
  • Page 91 at 10MHz). So is roughly 20 times faster. I/O pins are used to detect that a card is plugged in and whether it is write protected or not. 3.5 Storage - Non-Volatile RAM (NVR) The SAM3X8C has no internal EEPROM so some TWI (I2C) NVR is provided to hold data when the clock is switched off and can also be used to pass information between clock faces.
  • Page 92 3.6 Reset and Power Supervisor This handles low 5V detection causing the SAM3X8C to reset. Reset can also be accomplished by the switch or the SAM by pulling the gate of Q1 high. 3.7 Option Jumpers The firmware uses these jumper to configure the clock without having to use any more complex hardware like the SD card.
  • Page 93 3.8 Plug In Module Socket Optional add-ons include a GPS receiver or a WiFi adapter to allow the clock to automatically set the date and time. See below. Page 93 Version 1.0 Copyright Grahame Marsh/Nick Stock 2019...

  • Page 94: Audio Amplifiers

    3.9 Audio Amplifiers The stereo audio amplifier each take signals from the SAM3X8C digital to analogue (DAC) convertor outputs and from pulse width modulated (PWM) I/O pins. Four signals in total. The DAC output are used to play WAV files from the SD card and the PWM output can make a wide www.ti.com/lit/ds/symlink/lm48100q-q1.pdf Page 94 Version 1.0...
  • Page 95 variety of simple beep-beep noises. The volume controls are set using the TWI bus and the amplifier chips can report error conditions back to the SAM 3X8C. 3.10 Front Panel Controls A short ribbon cable provides power to the controls and returns their signals to the SAM3X8C.
  • Page 96 3.11 Bling-Bling RGB LED Modules The Fortress clock has a total of thirty two RGB LED modules. These devices are connected to Channel 0 of the SPI bus. The devices used require a 5V supply and signals so two buffers are used to select the SPI channel and act as 3.3V to 5V level shifters.
  • Page 97 The main board has six modules in total and these are arranged to fire downwards to illuminate underneath the case. The outputs from Z10, the 6th module, are taken to connectors to the display board. In addition to the decoupling capacitor across each module, some energy storage is allowed for along the 5V supply traces on the PCB.
  • Page 98 3.12 +300V HT PSU The E1T tubes require +300V to operate. This power supply is a simple flyback convertor using a custom transformer. It is a very robust supply. Q2 acts as a level convertor and makes the logic positive: a 3.3V input is required to switch the convertor on.
  • Page 99 3.13 6.3V Heater PSU The E1T tube heaters operate at 6.3V 300mA, therefore this switched mode down convertor will provide about 2A. The heater PSU can be switched on by the SAM3X8C via the buffer/level convertor IC10. The convertor has a soft start feature which is configured to take roughly 10 seconds to increase the output voltage from 0V to 6.3V.
  • Page 100 3.14 5V PSU and 3.3V PSU This starts with the 12V DC input from the remote power supply. The switch mode down converter is almost the same as the 6.3V heater PSU. Differences are that it has no on/ off function but remains on all the time. The feedback potential divider has different value of course and the compensation network is slightly different.
  • Page 101 3.15 Inter-board Connectors These transfer +300V, +5V and 6.3V to the display board. These transfer the LED module serial data and clock signals and return the LDR resistance to ground. Page 101 Version 1.0 Copyright Grahame Marsh/Nick Stock 2019...
  • Page 102 Each E1T requires three signal lines, one to switch the 300V supply, one to reset the tube to zero and one to step the tube by one. Therefore eighteen control lines are required which are transferred using the three 2x3 headers. Finally, the SPI bus is made available for expansion purposes.
  • Page 103 3.16 WiFi Plug In This uses an ESP32-BIT module. Serial data is transferred to the SAM3X8C. The module can be reset using Q1. Programming the ESP32 is accomplished using the SAM programmer and fitting the program jumper. Page 103 Version 1.0 Copyright Grahame Marsh/Nick Stock 2019...
  • Page 104 3.17 GPS Plug In Serial data as NMEA statements are transferred from the GPS module to the SAM3X8C. The use of an external active antenna is selected using R4, R5 and R6. Page 104 Version 1.0 Copyright Grahame Marsh/Nick Stock 2019...
  • Page 105 4.0 Display Board 4.1 E1T Drivers The six E1T tubes have identical drivers. There are three 2x3 headers that transfer the signals from the SAM3X8C. The schematic below shows Dieter Wächter's step pulse circuit. By omitting a few components, changing a few and decreasing the step voltage then the same PCB can use the step pulse circuit by Ron Dekker .
  • Page 106 4.2 +12V Regulator 4.3 +30V Regulator 4.4 +15V/18V Regulator 4.5 +156V Regulator 4.6 Bling Data and Clock, LDR Connector Page 106 Version 1.0 Copyright Grahame Marsh/Nick Stock 2019...
  • Page 107 4 . 7 B l i n g - B l i n g L E D R G B Modules A total of twenty six LED modules are used; just two are shown here. The E1T tubes are lit with four apiece and the remaining two are used as colon separators.
  • Page 108 Page 108 Version 1.0 Copyright Grahame Marsh/Nick Stock 2019...
  • Page 109 Page 109 Version 1.0 Copyright Grahame Marsh/Nick Stock 2019...
