Saturday, 21 November 2020

New computer setup

 As I mentioned a couple of posts ago my old iMac failed. My son has given me his Mac mini - thank you.

I have purchased a superb 15.6" 16:9 screen and a new Apple keyboard. Both are amazing. Here's my setup now

Currently running Windows 10 under Paralles, and ELAD FDM-SW2 connected to my ELAD FDM-DUO transceiver.

Whopee, back in business.

Wednesday, 18 November 2020

More Mac Big Sur chaos

So WSJT-X does not work on OS 11, Big Sur. It returns the famous Memory Error. WSJT-X uses a shared section of memory to swap data between it's "two" apps, the waterfall and the control window. On previous versions of Mac OS (e.g. Catalina) the amount of shared memory was about 7MB, but WSJT-X needed 14MB.

The shared memory could be increased by changing the memory size in a file called /etc/sysctl.conf. But on Mac Big Sur this file is no longer present! And so far I have not discovered what replaces it.

I guess eventually the WSJT-X development group will solve the issue, but until then I will use my Mac Mini which still runs Mac OS Catalina and runs WSJT-X perfectly.

Tuesday, 10 November 2020

iMac HDD failure

 Whoops. All of a sudden Mac OS Catalina fails and crashes on my rather old (2012) iMac. Oh dear.

First I decide to try re-formatting ("Erasing") the HDD, this fails. I try again using an older file format, and it works. So I re-install the original OS Mountain Lion and this runs, but any attempt to upgrade to the latest Catalina fails (Catalina partitions the HDD into Programs & Data, I guess this doesn't work...))

Off to the Apple store and get a test. This reports that the HDD has indeed failed on one sector. They suggest I can recycle the iMac (offering a miserable £100) and they tell me the computer is too old to repair - they have no HDDs to put in it!

This is all very sad. Until my son offers to give me a 2015 Mac Mini he has but is not using - the kids were using it for school work - mostly in Microsoft Word etc. But he has no Key Board nor a screen display spare to offer with it. I shout whoopee for he has upgraded the RAM to 16GB and put in a 256Gb SSD which has speeded it up enormously.

So now I have to solve a couple of problems

1. Access the machine to sort it out, basically erase everything and install Catalina and set it up with my name and iCloud address. To do this I wire it up HDMI to my living room TV! And use the old iMac keyboard and mouse. It works a treat. I return the iMac for recycling.

2. Meanwhile I source a screen and use the £100 they will give me for my old iMac to buy a new keyboard (I have a spare Track Pad). I purchase a 15.6" screen on eBay, it arrives broken and I am struggling with the supplier to replace it or give me my money back... we will see.

But in the mean time I have configured the new Mac Mini to allow screen sharing and can access it very easily from my MacBook over wifi. So that is what I am  doing. And making lots of FT8 QSO with WSJT installed.


Days later I purchase a "very" expensive 15.6" screen, which is luxury and perfect with a 16:9 ratio & HDMI interface. I am very pleased with it.

Wish me luck.

Wednesday, 30 September 2020

My Small Shack

My shack is small and ALL indoors. The antenna is a small 60cm loop a-top an Auto ATU here:

You wouldn't think with my 5W you could get far with that, would you? But I enjoy my contacts using digital FT8 mode, especially on 20m. This is the rest of my shack, first the big picture:

Left to right, GPS clock, iMac, MacBook, FDM-DUO and 13.8V PSU

The GPS clock has been described in this blog below, it runs beautifully, but I have not yet boxed it up... The old iMac is a bit on the slow side, but runs WSJT, Grid Tracker and displays my log file. Underneath the iMac is a low cost Android tablet running ELAD Blueduo app. This gets spectrum and CAT data from the FDM-DUO transceiver via a small Bluetooth dongle and displays it. Next is the MacBook running Parallels and Windows 10, and then running the ELAD FDM-SW2 SDR suite. Lastly is the FDM-DUO transceiver itself with a home made 13.8V power supply, also described in this blog.

And here is the iMac running WSJT for FT8 mode:

iMac running WSJT

And the MacBook running Parallels, W10 & FDM-SW2, zoomed in on 14074kHz FT8 signals.

