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Fred Bayer | Rosenheim | Germany | (+49) 8031 86550 | fred@bayerf.de

F4LW user manual

On power on, F4LW is displayed briefly, after that the software version V15E (or V15G for the German version). The F4LW has four major modes which can be selected via the colored buttons on the remote control.

Word mode (red button)

Various 4-letter words are displayed, the speed buttons control the duration one word is displayed. Use the numeric buttons to select from these options:

ButtonFunctionExample
Vocabulary
1 Select random words from the dictionary in EEPROM. word mode 1
2 Try to build random word chains from the dictionary in EEPROM. Each word differs by one character from the previous one. Repeating words is possibly avoided, but if there's no way out from a dead end, **** is displayed and a new starting word from the dictionary is chosen. word mode 2
3 Select random pseudo-words by choosing independent characters for each tube. This mode emulates the 70ies "word" generation scheme. word mode 3
Character case
4 Selects all upper case. That's what B7971 tubes are made for. word mode 4
5 Selects title case, the first char is upper case, the rest is lower case. word mode 5
6 Selects all lower case. Some lower case chars look good, others fair and a few quite ugly. But that's the display technology of the 70ies. Nobody expected to use lower case at this time ;-) word mode 6
Animations
7 Selects dropping down animation. word mode 7
8 Selects rotating clock face animation. word mode 8
9 Selects random segment animation. word mode 9
0 No animation, words appear at once. word mode 0
Misc.
Menu Display the EEPROM tag briefly rom tag

The character case selected in this mode also influences the case of prompts in other modes. However, case in terminal or message mode is not affected.

Uploading EEPROM contents

Pressing the hardware button on the F4LW in word mode starts uploading the EEPROM via RS232. >UW< is displayed to indicate that F4LW is waiting for data from the PC. Start the Python program uploadROM.py to transfer the memory image. A count down is displayed indicating the number of 64 byte blocks remaining to be uploaded. When finished, OK is displayed briefly and word generation starts. If the EEPROM contents are invalid, ROM? is displayed and only vocabulary mode 3 is enabled. It takes about 55s to upload a 62k memory image.

Creating EEPROM image from a word list

The Python program makeROM.py reads standard text files containing one word per line, filters the 4 letter words, constructs transition tables for word chains, and creates the memory image to be uploaded. A 4-letter EEPROM tag must be specified, too. My favorite word list 5desk.txt contains 2731 four-letter words, 21644 word chain transitions and compiles to the 62k image mentioned above.

An easier way is using F4LWGui.

Clock mode (green button)

The real-time clock is the only timebase used by F4LW, so don't expect too much accuracy. Currently there's no way to set the clock on the F4LW itself, you must use the RS232 to set it, but you can synchronize the RTC to the nearest minute manually.

ButtonFunctionExample
Single displays
1 Displays hours and minutes, 24h mode only. HH:MM
2 Displays minutes and seconds. MM:SS
3 Displays day and month. DDMM
4 Displays day of week as 3 letter abbreviation. The rightmost tube displays *, if daylight-saving time is active. DAYS
5 Displays 4 digit year. YEAR
6 Displays 8 different images representing the moon phase. MOON
7 Displays the sunrise time for the current day. The 2 left-most cursor segments are always on in this mode. RISE
8 Displays the sunset time for the current day. The 2 right-most cursor segments are always on in this mode. SSET
Cycling displays
9 Cycle thru all 8 displays above. The duration of each display can be adjusted with the speed buttons. large cycle
0 Cycle thru the first 4 displays above. The duration of each display can be adjusted with the speed buttons. small cycle
Misc.
Menu Toggles seconds display via the cursor segments. When active, the cursor segments sweep left to right and back every second. seconds cursor
-/-- Toggles between daylight-saving and standard time. Current time and sunrise/sunset times are adjusted accordingly. toggle DST
Enter In clock synchronization mode, time is set to the nearest minute. clock sync

Setting the clock

Until the clock is set, RTC? is displayed. Pressing the hardware button on the F4LW in clock mode sets the real-time clock of the F4LW via RS232. >SC< is displayed to indicate that F4LW is waiting for the clock data from the PC. Start the Python program setclock.py latitude longitude to calculate sun rise/set times for your location and upload the PC's current time and date. When finished, OK is displayed briefly and clock display starts.

An easier way is using F4LWGui.

