Interfacing

1. General

The program can interface with your radio using several ports from the computer. These ports are:

• Serial port - With a serial port it is possible to send CW, key PTT or communicate with your radio. Most computers nowadays have one Serial communication port with 9. Laptops mostly have one serial port but sometimes no serial port at all. When there is no serial port (available) a USB to serial converter can be used.
• Parallel port - With the parallel port it is possible to send CW and key PTT at the same time. There is additional info available on the parallel port. With this additional info you can switch antennas with the right interface connected. Also there is a pin that indicates which radio is currently active.
• USB port - The USB port can be used with a USB-to-serial converter. Not every USB-to-serial converter can send CW. Also devices like the microHAM - microKEYER can be used but have far more capabilities than just being a serial port converter. See the chapter Supported Hardware for more information.
• Sound card - The sound card is used to send sound (Wav) files to your radio for instance for giving CQ and for sending and receiving when using RTTY with MMTTY. The sound card can also be used to record all the QSOs you are making.

For CW the parallel and serial ports are assumed to have the default addresses shown in the list below. These addresses can be changed in the configurer to match your Windows setup.

These addresses used in Windows can be checked in 'Control Panel > System > Device Manager > Ports (COM & LPT) > (Choose a port) > Resources > Input Output Range'.

Nonstandard port addresses will not work for CW.

Tip

If you have one standard and one non-standard COM port, assign the non-standard to the radio, and the standard port to CW.

2. Radio interfacing

3. Interfacing for CW Keying and PTT

3.1. Parallel (LPT) Port

This is a typical simple interface

Parallel (LPT) port pinouts

• Pin 1 - Strobe
• Pin 16 - PTT output
• Pin 17 - CW output
• Pin 18 - Ground

3.2. Serial (COM) Port

Note

The CW and PTT lines for a radio must be on the same serial/parallel port. Example: When COM4 is the CW Port and Radio 1 or Both is selected, PTT control for Radio 1 must also be on COM4. USB-to-serial converters are supported, but USB-to-LPT (parallel) converters are not.

3.3. Using a transistor

• Equivalents for the 2N2222 are 2N3904, BC547 or BC548.
• NB. It isn't a bad idea to add a 1 kOhm resistor from base to ground, also adding a shunt capacitor of 10 nF is highly recommended at the collector output to ground in order to prevent RF feedback to base and subsequent blocking.

3.4. Using an opto-Isolator (opto-coupler)

Some users prefer to use an opto-isolator rather than a transistor, in order to provide more protection for the serial port in the event of something going wrong downstream. In that case, however, two special considerations may apply:

• You may need to place a diode in series with the input of the opto-isolator, to protect it from negative voltage swings on a standard serial port. Check the specifications of the opto-isolator you use to determine whether this is necessary.

• Some opto-isolators may not pull their output "low" enough (close enough to zero volts) to switch PTT or CW on a given transceiver. In that case, appropriate "pull-down" measures must be applied.

4. Via USB port

Not all computers have serial ports anymore or not enough to control transceivers, packet, serial CW keying etc. In this case consider a USB to serial port adapter. Most of them do nicely control the radio. The problem with these interfaces is doing CW and/or PTT (and 5 bit codes). Test before or ask around if they work for radio control, CW or PTT control with your computer and radio! Also look first if drivers for your operating system are available.

With N1MM CW will work with native serial ports and with USB-to-serial adapters. For perfect CW not dependent on Windows processes the answer is Winkey by K1EL. CW transmitted as normal ASCII characters via the serial port. A USB/serial adapter will work fine with K1EL, because it is standard serial communications. Check the Winkey manual for more information.

