September 18, 2015 at 7:19 pm #1218
Some time ago I have decided to convert Siku John Deere 9560R to RC Model
I have four N20 motors:
Those motors are installed:
and wheels as well
Also steering servo
So it is time to start with lightsSeptember 19, 2015 at 8:48 am #1224
This is a great build, what is the little orange cap you use in the second picture? And are those tiny smd LEDs on the end of the wires in the final picture? You must have very steady hands to solder those, I tried before but my hands were very shaky and I ended up with bad solder joints which broke easily.September 25, 2015 at 1:21 pm #1247
That little orange cap is a drilled and polished LED 5mm.
If you have problem with shaking hands during soldering I have only one solution. You can buy that solution usually in half liter or one liter volume bottles. Dosing is individual thing, so some trials are necessary.
Anyway this is what I have done and in my opinion ver3 is the best one.
September 27, 2015 at 7:54 pm #1254
Those are brilliant looking beacons, how many LEDs are actually inside the beacon? Version three does look good, the difference between them is simply in the code right? If so you could include all three versions in the code and select which one you want to use with your controller, that is something I plan to include on my Massey.September 29, 2015 at 7:51 am #1256
I have 4 LED inside.
The difference is in the code, but I need do design circuit board to be installed in the roof. Also I want to use PCF8574 to reduce number of wires to 4 between arduino and the roof. For that I need more or less such a board:
I can probably remove 2 transistors and 4 resistors because for the lights I have now four (front left, front right and same for the rear lights).
For version 1 I can connect all the beacon LED into one transistor so in such case I need only three transistors in the roof.September 29, 2015 at 10:08 am #1258
That’s a good idea, a very nice way to expand your outputs. Are you planning to mount your XBee in the cab too?September 29, 2015 at 12:01 pm #1259
I was thinking about that as well, but if you look at that board there is no place. Maybe after changing transistors to SMD ones, but those are really small ones.September 29, 2015 at 12:48 pm #1261
Yes it does look like it would be difficult to include the XBee. You must be comfortable with smd soldering, I have only soldered discrete components so far but I plan to try a few smd chips at some stage. I’ll probably make a board with some TB6612FNG chips on it to make wiring to an arduino easier.September 29, 2015 at 2:00 pm #1262
There are a lot of tutorials on youtube about soldering. This is not very difficult.January 1, 2016 at 12:29 pm #1429January 3, 2016 at 7:02 pm #1437
Looks great, all those wheels would be hard to turn but man are you going to have great grip.February 28, 2016 at 12:00 pm #1597
After some trials it seems, that I cannot run 4 N20 motors using only one TB6612FNG. After some reading I know I need four. Unfortunatelly I need to use SMD ones because lack of space. The electrical diagram looks like this:
I wonder if I can reduce number of capacitors. They should be as close as possible to the TB6612FNG, but what does that mean? Do anybody have an experience with that?March 23, 2016 at 1:23 pm #1613
You should be able to drive two motors from one TB6612FNG provided you need less than 500mA continuous current per motor I think. What brought you to the conclusion you needed one per motor?
The reason you put capacitors close to the chips is because the traces introduce resistance and inductance, more so the inductance because an inductor resists change in current flow. So if for example you switch in a relatively high current load like a motor at high frequency the small inductive element of the traces resists that current flow and that can be enough to drop the voltage in that location causing weird effects on your power rails that can cause chips to reset even though back at the input the voltage appears stable. I think that is what happens and why it is considered good practice to provide bypass capacitors as close as possible to the chips. The reason you usually have different capacitor capacities of 10uF and 0.1 uF in parallel is to deal with different frequencies, a 10uF (probably electrolytic) has more capacity but wont respond as quickly as the 0.1uF (probably ceramic) capacitor so the smaller capacitance handles higher frequencies and larger cap handles voltage changes at lower frequencies.
That said we aren’t working on very sensitive electronics so you probably would get away without most of the capacitors if you are tight for space but if you have the space for them it definitely wont hurt to include them.
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