i2c LCD1602 drived by STM32F103C

 

   I wanted to use STM32F103 instead Arduno Mega for a radio with TEF6686 (see details at https://nicuflorica.blogspot.com/2020/02/radio-cu-tef6686.html).

   First, I tested classical sketch named i2_scanner but I received no device or error at all adresses beginning with 0x01.

   I search on internet and I found an interesting article STM32 I2C SCANNER. Because informations from there are too much and must read carefully, I change directly Arduino mega with STM32F103. I saw logo info on display and than nothing. I realised STM32 send correctly i2c comands to device, ut not understand messages from any device. LCD1602 (or LCD2004) need just commands, so can be used.

   I tested with LCD1602 powered from external 5V and STM32 board with 3.3V fron USB-FTDI interface or through USB using internal voltage regulator.

   Schematic is as in article from https://controllerstech.com/i2c-lcd-in-stm32/

    I made i2c LCD1602 drived by STM32F103C movie using STM32F103_i2c_LCD1602.ino sketch:

PCB from PCBWay

    A very good solution for you to have a good PCB (board) is to place an order to PCBWay.

   First, you need to made an account on PCBWay site and after that, you can search on PCBway database.

   I order PCB for three projects:
1) AVR Atmega Fusebit Doctor (HVPP)
2) Ardutester
3) Simple VGA/Video adapter
    First project, named  AVR Atmega Fusebit Doctor (HVPP) is an old project for recovery stuck AVR microcontrollers.

   You can read more details about this project in this russian article.

   Fot this project, I received this PCBs:

    Second project project 13 arduino componen tester is based on my article named Ardutester who was wited by me a 4 years ago.

   PCB made are very nice:

   Last project is for Simple VGA/Video adapter 

witch has PCB design.

   My received boards are:

4116 RAM tester

original article

   I needed a 4116 RAM tester for a vintage computer (ZX Sinclair Issue 2) and I search on internet.

   I find some article:
- http://www.ukvac.com/forum/cheap-arduino-ram-tester-cart-join-in_topic356093.html

- http://www.ukvac.com/forum/cheap-arduino-ram-tester-cart-join-in_topic356093.html

- https://www.youtube.com/watch?v=LPavFz61ifM

- https://github.com/Judder/arduino-93422tester
   My colegue, Dragos, made 4116 RAM tester using a schematic like that,

just he used Arduino Nano instead Arduino Uno:

   You can see their test in 4116 RAM tester with Arduino

Chinese Power Supply PS-1502DD (15V/2A)

original article

   I receive a cheap power supply made in China named PS-1502DD. This power supply can deliver 5 fixed stepts: 1.5V, 3.6V, 4.8V, 6.0V, 7.2V or one adjusting output from 0 to 15V at 2A (theoretically).

   After quick test with Photoframe at 4.8V and 0,63A I realise final transistor (2N3055) is put directly on steel case and is not ok.

  I remove original 2N3055 and I put 2SC5200 on aluminium radiator

   Now, I can power photoframe for long time 😁...

    Ok, I search on net informations about this power supply and I find usefull adresses:

- https://320volt.com/ps1502d-0-15v-ayarli-1-5v-7-2v-kademeli-guc-kaynagi-semasi/

- https://www.eevblog.com/forum/beginners/power-supply-transient-overvoltage/

- https://elektrotanya.com/PREVIEWS/38933510/23432455/china/dazheng_ps-1502dd_power_supply_sch.pdf_1.png

- https://www.drive2.ru/b/470457661977003315/

- https://abrazifff.livejournal.com/1979.html
- https://ru-radio-electr.livejournal.com/1221211.html
- http://forum.cxem.net/index.php?/topic/159401-бп-кит-ps-1502dd-как-доработать-регулятор-тока/
- https://www.elforum.info/topic/84699-modificare-sursa-laborator-performer-1502dd/page/2/
  The schematic for this power supply is based on "old" LM723 and classical current limiter with transistor, see 

   In article http://anyram.net/blog_ru/?p=155 you can see a god version to decrease power dissipation: use a small microcontroller to "follow" output voltage on a switching power suply instead classical transformer and bridge rectifier...