  • Page 110 Page 110 Version 1.0 Copyright Grahame Marsh/Nick Stock 2019...
  • Page 111 E1T Tube - How 1T Works A Miniature CRT In Action Get it? Ha ha ha.. Page 111 Version 1.0 Copyright Grahame Marsh/Nick Stock 2019...
  • Page 112 An Extract From Dance’s “Electronic Counting Circuits” Chapter 5 - E1T Decade Counting Circuits The principle of operation of the Mullard/Philips E1T decade counter tube is fundamentally different from that of all other types of counting tube. The E1T is a high vacuum tube which has been especially designed for counting purposes;...
  • Page 113 symbol for the tube, as used in circuits, is shown in Fig. 5.3 with the connections to the B12A base. Some of the less important electrodes which have no external connection are not shown in this symbol. Sometimes g and g are also omitted from the symbol.
  • Page 114 5.1.2 - Ribbon Shaped Electron Beams In tubes such as the E1T in which the beam is deflected only in one plane, a ribbon shaped electron beam of relatively large cross sectional area can be used (since the resolution in one plane is unimportant), but in normal cathode ray tubes a very small circular beam must be used to obtain good resolution in two dimensions.
  • Page 115 5.3 - BEAM STABILITY The basic type of circuit used to supply voltages to the tube is shown in Fig. 5.7. The anode resistor, R normally has a value of 1MΩ. The straight line in Fig. 5.6 is the load line for this value of resistor.
  • Page 116 At these unstable points the anode current decreases with increasing anode voltage, thus giving a negative resistance effect over this portion of the curve. The criterion of stability for any operating point in Fig. 5.6 is that the anode current of the E1T must increase as the anode voltage increases.
  • Page 117 longer than the counting process it-self and sets a limit to the maximum counting speed. A suitable pulse for feeding into the x' electrode of the E1T is shown in Fig. 5.9. The slope of the leading edge of the pulse should not be less than 2 x 10 V/sec and that of the trailing edge should not be greater than 1.2 x 10...
  • Page 118 amplitude of at least 24V so that it is large enough to completely cut off the electron beam. The main anode current falls and therefore the main anode and x" electrode potential rises. The change of the x" electrode potential causes the beam to be deflected towards it so that 'zero' is indicated.
  • Page 119 If t is the total time taken for the potential across the capacitance C to reach the value V (0) from an initial value of zero, − V −t 2 R a2 C Dividing (2) by (1): − V −t 2 − t 1 R a2 C −...
  • Page 120 E1T Data Sheet Page 120 Version 1.0 Copyright Grahame Marsh/Nick Stock 2019...
  • Page 121 Fortress - Nuggle for the E1T Writing code for your Fortress Clock Page 121 Version 1.0 Copyright Grahame Marsh/Nick Stock 2019...
  • Page 122 Introduction Nuggle supplementary documentation for the Fortress E1T Clock Basic Language Elements Reserved Words Reserved words that are new or have a specific meaning for the Fortress E1T clock version of Nuggle are: Clear, Display, E1T, Flyback, GPIO, Heater, Saver, WriteE1T, WriteDisplay Program Heading and Program Block System Defined Number Variables There are no additional system defined number variables for the Fortress E1T Clock.
  • Page 123 GPIO Syntax: GPIO (pin) Returns the boolean value of the GPIO pin as follows: Location SAM3X8C port and pin Pin 2 on connector X1 Port A Pin 10 Pin 3 on connector X1 Port A Pin 11 Procedures Display Syntax: Display tube, value This is a synonym for the Fortress E1T procedure and function and can be used where possible to write display independent Nuggle.
  • Page 124 Saver Syntax: Saver value Specify the “screen saver” display to be used with the current clock face overriding the default saver. The argument value is the index of a Nuggle program defined in nuggle.ini. Example: Saver 402 WriteDisplay Syntax: WriteDisplay Str [, …] This is a synonym for the Fortress WriteE1T procedure and can be used where possible to write display independent Nuggle.
  • Page 125 Event Default Actions Fortress E1T clock has the following event default actions: Event Label: Default Action: If the clock is asleep (any stage) it wakes up. event_encoder: Clock face or sound volume changed. See below. If the clock is asleep (any stage) it wakes up. event_ir: See below for other default functions.
  • Page 126 Default IR Handset Events The IR Handset has default actions for all of the buttons. You can change the volume of the chimes and the beeps, set the pairing number, select a clock face directly or by scrolling through available faces and finally enquire what face number is currently displayed.
  • Page 127 Wake up from being asleep During the wake up cycle - fully asleep to fully awake - the following states are passed through and actions are taken. The timings of some stages are adjustable in the [sleep] section of system.ini on the SD card. arg_sleep Constant Actions...
  • Page 128 If you want to see these processes in action then use the sleep debug system at level 3 (set in system.ini) or write a Nuggle program to do so. Sleep states, 0, 1, 10, 13 and 16 are used internally and are not sent to the event handler. If the Default action takes place at step 5 then the screen saver Nuggle program is run and your program looses control.
  • Page 129 Annex A System Variables There are no additional system variables. Annex C Fatal Error Messages There are no additional fatal error messages. Annex D Bling LED Numbering These images show the position numbers of the bling LED modules as seen from the board silkscreen side.