In some cases PTT and CW keying may unexpectedly stop working when using a USB-to-serial converter. Check this Windows setting:

• Control Panel; System Icon,
• Hardware Device Manager Tab or button.
• Expand USB Serial Bus Controllers
• Highlight each USB Root Hub
• Double click for Properties settings, Power Management tab,
• Remove the check mark from 'Allow the computer to turn off this device to save power'.
  • The box is checked by default in most cases.
• Reboot the computer

A table giving evaluations by N1MM users of various USB-to-serial converters is in the References Section. Another overview of serial- to-USB converters can be found at the RTTY contesting page by AA5AU at: http://www.rttycontesting.com

5. Additional Parallel Port Interfacing

If the type of CW port chosen is LPT1, LPT2 or LPT3, and a hardware LPT port is used, additional information will be present on the chosen parallel port. In configurer select for which Radio the output has to be given on the selected port (Radio 1 or Radio 2). The BCD data on the LPT is that of the current active radio/VFO. The band data is available on multiple LPT ports — Radio 1 on LPT1, Radio 2 on LPT2 and so on. USB-to-LPT converters are not supported.

When DVK is selected, the Antenna selection via the LPT port is disabled. The DVK pins and the antenna pins on the LPT port overlap. Parallel port pin layout

6. Band decoder output

Pins 9, 8, 7 and 2 can be set using the Antenna tab in Configurer. The output on the pins will follow the selected code which is being set up by the selected antenna.

6.1. Sample configs

To replicate the default Top-Ten Devices behavior, you would need to set up the Antenna tab in Configurer as shown above to the left| It is possible to use more than one antenna per band with N1MM logger. With Alt+F9 it is possible to toggle between these antennas. NB. Don't forget to add a space after the comma when more than one band is specified (e.g., 7, 3.8, not 7,3.8)

6.2. Sample Config > Antenna for two stacked antennas

You will need to make appropriate provision with a diode matrix on the output of your band decoder to select the appropriate antenna or antennas when a given code is sent from the program to the decoder. For example, if your band decoder outputs positive voltage

7. Bearing data

Bearing data for rotator control is currently not available on the LPT port.

8. Sound card interfacing

8.1. Preferred method

It is better to run the mic through the sound card all the time. That way your audio sounds the same either recorded or live. It also lets you re-record cq's on the fly, something that is really needed for 40m and 80m split cqing. Check out "#1 - Zero or Single Card, One radio, No Sound Card SO2R " which can also be found with more examples in the SO2R section.

Select '1 - Single Card - One radio, No Sound Card SO2R' on the 'Audio' tab in the Configurer and setup the top part of this dialog. The sound is centered rather than set to a radio channel.

8.2. Another possible soundcard interface.

This is NOT the preferred method any more!

• A 8:1000 ohms transformer should be used when the sound card speaker output is used to the radio microphone input.
• A 600:600 ohms (1:1) transformer should be used when the line output from the sound card is used to the radio microphone input.

9. Serial and Parallel port interfacing under Windows NT/2000/XP

Windows NT, Windows 2000, XP and their descendants require a special dll, DLPORTIO, which will be installed by running: PORT95NT.EXE to use the parallel, serial and USB ports. Windows 95, 98 (SE), ME don't need this special dll. In these operating systems N1MM logger can access the parallel port direct without the need for an extra driver.

To install the NT/2000/XP capable dll, do the following:

• Download PORT95NT.EXE. A link to this file can be found in the installation section.
• The size is about 1,6 Mb.
• To install, just run port95nt.exe
  • Select Next, Yes and typical where appropriate.
  • Yes to boot your PC
  • You are done.
• You have to be the administrator of your machine when running port95nt.exe

9.1. Everything on one COM port

By Uffe PA5DD.

Shared ports allow for example Radio control/PTT/PTT-interrupt/CW on just one COM port, which might be all you have on your laptop. It requires that you make a serial splitter or a common interface. There are some pitfalls though:

• Radio control communication is without hardware handshake (as you are using the hardware control pins for other purposes). This is not a problem as such, since hardware handshake is not used by your radio. True at least for ICOM & YAESU.
• Some interfaces wire RTS/CTS together to allow a PC set for hardware handshake to work properly. This link must be removed for port sharing, as it will generate a permanent PTT interrupt on the CTS pin. This will abort your messages as soon as you start them. Also DSR should not be connected to anything.
• In some radio control serial level converters the handshake signals are used as power supply. This is not possible if both RTS & DTR are used for CW/Other. You will have to provide power supply from somewhere else (I use the PS/2 mouse port). Note that in this case you only have to split out GND TXD RXD for the radio control.

