Schematic

USB Schematic Rev B1f
(Download PDF for local printing.)

USING the USB CARD

Four main features are enabled by having the USB card installed: REC mode, Flash Bootload, PC Bootload and Real Time Clock Calendar.  These three features are very powerful and will greatly enhance your digital modem experience.

Remember, you must have modem software v3.0 (or later) for these features to work as described ... and you must have firmware "C02" loaded on your USB card.

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REC MODE -- Records QSOs to a USB flash memory device

Insert a USB flash memory device into the modem connector.  Again, that LED may or may not come on.

Type Ctrl-U on the modem keyboard to place the modem into RECORD mode.  You will see “REC” displayed on the right side of the modem display and the LED on the USB port will start blinking rapidly, indicating that it is ready to receive any text that you may type in Tx mode or any text that is coming across the LCD in Rx mode.  (Note:  If the USB card is not in place, or not working, the REC will be shown briefly on the display and a beep will be sounded by the modem to indicate that an error condition is present.)

Assuming things are working (no beep and the LED blinking rapidly), place the modem into Tx mode (press F10) and start typing some text.  You do not need to be connected to your transceiver to try this out.  You will see the text displayed on the modem LCD of course, but it is also being simultaneously written to your USB flash device.  

Type Ctrl-U again to stop the REC mode and you will see the USB port LED stop blinking and remain on continuously.  

Remove the USB device and plug it into your computer.  You will notice a new file on the stick called NUE-PSK.TXT.  If you open this file you will see the text that you typed while in Tx mode, and any other text that might have been displayed while in Rx mode.

As summarized on the Command Reference sheet, two other USB-related features are available to you.  One is that you may specify your own unique filename for the data being recorded to the USB device while plugged into the modem.  Before turning on REC mode (CTRL-U), you may type CTRL-N and you will be prompted at the top of the modem display to enter a filename.  Give it any standard 8.3 format filename that is useful to you.  (8.3 is 8 characters followed by a period and 3 more characters as an extension, like “Test1234.txt”.) Don’t forget to use CTRL-Z key to end this entry.)

The other USB-related feature is that you may Insert your own text into the data stream being recorded to your USB flash device.  For example, after getting into REC mode (CTRL-U) but before starting up a QSO, you might wish to enter the current date, time or operator name in order to have a better record of the QSO downstream.  To do this, type CTRL-I and you will prompted at the top of the screen to enter this “offline” text.  Don’t forget to end your entry with a CTRL-Z in order to return back to Tx or Rx mode.  Remember, what you enter in this Insert mode is not transmitted, but it is only text that is inserted into the stream of data going to your USB flash memory device.
 

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FLASH BOOTLOAD -- Loads new modem software from a flash device

This feature allows you to upgrade your modem software from a file placed onto the thumb drive.  All you need to do is place a file containing the latest version of the modem software onto your thumb drive, as downloaded from the NUE-PSK website.  This hex file may then be easily programmed into the processor of your modem.  Thus, you no longer need to use a serial adapter to upgrade your modem software!

If you wish to try out the feature, you could follow these steps ...

1) Download the modem software mem1_33c_img.zip to your computer and unzip it to form the file called mem.dat, and then copy the mem.dat file to your thumb drive. 

2) Insert the thumb drive into the modem and select the Flash Bootload function in the modem menu underneath the Select pushbutton. (Hold the Select pushbutton down for more than 1/2 second and turn the dial counterclockwise until Flash Bootload is displayed.) 

3) Press the Select pushbutton and see "Abort" displayed beneath Flash Bootload.  Turn the dial one notch to see "Start Bootload" displayed. 

4) Ensuring that your thumb drive is inserted, TAP the Select pushbutton and in about 15 seconds your modem will reboot and start up the software version you just loaded.
 

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PC BOOTLOAD -- Loads new modem software from a flash device

This feature allows you to load a new version of a software hex file onto your modem from your PC, much in the same way as you did previously when using a serial adapter.

To use this feature, you follow these steps ...

1) Download the latest software to your computer, and then connect your modem to the USB port on your PC.  You will use a suitable cable that plugs into the square USB jack on the modem and into the rectangular USB jack on the PC. When you plug in both ends of the cable, the computer will recognize the USB port

2) Ready your PC (in the same fashion as done previously when using the separate serial adapter) by bringing up a Command Prompt window on the PC, navigating to the location where the PROG program and your modem software hex file reside (the root of the C: drive is convenient), and type:
                    prog  -i  com5  modem1_xx.hex
where the COM port number is that used by your PC for the USB ports, and modem1_xx.hex is the specific filename you are going to load per the latest release.  Do not hit <Enter> yet until you have readied the modem side of the connection.

3) Select the PC Bootload function in the modem menu underneath the Select pushbutton.  (Hold the Select pushbutton down for more than 1/2 second to bring up the menu and turn the dial counterclockwise until PC Bootload is displayed.) 

4) Press the Select pushbutton and see "Abort" displayed beneath PC Bootload.  Turn the dial one notch to see "Start Bootload" displayed. 

