N3ZI Kits - NEW Digital Dial / Frequency Counter
With Universal LCD Capability.
Connectors for 14, 16 pin in-line, 14/16 pin 2 row, and 10 pin serial.

Improved version for 2012.
Close up
(Above photo shows Kit with Serial LCD and cable/connector kit)
(This version $29.95)
2012 Version NOW SHIPPING
NO SMT Components, all parts are conventionial through hole

Which Kit

The kits with LCDs only include the necessary components to drive the supplied LCD.
The experimenters version (which includes no LCD) includes components that will allow the drive of many different LCD types.
Including a higher power regulator for LCDs with larger backlight current draw, and negative LCD bias option.
Photos below show the version with the backlit LCD
 PCB Close up Blue Backit LCD
Stack Stack Side
(This version $35.00 incl LCD shown)
Mounting hardware Sold Separately, available here

EXp Ver

Experimenters version: This version is offered to those who wish to experiment with different LCD types. This new design supports LCD's that require a negative LCD contrast voltage.  This is done, NOT using a switching supply, but a simple ground offset mechanism.  Simply, from a 12V power source we generate +1.4v and +6.4 volts using a linear regulator.  (see schematic below) The LCD and logic have thier ground tied to the +1.4v, and power tied to +6.4v thus they see +5v.  A connection to the real ground appers to be -1.4 volts to them.  When people are selling LCDs they rarely mention the fact that they require a negative voltage, but you run into them from time to time.  Also many LCD's contrast is temperature sensitive, and LCD that looks fine at room temperatire, will need a negative contrast voltage at low temperature. The experimenters version also includes a higher power voltage regulator for LCDs that require up to 100mA of backlight current. The experminers version is sold without an LCD.

This version $25.00 (No LCD)


Features and specifications
  • Programmable IF frequency, and VFO mode (VFO+IF, VFO-IF, IF-VFO)
  • Supports up to 9 different IF offsets
  • S/W Programmable to accommodate /n prescaler (n can be 2,4,8,16)
  • On board voltage regulator allows normal operation from 11 to 15VDC power source.
    • Battery operation possible by bypassing on board regulator, ~3mA at 3-5 VDC
  • 2 pushbuttons required only for programming IF and Formula.
  • All programmable options stored in non volatile EEPROM, so they only have to be set once.
  • Input Sensitivity: 150mV RMS see chart.
  • uCode, includes anti jitter s/w which prevents LSD from jittering between two values.
  • Measures VFO frequency up to 80 Mhz with Div/16 prescaler
  • 32 bit internal math
  • 100 Hz or 10 Hz display resolution.
  • No XTAL trim cap required, correction applied in S/W.
  • Update rate approx. 20 ms w/o prescaler. 80 ms with /4 prescaler.
  • NO soldering of Surface mount components required.
  • Standard LCD has Large 0.375 inch digits, dimensions 4.88 x 1.25 inch
  • Supports many different 3rd party LCDs
    • Supports 14-16 pin 44780 LCD Modules w/ either 2 row or single row connector
    • On board driver for LED backlight
      • Up to 20mA when using the 78L05 regulator in a TO92 package
      • Up to 100mA when using the 7805 in a TO220 package, no heatsink
      • Up to 250mA when using the 7805 in a TO220 package, with heatsink
  • Read reviews on EHAM

Manuals, Schematics, and technical notes

LCDs: I will likley not be stocking any other LCDs. There are many different colors and sizes available on ebay for very low prices.  Just about any of the character LCDs will work. The firmware supports 8x2, 16x1, and 16x2 displays, anything larger will work, but the extra lines/digits will be blank. (It will not work with graphics LCDs, or glass only)

PCB Dimension are approx 3.1 in x 1.4 inches, which is about the same as most 16x1 and 16x2 displays.
The small 8x2 Display shown in the picture below is about 1.5in x 1.3in
The displays with a 2 row connecter are easiest to remote with standard flat flex cable and IDC connectors.

Small LCD
Shown above is the Kit configured for a LCD with a 2 row connector. Note extra jumper, white wire for backlight.
I do not stock these smaller LCDs but they are readily available on ebay.
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