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

Interesting SHARP EL-8110 calculator with DSM LCD display

One pretty interesting item I picked up on Ebay recently. This is very unusual SHARP EL-8110 calculator with bizarre LCD display from the early 70’s. Actually I don't need a calculator, but this one I purchased just because of amazing display with white LCD segments! So after a bit of searching I found what before the appearance of traditional LCDs with black segments, COS or DSM displays with white segments were widely used, mostly in watches and calculators.

Contrast of the display is very low because of the white segments and reflective mirror coating. This display requires protective bezel or flap to increase the contrast. Also in this EL-8110 model protective flap directly connected with ON/OFF switch and it opens and closes each time you powering up the calculator.

SHARP EL-8110 calculator

Calculator is very simple inside, only one DIP-40 Toshiba T3289 processor with switched power supply, few transistors and capacitor.

Reflective metal coating

Calculator powered by two 357 batteries

Very unusual design of spring elements for rubber buttons.

Vintage LED displays (Part 1)

Here are some vintage LED displays that I have in my collection. All pictures was made with with Zeiss optical microscope. 

HPDL1414 / DL1414 (Four digit bubble display, 1981) 

Led wafer was made in 1978 by Litronix

HPDL1414 (Smart Alphanumeric display, 1999)

MSD2313 (5x7 matrix display for military applications, 1989)

(MSD2313 driver die, 1986)