DS18B20 Temperature sensor not recognized

Hi Gurus, I'm trying to hook up a ds18b20 temperature sensor (in fact a breakout board like this) to a old RPi (ver 1) model B, running DietPi. I am following this guide from Adafruit. The '/sys/bus/w1/devices' directory always seems to be empty.

Here

Read more…

Drawing on 8x32 LED matrix with 74HC154

How do I send a pattern into an 8x32 LED matrix? I'm using the AT89S52 microcontroller with a 74HC154 4-16 line decoder, programming in C with the Keil IDE. I've done vertical scanning, but am stumped at the next step. I will include the schematic if

Read more…