9.2. I need more serial ports

By Didier KO4BB

Interrupts are the limiting factor to more than a handful of serial (com) ports. There are 2 ways to address that:

1) You want to use "standard" hardware using Windows "standard" com port model, and as long as the software will let you select IO port and IRQ, and as long as you don't need parallel printer or floppy (and as long as your video card does not use IRQs also), and if the program lets you share IRQs (for instance, you don't need an IRQ for a serial port used to drive the PTT line), (that's a lot of if's!!!) you can probably cram 4 to 6 com ports into a single PC. Note that you may still have problems if you try to run high bit rate on all the ports at once (that should not be a problem with radio control though). Please note that the "standard" PC setup (and Windows) supports 4 com ports with only 2 IRQs. Those who have tried know that you don't want to run high bit rate on COM 1 and COM 3 at the same time because they share the same IRQ.

2a) You do away with standard hardware, and then you can use specialty boards that have 4, 8 or even 16 ports. However, these boards use communication processors so they only need one IRQ from the PC but your software needs to be aware of and be able to communicate with that processor, either through custom software, or through a driver for your OS (Operating System i.e. Windows), or both. That's what ISPs use to gang a bunch of modems to support more than a couple phone lines/modems with each PC. While these may have high communication rate capabilities (because the communications processor uses FIFOs, small memory buffers that store incoming data until the PC is ready to take it), they also offer higher latency (response time) than a native port, not ideal for CW, although with a fast PC, most users have been satisfied with this setup.

2b) USB adapters fall in the category of non-standard hardware, but because USB is now built into the motherboard, the communication processor hardware is directly supported by the BIOS, and the OS has the proper drivers, so that has quickly become a standard. However, the USB standard was not designed to minimize latency, so a USB-serial adapter, while OK to talk to a radio via it's serial port, is not ideal to do things such as CW using bit twiddling. That should be reserved to native serial or parallel ports (motherboard or add-on card). USB adapters are probably a little worse (with regard to latency and CW capability) than custom communication processors described at 2a) because the USB adapters communicate with the PC through a serial link instead of being directly connected to the processor bus, so the bit twiddling has to be done though a serial link, which adds latency. In addition, since the USB port may be shared with other devices, accessing these other devices while sending CW would be a bad thing.

Bottom Line: There are excellent USB combination interfaces now available that can control one or more radios, key them with Winkey, and even provide soundcard facilities.

9.3. Renumber your serial ports

As you install new serial ports (serial or USB devices) Windows may arbitrarily assign COM port numbers to them that are outside the COM 1-8 range of the N1MM Logger configuration menu. Reassign the serial/USB port to a different number. Here's how:

1) Right click "My Computer"
2) Left click on "Manage"
3) Left click on "Device Manager"
4) Look in the right window and find + Ports (COM & LPT)
5) Left click on the Plus sign
6) Right click on the COM17 line
7) Left click on the "Properties" selection
8) Left click on the "Port Settings" tab
9) Left click on the "Advanced" button
10) Select the COM Port Number you want in the drop down menu
11) Click on "OK" a bunch of times to back all the way out
12) Your serial/USB port number will now appear as the number you chose

If you have more than one COM port, you can change them all by selecting each one in turn and going through this process.

73 de Bob - KØRC in MN

10. Hooking up a Footswitch

A footswitch can be hooked up to a serial and a parallel port. The footswitch program action is for both LPT and COM ports on switch closure.

10.1. Parallel port

Hooking up a footswitch to LPT1 can be done by connecting a 10k resistor from pin 14 to pin 15 of LPT1. Pin 14 is +5V (see note below). Then connect a normally open footswitch between pin 15 and pin 18 of LPT1. Closing the footswitch pulls pin 15 low and performs the function selected in the configurer. Note: pin 14 also used for Radio A/Radio B control of external boxes, so that it won't always be +5 volts . If this is the case an external +5 V power supply can be used.

10.2. Serial port footswitch information (using the 9 pin connector numbers)

Connect a 10k resistor between pin 6 and pin 7. Set DTR, pin 4 to "Always On" and RTS, pin 7 to "Always Off". Connect the footswitch between pins 4 and pin 6. The program action will be on footswitch closure. The footswitch wires can not be referenced or connected to ground.