Pressing the hardware button in mode 2 (minutes and seconds) enters synchronization mode, which is indicated by all 4 cursor segments lit. Press Enter on the remote control to adjust the RTC's time to the nearest minute and set seconds to zero. This way you can compensate for small inaccuracies of the RTC without having to connect F4LW to a computer.

Terminal mode (yellow button)

In this mode characters received via the RS232 interface are displayed (shifted into the display from the right) Buttons pressed on the remote control are converted into characters (translation table see keymap.inc) and sent to the PC, where arbitrary functionality can be implemented. Have a look at the samples, where a simple 5-function pocket calculator is implemented in just 70 lines of Python.

The speed and brightness control buttons are disabled in this mode, they are also sent to the PC.

Message mode (blue button)

Upto 10 messages (4 chars each) can be selected to be displayed and edited via the remote control. Message texts are stored in the non-volatile RAM of the real-time clock. Press the numeric buttons 0-9 to select a message, or press the Menu button to toggle blinking the current message. To edit a message, press Enter on the remote control.

Uploading messages

Pressing the hardware button on the F4LW in message mode starts uploading messages to the F4LW via RS232. >UM< is displayed to indicate that F4LW is waiting for messages from the PC. Start the Python program uploadMessages.py to transfer them. When finished, OK is displayed briefly and message display starts.

An easier way is using F4LWGui.

Message edit mode

The current tube to be edited is indicated by the cursor segment.

ButtonFunctionExample
Cursor left Move the cursor to the left (cycling) Cursor left
Cursor right Move the cursor to the right (cycling) Cursor right
Cursor up Change the char to the following in ASCII order Char increment
Cursor down Change the char to the previous in ASCII order Char decrement
Numeric buttons Enter a letter, similar to SMS entry on a mobile phone. E.g., pressing 8 cycles thru the chars T, U, V, and 8. There may be additional characters for some keys, too. SMS entry
-/-- Toggle upper/lower case. Toggle case
Enter Exit edit mode and store message.
Back Abort edit mode without storing.

Remote control test mode

To get into this mode, press the hardware button during the power-on display. Now every RC-5 code received is displayed in hexadecimal as RCxx. Write down the codes to adapt F4LW to your remote control and edit rc5codes.inc and keymap.inc accordingly.

This mode can only be left by powering off the F4LW, since the colored buttons display their codes but don't switch modes.

Other buttons

Off

Turns all tubes off. To reactive F4LW, press one of the colored buttons to go to the respective major mode.

Volume +/-

Adjust the display brightness from 0 to 6. The brightness is displayed briefly as BRnn.

Program +/-

Adjust the display speed from 0 to 50. The speed is displayed briefly as SPnn. The speed value is approximately the delay in units of 0.1 seconds, so Speed 0 is fastest and Speed 50 holds the display for about 5 seconds.

Summary of F4LW system messages

MessageCause
BRnn Display brightness has been set to nn.
F4LW Hello world, it's me. :-) The first message on power-up.
MSGx When switching to Message mode, no messages have been entered yet. Either press the hardware button and start the Python program uploadMessages.py, or enter messages via the remote control as described here.
OK Upload has been successfull.
OVER Overflow when converting a 16 bit number to decimal (>9999). You should never see this message.
RCxx Remote control code xx (hexadecimal) has been received.
ROM? The EEPROM is not yet initialized or an improper file has been uploaded. Press the hardware button and start the program uploadROM.py to upload a word list ROM file.
RTC? The real-time clock is not yet initialized or was disconnected from the backup battery. Press the hardware button and start the program setClock.py to upload the current time.
>SC< After pressing the hardware button in Clock mode, F4LW is now waiting to receive the clock data via RS232. Start setClock.py now.
SER? You switched to Terminal mode but there was no response from the serial interface. Either the cable is not connected or no server program has been started at the host. The server should send some chars on start-up to shift this message out of the display.
SPnn Display speed has been set to nn.
>UM< After pressing the hardware button in Message mode, F4LW is now waiting to receive the messages via RS232. Start uploadMessages.py now.
>UW< After pressing the hardware button in Word mode, F4LW is now waiting to receive the EEPROM contents via RS232. Start uploadROM.py now.
Vnnl The second message after power-up, nn is the software version, l the language (currently E or G).
WRAP When trying to toggle daylight-saving time or synchronizing the clock, the date would change. This is forbidden to simplify software.
Last modification: April 21st 2021, 3:52 p.m. — Page generated April 24th 2021, 3:23 p.m. with Django