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Topic: Small Arduino+L293D board (v3) (Read 1 time) previous topic - next topic

HermannSW

Oct 15, 2015, 10:40 pm Last Edit: Oct 15, 2015, 10:51 pm by HermannSW
Two weeks ago my L293D motor controller got overloaded (not sure why) and burned. I saw a  2cm high flame(!) and a lot of smoke. Unfortunately not only the L293D got destroyed, but also the soldered IC socket of the L293D:


Resoldering the IC socket seemed not to be fun (most of the 16 pins were soldered). So I decided to create a new version of my Arduino+L293D board (the third). Discussing the idea of new board and the flame experience I learned from a colleague how to easily avoid burning soldered IC connector in case a L293D will burn again. His solution was "put L293D into a IC connector and that IC connector into the soldered IC connector". That way the soldered IC connector should not get damage in case of a fire (this is stable enough, did a successful 50km/h run in Motor Test Station today with new board):


As with the previous board I wanted to be able to use Arduino Nano as well as Arduino ProMini microcontrollers, which is no real problem because all but 2 pins from Nano are available (mostly at same position) on ProMini as well:


The ICSP header the Nano has is missing for the ProMini, and I wanted to correct that:
https://www.arduino.cc/en/Reference/SPI


This is the Fritzing diagram I came up with (did not find a IC socket symbol, used 2 female pin rows instead):


For a more detailed view you may open the file in Fritzing:
https://stamm-wilbrandt.de/en/forum/v3/MTS.3.fzz

This is the board without microcontroller pluged in (the two outer 1x14 rows of female pins allow to connect any sensor as in the Arduino Uno)::


Two pins of the Nano (of the ProMini as well) do not fit into the 2x14 IC socket (TX and Raw). That is on purpose and allows to power the micrcontroller with a female cable via Raw pin. Only 3x2 of the 5x2 pin connector are used, two for Motor voltage (typically 12V or 15V for me), and 2 pins for each of the two controlled motors:


The 3 free rows for ProMini allow to access the self-built ICSP header:


I am not good on soldering, but the board works after debugging and fixing some short-circuits. Looks a bit like spaghetti  :)


I was not able to fit the Arduino into the round pin DIP IC socket, but this simple and cheap tool did the job:


I mostly use this board in Motor Test Station until now, but for an autonomous Arduino robot as well:
https://forum.arduino.cc/index.php?topic=331722.msg2386890#msg2386890

Hermann.
stepper PT camera system:
https://forum.arduino.cc/index.php?topic=647703.0
high precision linear actuator:
https://forum.arduino.cc/index.php?topic=645745.0
http://stamm-wilbrandt.de/en/Raspberry_camera.html

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