Developement of two kinds of pcbs

As I discovered that I could use and wanted to use these little propellers for sucking and floating I needed to develop a pcb with the ability to change the poles: left turn/right turn. I could use Diodes for it and I also tried it out to understand how it works, but I decided to use the h-bridge L293D recommended on different pages in internet.

I looked up in the Datasheets to learn more how an h-bridge works.

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THT Atmega328p-pu

I have never tried before to solder an Atmege328p THT type, but it was quiete easy to design it in eagle. Together with the pin headers and the THT h-bridge I had to solder a lot. The main and interesting feature for me was I had to design it on Top and Bottom Layer as I used smd resistors, capacitors and leds. That means one side is mirror-inverted. But the routing is still on one side.

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What I like in this design is the exchangebility of the chips.

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SMD Atmega328p-au

Creating a pcb with an smd Atmega328p meant for me designing and routing on a doublesided board. That was exciting, too. The difficulty was that the smd Atmega pins are a bit scattered for a combination with an ISP header and an h-bridge. I allways had at least two wires which would cut off connections of other pins. And I had to take care about the mirror-inverted connections again.

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Board production:

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Interesting to me was, that the sizes of the THT board and the smd board don't differ so much. At least no differenz. Because wiring the smd Atmega was more complicated and needed more space then the bigger but easy to wire THT Atmega.

In between I did some trials with a self-made H-BRIDGE and with L293.

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Download Eagle files

THT board:
THT eagle schematics
THT eagle board

SMD Board:
SMD eagle schematics
SMD eagle board