5) Press the Select pushbutton then hit the <Enter> key on the PC keyboard to run the PROG program.  You will see the standard series of about 100 dots appear on the PC screen to signify the program download process.  When the dots stop appearing, the modem will reset and the new software will be running.

NOTE:  You will need to have the FTDI USB driver installed before attempting to use this PC Bootload feature.  To install the driver,  download the driver installation zip file,  expand it onto a temporary file on your PC, and then plug in the cable from your modem.  With the modem power turned on, the PC will recognize that a new USB device is plugged in and Device Found Wizard will pop to lead you through the process of installing the new driver.  At the appropriate point indicate that you wish to specify that that PC searches for the driver at the location you have the temporary folder.  When the PC indicates that the device is successfully installed, you can use the PC Bootload feature.  NOTE:  If you need help with this process, you can download and study the FDTI application note called "AN232R-03 Driver Pre-Installation Document."

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REAL TIME CLOCK CALENDAR -- Maintains accurate date and time on the modem display, and timestamps added to QSO recordings to flash drive.

Once the RTCC components are added to the USB card, the modem's dsPIC controller is able to read the date and time and display this information on the main LCD. The USB+RTCC card has an onboard battery to enable the RTCC chip to "keep working" even when the modem is turned off.  Then when the modem is turned on again, the current date is once again displayed.  The v3.0 software also allows partial RTCC function even when the USB card or RTCC components are not present.  In this case, an elapsed time counter is presented on the display and again saved to the QSO file on the USB thumb drive in REC mode.

Date and time displayed on modem LCD
(Click on photo for larger view)

In receive and transmit modes, the date and time are displayed on the top line of the 128 x 64 graphical display. In other modes, the entire screen is used so the date and time are not displayed; however, the date and time are maintained so they will be current when next displayed. When first powered up, the time is initialized as “00:00:00” and the date is not displayed until the date is input to the modem either by the operator (see Configuration Menu) or by the optional USB option card (automatic, if installed). If the time is not updated, it can serve as a running time meter showing how long the modem has been turned on. The operator may also choose to turn the date and time displays off.

The date display is located in the upper left corner as an eight-character string formatted as:  “MM/DD/YYYY. The time display is located in the upper right corner as an eight-character string formatted as:  “hh:mm:ss” in a 24-hour format. To conserve display space, both are displayed using a special 3 x 5 font with no space between characters instead of the standard screen font which is a 5 x 7 font with one column of pixels between characters (6 x 7 pixels used per character).

The time is updated every second either by the Real Time Clock Calendar (RTCC) circuits on the USB option card or, when the USB option card is not installed, by a one-second timer in the modem. The main differences between these two approaches are accuracy and persistence. The RTCC on the USB option card uses the same type of crystal used in quartz watches to generate a very accurate time base.  The modem time base is derived from the main system clock and is less accurate. The RTCC is powered by its own separate battery so it will maintain accurate time even when the modem power is turned off. Each time the modem is turned on, it verifies that the RTCC is present and automatically sets its copy of the date and time from the current RTCC settings. When the RTCC is not detected, the user must manually enter the date and time each time the modem is powered up.

When the USB option card is first installed, the date and time settings will not be accurate. The operator must enter them once. From then on, the RTCC will maintain them whether or not the modem is powered on.  The RTCC knows nothing about time zones and daylight savings time. The operator can choose to use either local time or Universal Time and must change the time ahead or back one hour to account for daylight savings time, if desired. The RTCC programming is aware of leap years so it is not necessary for the operator to make leap year adjustments in the date. Of course, the operator will have to reenter the date and time after replacing the RTCC battery. (Note:  Whenever a battery is installed onto the USB card, pin 4 of PIC controller U3 should be grounded quickly once with a touch of a clip lead in order to properly reset the PIC and start the clock programming.)

Timestamping REC files

The QSO recording format for flash drives is enhanced with additional information including date and time.  At the start of each recording session (initiated by a CTRL-U) the following text block is written to the file:

*****************************************

* START RECORDING  <MM/DD/YY hh:mm:ss>  *

*****************************************

This text block is always followed by a blank line.  At the end of the recording session (terminated by another CTRL-U), the following text block is written to the file:

****************************************

* STOP RECORDING  <MM/DD/YY hh:mm:ss>  *

****************************************

This text block is always preceded by a blank line.

The start of each recorded receive session contains the following preamble text:

* * * RECEIVING:     <hh:mm:ss>

This text is followed by a single space character and then the received text as received, no formatting.

The start of each recorded transmit session contains the following preamble text:

* * * TRANSMITTING:  <hh:mm:ss>

This text is followed by a single space character and then the transmitted text as transmitted, no additional formatting.

When the operator inserts text in the recording (CTRL-I), the following text is inserted in the file:

* * * INSERTING:     <hh:mm:ss>

This text is followed by a single space character and then the operator-keyed text, no additional formatting.  When the operator ends the insert operation with CTRL-Z, the modem resumes recording the interrupted mode with the appropriate RECEIVING or TRANSMITTING preamble.