Difference between revisions of "VFO-001"

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(Created page with "'''This is a work in process - Gathering pieces.''' File:HW-9.PNG == Features == Replace HW-9 internal VFO with a digital VFO * HW-9 VFO has legendary issues ** Mechan...")
 
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== Features ==
 
== Features ==
  
−
Replace HW-9 internal VFO with a digital VFO
 
−
 
−
* HW-9 VFO has legendary issues
 
−
** Mechanical issues with vernier
 
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** Drift due to thermal
 
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** Lack of resolution
 
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** Backwards dial
 
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* Fits within HW-9 VFO Box
 
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* Controls Tx/Rx/BFO frequencies with rotary encoder
 
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** 10 Hz steps
 
 
* DD1306 OLED Display
 
* DD1306 OLED Display
 
** I2C Interface
 
** I2C Interface
−
** "Curved" display
 
−
* Uses RIT control on HW-9
 
−
** +/- 1 KHz RIT
 
 
* Blue Pill Microprocessor
 
* Blue Pill Microprocessor
 
** Arduino compatible
 
** Arduino compatible
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* Understands band switch for MHz displayed
 
* Understands band switch for MHz displayed
 
* Si5351 Oscillator
 
* Si5351 Oscillator
 +
** 10 Hz steps
 
** I2C Interface
 
** I2C Interface
 
** 3 Outputs
 
** 3 Outputs
−
*** Transmit frequency
 
−
*** Receiver frequency include offset plus RIT
 
−
*** BFO frequency
 
−
** Low pass filters to turn square waves to sine waves
 
 
** 27 MHz crystal
 
** 27 MHz crystal
  
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[[File:VFO-001-SCHEMATIC.PNG]]
 
[[File:VFO-001-SCHEMATIC.PNG]]
−
 
−
== Connections to Radio ==
 
−
 
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* RIT pot
 
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** Connects to Analog input
 
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*** Polled occasionally while in receive
 
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* Band switch
 
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** SW1 9V
 
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* T/R - transmit/receive
 
  
 
== Parts ==
 
== Parts ==
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==== Measurements ====
 
==== Measurements ====
  
−
==== VFO TX ====
+
== Libraries/Example Code ==
−
 
 
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* 250 KHz range
 
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** From 5.9993-5.7493 MHz
 
−
 
 
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==== VFO RX ====
 
−
 
 
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* RIT knob is taken in through an A/D and adjusts the receive frequency plus/minus 1 KHz
 
−
 
 
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==== BFO ====
 
−
 
 
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* 8.8314 MHz in receive
 
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* 8.8307 MHz in transmit
 
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* 700 Hz difference but could be adjusted
 
−
 
 
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=== Low Pass Filters ===
 
−
 
 
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* Si5351 has square wave outputs
 
−
* LP filter can be used to change squarewave into sinewave
 
−
* [https://rf-tools.com/lc-filter/ LC Filters Design Tool] - calculator
 
−
* [https://kitsandparts.com Kits and Parts dot Com]
 
−
** [https://kitsandparts.com/lpf.1.5.php Build a 7-pole Universal Low Pass Filter for HF]
 
−
** Butterworth
 
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** Replace with SMT card?
 
−
 
 
−
[[File:LPF.1.5.sch.png]]
 
−
 
 
−
[[File:LPF.1.5.pcb.png]]
 
−
 
 
−
* [http://toroids.info/FT37-43.php Toroid Calculator]
 
−
* [https://kitsandparts.com/PCBs/LPF/filter2.pdf A short guide to harmonic filter for QRP transmitter output]
 
−
** [https://www.mouser.com/ProductDetail/Pulse-Electronics/PE-0805CLH1R5STS?qs=82jvyl5dHWdaYiLrQ038Kg%3D%3D PE-0805CLH1R5STS Example 1 uH inductor]
 
−
** [https://www.mouser.com/Search/Refine?Keyword=PE-0805CLH Search PE inductors]
 
