Tinkering with Raspberry (and other things)


The “All-Out” Board – part 4 (Electronics)

Part three grew steadily and finally was no fun to read because of its length, so I split it again. Only to avoid “tl;dr”…


I have been talking a lot about level shifting without explaining it. This is about to change…

For a very long time electronic components like ICs, sensors etc. were working on TTL-level, meaning that they were operated by 5 Volts. As parts became more and more integrated, smaller and needed to be even more energy efficient, they began designing electronic components that were operated by 3.3 Volts, which is called CMOS-level. This did not only affect the operating voltage, but also the levels on which logical components could detect HIGH/LOW levels. It is clear that a device that is designed to run on 3.3 V will not tolerate a voltage of 5V on any of its connections. So what to do if you want to use 5V and 3.3V parts together? Right, level shifting. Continue reading