STM8 DISCOVERY – 7segment serial link (2)

PIC 16f884 LED display posted by (C)takao21203 Using a PIC 16f884 here to test some new ideas. All the I/O bits are now freely mapable from tables. The TRISTATE is computated by the firmware.Actually these small displays are not very bright- or maybe there is a mysterious bug. STM8 circuit posted by (C)takao21203 Added some shuttle boards to the STM8 … Continue reading

STM8 DISCOVERY – 7segment serial link (1)

stm8 board posted by (C)takao21203 This is a STM8 Discovery board. I have added a PIC 16f884 and a small 7segment display. I want to program a serial link between the two controllers. Later, a display will be connected to the STM8 chip directly. However, I have some ideas to improve the 7segment decoding/driving, and it is easier to test … Continue reading

big LED matrix project update


This gallery contains 4 photos.

Here some photos from the LED matrix. All LEDs wired up now to the drive circuit. 8 controllers run at once! Next thing is to replace the defective LEDs- quite a few. Then I want to try double buffering. But this does not require many new wires. It is however some effort to write the software for this. There will … Continue reading

first test, 32×24 LED matrix, 16f59

LED matrix – 16 brightness levels! It is all done in software. 4.5 Million machine cycles/each second. Each LED processed individually…and repeating continuously. Maxing out these 16f59 chips pretty much. First successfull test today. Todo: serial double buffering. Replicate the circuit 8 times. A lot of work to do. 2. Wire up the 32 bits master controller. Write some software … Continue reading

FM transmitters

Two FM transmitters were built recently. The first transmitter is based on 7 2n3904 transistors: The second transmitter is based on 3 2sc1740 transistors: Some resistors were made adjustable especially the emitter resistor and the bias resistors. Using other transistors than the originally suggested 2n3904, this is absolutely neccessary. The schematic for the second transmitter:

switching regulator test circuit (based on LM317)

  test circuit for switching power supply. Not using a ready-made IC! It is based on PNP transistor, and coil from a CFL. Efficiency is not so good but not too bad, the transistor does not heat up, dumping 6 volts into 22 Ohms, from 20 Volts. The circuit makes some noise! And it is not the latest technology…actually based … Continue reading

new PIC projects

1. Serial LED display This display is now in a working condition. However master code only exist in assembler, not as C source. There are some external components required (a few resistors), and the displays can not be cascaded. 2. Radiation counter I am actually using one of these displays for this radiation counter. Originally Atmel/Arduino based, modified using a … Continue reading

TL494 SMPS – switching mode power supply

this is a prototype I have built for research purpose. Recently I have learned how to use MOSFET technology. 1x VGA cooler is used together with IRF9540 p-channel MOSFET. 20V/100A welding transformer is used as voltage source! With no load, DC output is about 60V. 1x 12V 50W bulb for testing. Actually today I tried a second bulb in parallel … Continue reading