−
** [https://www.mouser.com/Passive-Components/Inductors-Chokes-Coils/Fixed-Inductors/_/N-wpczZ1yzvvqx?P=1yzvlksZ1z0wqjdZ1z0woesZ1z0wrifZ1z0wri6Z1z0wrhxZ1z0wrhoZ1z0wrhfZ1z0wpbo&Ns=Pricing|0 Broader search]
 
−
** [https://www.mouser.com/Passive-Components/Capacitors/Ceramic-Capacitors/_/N-5g8mZ1yzvvqx?P=1z0z7ymZ1yxboka&Rl=5g8mZer3vZ1z0x74kZ1z0x7xwSGT&Keyword=0805&Ns=Pricing|0 0805 caps C0G]
 
−
 
 
−
 
 
−
[[File:LCFilterValues.PNG]]
 
−
 
 
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* VFO and BFO frequencies are outside the bands (deliberately to void collisions)
 
−
 
 
−
==== BFO Filter ====
 
−
 
 
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* 8.8314 MHz in receive
 
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* 8.8307 MHz in transmit
 
−
 
 
−
[[File:BFO_Filter.PNG]]
 
  
−
[[File:BFO_Filter_IL.PNG]]
 
−
 
−
== Libraries/Example Code ==
 
 
* [https://github.com/land-boards/lb-Arduino-Code/tree/master/STM32/VFO_Si5351 Land Boards Application]
 
* [https://github.com/land-boards/lb-Arduino-Code/tree/master/STM32/VFO_Si5351 Land Boards Application]
 
* [https://github.com/pu2clr/VFO_BFO_OLED_ARDUINO VFO and BFO with Si5351A, OLED and Arduino]
 
* [https://github.com/pu2clr/VFO_BFO_OLED_ARDUINO VFO and BFO with Si5351A, OLED and Arduino]

Revision as of 13:48, 24 October 2020

This is a work in process - Gathering pieces.

HW-9.PNG

Features

  • DD1306 OLED Display
    • I2C Interface
  • Blue Pill Microprocessor
    • Arduino compatible
    • 3.3V
  • Understands band switch for MHz displayed
  • Si5351 Oscillator
    • 10 Hz steps
    • I2C Interface
    • 3 Outputs
    • 27 MHz crystal

Schematic

VFO-001-SCHEMATIC.PNG

Parts

Blue Pill Card

STM32F103C8T6-Blue-Pill-Pin-Layout.gif

  • 3.3V operation work without level shifters for I2C
    • OLED can run from 3.3V
    • Si5351 can only run from 3.3V
  • Used right angle headers and Dupont cables
  • Replaced BOOT 0,1 jumpers
    • Jumper on BOOT1
    • Switch on BOOT0 - easier to download code
  • Download via serial
  • Arduino IDE

128x32 OLED

Si5351 003 720px.jpg

OLED128x32.PNG

Arduino Library for OLED

U8G2_SSD1306_128X32_UNIVISION_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE);   // STM32, Ebay OLED

  u8g2.setFont(u8g2_font_ncenB14_tr);
Hello World Code
U8G2_SSD1306_128X32_UNIVISION_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE);   // STM32, Ebay OLED

void setup(void) {
  u8g2.begin();
}

void loop(void) {
  u8g2.clearBuffer();			// clear the internal memory
  u8g2.setFont(u8g2_font_ncenB08_tr);	// choose a suitable font
  u8g2.drawStr(0,10,"Hello World!");	// write something to the internal memory
  u8g2.sendBuffer();			// transfer internal memory to the display
  delay(1000);  
}

Rotary Encoder/Breakout Board

RotaryEncoderCAD.PNG


Si5351 004 720px.jpg

Si5351 Frequency Generator

Si5351 001 720px.jpg

VFO3.PNG

  • I2C Daisy-chain connector
  • 3 outputs
    • Tx
    • Rx (may not need to use separate output)
    • BFO - could be adjusted

Si5351 002 720px.jpg

Measurements

Libraries/Example Code

Videos

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