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Tuesday, February 7, 2017

ZL1UEM'S Tiny OLED Si5351 Arduino VFO

Hugh ZL1UEM has come up with a very creative way to take maximum advantage of the small size of the Si5351 board, the Arduino, and the OLED display.  He even has the rotary encoder in there.  Look carefully -- he uses both sides of the board.  Very nice. Thanks Hugh!

Hi Bill,

First let me say that I have been an avid follower of the SS blog and podcasts since the days of your podcasts involving Mike KL7R.

Like many others I was tempted to purchase the $49 surface mount module from HF Signals.  As a keen home brewer I felt guilty about employing a prebuilt board but excused my decision on the grounds that I would build a DDS and other accessories myself.

In addition to follow the SS blog I also check Pete's blog regularly and was excited by his OLED VFO for the Bitx40.

I constructed it on a small double sided matrix board with plated through holes.  A bit of noodling led to the layout shown in the photos.  There is only one board with components mounted on both sides.  The board came to life on the first power up but the text spilled off the bottom of the display.

I assumed that the sketch that I had downloaded from Pete's blog was for a different OLED module.  I knew that he had also used a yellow/blue OLED, the same as mine, previously so emailed him requesting a sketch for this OLED.

I was taken aback when he informed me that the sketch I had was the same for both the dual colour OLED and the black and white one too.  Pete suggested that I swot up on the use of OLEDs generally and that perhaps I should first experiment with the text size to begin with.  He also offered some advice about the mapping of the screen.

I soon discovered that the text size was not the cause of my grief and that I needed to look elsewhere.

I first tried running the ssd1306_128x64_I2c sketch from the sample sketch folder and was rewarded with the message "Height incorrect, please fix Adafruit _SSD1306.h".  A search of the Internet revealed that I needed to edit the .h file and find "#define SSD1306_128_64" which was commented out and uncomment it and make sure that the other two options, _32 and _16, were commented out.

My next problem was how to edit the specified .h file.  I tried notepad but the text all ran together.  Another internet search revealed that Notepad++ was a suitable choice and it did indeed cut the mustard.

A reload of the sketch completely restored the display to full functionality.

All this may be obvious to many but it was all new to me and if I had not been prompted by Pete l would not have had learnt so much and would not have had the same sense of achievement when it all came together.

Many thanks to you and Pete for providing a focus for my hobby.



  1. Nice arrangement. I don't think you could make it any smaller. Good job OM!

    Dean AC9JQ

  2. A link to the code will be very usefull! 74 de YO3HJV

  3. https://produto.mercadolivre.com.br/MLB-1107591947-si-5351-kit-_JM


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