MacBook running Parallels, W10 & FDM-SW2

The FDM-DUO transceiver - an elegant, very small, very hi-tech SDR. With amazing performance, an almost entirely digital radio. But low powered at 5W output.

On the left a Bluetooth dongle to communicate with 
the Android tablet running Blueduo app.

The Android tablet running Blueduo app. Displays the spectrum and waterfall, and is able to control the FDM-DUO by CAT commands. 

Android tablet running Blueduo.

And that is it. Latest conquests, W. Sahara and Cyprus. That's DX for me!

Monday, 28 September 2020

Extensive Arduino course

For beginners or to catch up. Here is a full Arduino course, with course notes and all the sketches you need. I suggest you use this starter kit, it has all the pieces you need.

The kit is available from here. But add an LCD I2C interface here.

Please use it, copy it, distribute it. All free of charge!

Monday, 21 September 2020

E-paper weather monitor

Weather does not change very quickly, so it is one of the things that can be displayed on a e-paper display which cannot be updated on the fly, but only as the whole screen at a time.

There is a product called DHT11 on the market which measures temperature and humidity, from which you can calculate the dew point.

These are easily used in an Arduino sketch with a library called dht11.h (download here). This is the project

Sketch EPD_TEMP is here. You also need the updated epda.h header here, put it in your libraries folder. 

Good for SOTA activations and field days!

Thursday, 17 September 2020

Using E-Paper Display - Adafruit 200x200 BW

My son has a project that needs a display that must conserve power. E-Paper displays use NO power at all when not updating, and when the power is off they maintain their display! Incredible.

The problem with EPDs is that they need a buffer RAM on the microprocessor to store the entire display, in my case 200x200 pixels = 40,000 bit or ~8KB. The usual Arduino UNO or Nano only have 2KB. But the Adafruit display 1.54" 200x200 pixel Black and White display module has a additional 8KB SRAM built into the module to act as the buffer.

The graphic libraries (load using the Arduino IDE Library Manager):

Adafruit_GFX - graphic functions

Adafruit_EPD - display drivers

handle the use of the module 8KB SRAM automatically for you. Here's an example:

Connections are below

I have written a useful "header" file of functions for displaying text and numbers - it can and will be expanded I am sure to other function such as Date and Time. These are the current functions

Readme Epda.h

Adafruit 200x200 BW E-Paper Display. 

Include Adafruit_GFX and Adafruit_EPD libraries

Connections - uses SPI for display and 8kB SRAM.

SCK 13, MISO 12, MOSI 11

ECS 10, DC 9, SRCS 8



Adafruit_SSD1608 epd(200, 200, DC, RST, ECS, SRCS, BUSY);

Colours, use prefdefined colours



dispInit() // call in Setup() to initialise display

dispMsgS(uint8_t x, uint8_t y, uint16_t c, char *m) // text small

dispMsg(uint8_t x, uint8_t y, uint16_t c, char *m) // text normal

dispMsgL(uint8_t x, uint8_t y, uint16_t c, char *m) // text large

dispMsgUL(uint8_t x, uint8_t y, uint16_t c, char *m) / text Ultra large

dispNumS(uint8_t x, uint8_t y, uint16_t c, float n, uint16_t d) // number small

dispNum(uint8_t x, uint8_t y, uint16_t c, float n, uint16_t d) // number normal

dispNumL(uint8_t x, uint8_t y, uint16_t c, float n, uint16_t d) // number large

dispNumUL(uint8_t x, uint8_t y, uint16_t c, float n, uint16_t d) // number ultra large

dispDate(uint8_t x, uint8_t y, uint16_t c, uint8_t dw, uint8_t da, uint8_t mo, uint8_t yr) // date

dispTime(uint8_t x, uint8_t y, uint16_t c, uint8_t h, uint8_t m, uint8_t s) // time

dispTimeL(uint8_t x, uint8_t y, uint16_t c, uint8_t h, uint8_t m, uint8_t s) // time lsrge

dispClear() // clear display

dispDisplay() // display

x pixels across

y pixels down

c colour

m message

n number

d decimal places

As you can see this is the same approach I have used for small OLED (Oled.h) and colour TFT (Tft.h) displays. This readme and the header file "Epda.h" are  here.

There is a demo/test file EPD_TEST for the display here that shows how to use it.