My 1st non-breadboard circuit (shield)

I know..a lot of you good folks could solder before you could walk and probably sleep with a soldering iron under your pillow (hope you remember to turn it off..hehe), so here is this guy in his 30s bragging about his first circuit. Pathetic.

However soldering is a major challenge to me and actually the main reason I didn't get started with robotics years ago. It's just not easy for my unsteady hands. So I'm very happy to declare that I just finished my 1st working non-breadboard circuit. It's a motor+servo shield for my Arduino.

It has an L293D H-bridge chip, plugs into my Arduino and provides easy plug and play connectors for 2 DC motors, 2 servos and an external power source. Here are some photos. I know it ain't pretty but it's mine and it WORKS :)

Good job m8. You might want to "stabilize" the shield by adding some pins on the other side (to go into the analog and power headers of the arduino). Anyway, kudos on your first soldered creation!

Thanks!

Good job m8

You're just saying that cause you can't see the other side of the board where I did the soldering :D It's messy. I made a lot of mistakes and spent more time doing damage control than doing the actual soldering. Amazing that it works at all BUT it does!!

You might want to "stabilize" the shield by adding some pins on the other side

This board isn't big enough to reach the other side and it was my idea to make a mini shield. However I plan to stabilize it with a screew between the Arduino and the shield. There is a screew hole on the Arduino near the rx/tx pins. But I don't have a drill to make a matching hole in the shield so it will have to wait.

I might add that this shield is for a simple wheeled robot that is almost done now. I purposefully left some space on the shield near the rx and tx pins cause I plan to add a bluetooth OR an RF module later on.

BTW I solved the problem with the weird spacing between digital pin 7 and 8 by simply getting an extra long pin header and bending the legs to fit the Arduino. Quite a hassle and I must admit that I felt like slapping the designer of Arduino a few times in that process, but in the end it worked.

I'm planning a 2nd shield for a walking robot. It will have 12 servo connectors, a shift register, 1 or 2 multiplexer plus a shunt/sense resistor for EACH servo (so I can measure the current draw of ditto in realtime). It will be connected to the analog in's as well. I hope I find a better method of dealing with the spacing issue before that :-?

PS: If anyone knows of a good way of making holes in protoboards WITHOUT a proper drill please let me know...

Excellent work... it might be messy but it's inspiring.

Btw... I'm 30 and didn't even know what a breadboard was till last month.

Glad to be of inspiration :)

And don't worry, we still have time to catch up...

Your post reminded me of mine

http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1255204188

and I'm 30 too ;D

Yeah .. although yours is somewhat more advanced than mine. There are NO components on mine except the L293D chip and the connectors. I soldered a cap directly on the DC motors between the terminals as suggested here. It seems to work fine.

Anyway good to know I'm not the only one who had a late start into the world of microcontrollers and electronics :)

I would put a 0.1uF cap across the terminals of the L293D as well. That made a big difference for my setup as far as noise filtering.

OK?! You have a 0.1uF cap between the terminal BOTH near the motor AND near the L293D? Seems kinda redundant. Besides in the polulu article I linked to above they recommend soldering it as close to the motor as possible. And for greater noise suppression they recommend soldering caps from each terminal to the motor casing. But I may try your setup instead if I start getting noise problems...

I’m planning a 2nd shield for a walking robot. It will have 12 servo connectors, a shift register, 1 or 2 multiplexer plus a shunt/sense resistor for EACH servo (so I can measure the current draw of ditto in realtime). It will be connected to the analog in’s as well. I hope I find a better method of dealing with the spacing issue before that Huh

PS: If anyone knows of a good way of making holes in protoboards WITHOUT a proper drill please let me know…

I want to measure current with a shunt resister also, max current about 2 amp’s. I would like to know/see your value’s for the shunt and the code to convert the data. I am new to C++

In a pinch use a nail to drill a hole. Cut off the head and chuck it up.
Put a piece of wood under the board so you do not break out the bottom of the board

Aniss1001,

They are dirt cheap so a little redundancy doesn't hurt ;)