Vintage displays (Part 2)

  Some  earliest LED displays for military ground equipment and industrial applications:
HDSP-2490, ceramic DIP, year 1989, red LED color:

 20x optical zoom

200x

500x

500x, same picture but with different light position, light shines from above through the lens, silicon die part number 1BU9B with HP logo and photo-lithography alignment squares 

500x

500x LED crystal itself, all crystals connected into 5x7 LED matrix, similar to HDSP-2000

with 2000x we can see purple ceramic crystals and gold coating structure

300x

 HDSP-2451, year 1985, yellow LED color:

200x

500x, silicon die part number 1BU8B, ancestor of HDSP-2450 from 1989

500x, tiny wires connected with dot welding

500x

200x and LED crystal

Vintage nixie tubes clock with SN74 logic

Here is my 24H  Nixie clock project, the original goal was to construct a six digit nixie clock using only SN74 hard logic, also in my checklist for this project:

• Internal (DS32KHZ) / external (1PPS from GPS) time synchronization
• On board 3.3V power supply for external GPS receiver (Fastrax UP501 or similar)
• 5V single supply operation with regular Arduino power jack
• LED backlight for nixie tubes
• Switchable control of  blinking dots 
• Push button control for time setup
• Seconds reset  for accurate time setup

Schematic is pretty simple, it consist of four Divide-by-eight counters (SN7493) to get a 1PPS signal from 32768Hz (DS32KHZ oscillator), decade counters (or divide-by-five SN7490) and Divide-by-six (SN7492) counters, BCD-to-Decimal decoders (SN74141) for nixie tubes operation. Time setup is controlled by SN74153 multiplexer, it switches 1PPS signal between minute and hour counters to adjust time. For GPS synchronization Divide-by-eight counters (4x SN7493) are optional as well as DS32KHZ Temperature-Compensated Crystal Oscillator, 1PPS can be applied directly to seconds counter input. Any digital TTL compatible logic from SN54 or SN74 series can be used for this project, including original SN74 and F, LS families, also there are lot of military grade SNJ54 integrated circuits in ceramic DIP available from eBay.  In this project I also used Russian cross-references for SN74141 (155ID1) and SN7493(155IE5). Nixie tubes power supply (5V-170V) was purchased off eBay.
Time setup sequence:

1. Press and keep seconds reset button to prevent seconds count
2. Press minutes setup button and adjust minutes
3. Press hours setup button and adjust hours
4. Release seconds button or press it again for precision time setup

And that's it. Lots of vintage electronics and very old nixie tubes from 70’s and I have my finished  Nixie clock.
  
Schematic

 

 

490IP1 - Russian LED display for avionics and military applications

Some time ago, I purchased interesting russian LED digital display 490IP1 (К490ИП1) from Ebay. According to information from seller, it was used mostly in avionics and military applications because of the small size. This display measures only 12mm x 5mm!

Now, how to hook it up to a microcontroller? 490IP1 has only few pins for control, so after some experiments I found that:

pin#9 -DOT control

pin#2 -Display Blank

pin#6 -Reset

pin#7 -Count

pin#1 -Display power 5V

pin#5 -Logic power 5V

pin#8 -GND

You may think that this is something like HDSP1414 or NSM1416 because it has some control logic inside but it appears that 490IP1 is a simple decade counter with separate power for display itself and control logic! Just apply reset to start then toggle count pin until desired digit is reached, you can also turn off the display during the count with pin#2. I believe these displays are stackable and you can use pin#4 for this purpose. Basically control looks similar to TIL307 but display features are significantly reduced comparing to Texas Instruments TIL307 version.

CY8CKIT-042 kit from Cypress was selected for this experiment as it has 5V tolerant MCU. Simple test code.

Picture from datasheet:

Video

IGT1-203 Self Scan bar graph display

Another bunch arrived on my workbench, my recent eBay purchase, IGT1-203 plasma bar graph display. This is single channel self scan plasma display with a working principle similar to  PBG12201  panel indicator (Love that glow in the dark!). IGT1-203  has   5 scan  cathodes, one reset  segment/cathode, one anode for linear control, and two keep-alive pins. 

Simple STM8 library was written to drive this IGT1-203 display panel.  It  uses  one  ADC channel, TIM4 scan  timer and embedded IDWG  watchdog for better stability.

 Schematic is pretty simple:

Video

S35190 3-wire RTC clock library for STM8003F3U6

S35190  is  a   3-wire  real-time  clock  IC with automatic time correction feature (hardware compensation). This is very useful option because  most  of  RTC crystals are not precise and require calibration or external  trimmer capacitor.

 

This simple  library  was  developed  on  STVD  4.3.6, built with Cosmic compiler. Reads/writes year, date & time, UART is pushing out the data.

PCB with 2x2 mm RTC S35190 timer and 3x3mm STM8003F3U6 micro-controller.
Library.

Thingspeak with ESP8266 board

Thingspeak  allows  you store your data in the cloud  and do calculations. This is very useful  because  large  data from sensors always available online without microcontroller memory waste.

Looking  at  some  of the examples for ESP8266 processor I was able to get  this board stream data directly to Thingspeak.

Here is my feed with the temperature,   pressure   (BMP280),   magnetometer  (MAG3110), humidity   (CC2D33)   and   light   sensor  (BH1750)  data.

Texas Instruments Analog Engineer's Pocket Reference

This is another handy little book from TI, really good book that has almost everything you may need for everyday engineering. All the pages are in color, lot of useful formulas and tables relating to analog and digital electronics. Nice deal for only 5$! A must have for engineers! 

PS Book also available for download in PDF 8.8MB