The idea about DC and two power supplies was that it would be either DC jack or battery packs connected at the same time, and switches simply enable me to disable any power input instead of plugging them off. However I must admit that knowing me I would be very likely to forget to plug DC jack and watch my battery packs fry
OK, it could be switched by the switch in the DC connector (most, but not all have them).
When you plug in an adapter, the battery is disconnected - easy and nothing to remember
For capacitors you are absolutely right... I just noticed that it should be 1-10uF for every amp (from one of electronic tutorials) NOT 1-10uF for every miliamp... That is a huge failure from me, thanks for pointing it out.
Caps on a voltage regulator is not so-and-so-much capacity for a given current (I'm not talking about the buffer cap that should follow a transformer supply here). These are to keep the regulator from oscillating and to suppress noise.
For eg. an LM317, around 220 nF on the input and 22µF on the output is a good solution, both should be mounted as close to the regulator pins as physical possible.
The general idea behind VR2 was that I limit power supplied to servos so that I have a constant one. This would make me feel a bit more secure about my other calculations (such as current drain) and keep things more static in the circuit. I suppose this is not necessary it's just my insecurity showing up. I will go with your advice and remove it.
Don't worry, just ask if you're in doubt of how to size things
I am currently considering few microcontrollers (all of them have the same or very similar pinout so it doesn't pose much of a problem) so i didn't put the correct one on the design. The one i am most likely to use is PIC18F1320, I could not however find a footprint for it for EagleCAD.
I have made a circuit with the PIC13F20. A few connections is still missing on the board, so here is a tentative schematic:Full resolution
You cannot tell the pins used, as I didn't put it down yet, but the busses got them embedded, so it will come out right in the end.
I made it with 3 busses (in, out and program), but normally, I'd have made just one bus, as that makes the schematic cleaner. I added a reset circuit (and button) and pull up resistors too.
What rating decoupling capacitors should I get? Do you know any good tutorial about decoupling you could recommend. I did go through two already but the way in which it was explained was very chaotic for me as a beginner.
As mentioned, 220nF and 22µF is OK for most regulators. LDO regulators may be a bit more hysterical on values and you need to know the specific type and consult the data sheet - Which one are you planning to use?
I didn't notice that PRG was upside down in fairness... Just my inability to spot simple and obvious things. I am sure however that the pins are connected to the right pins on the PCI microcontroller.
Yes, as mentioned, it doesn't matte that much, it just annoys me, when I have to connect my programmer "reversed" when I make this hickup myself.
The main reason why I wanted to use LED bars, is because in my opinion it looks better I know its my first robot and it's not going to be all shiny and beautiful but I am trying to keep it neat.
Fine with me - I made a symbol for it in Eagle that shows as LED's in the schematic, on the board, it's got the "IC" layout.
With the board it's a bit more difficult (as to make a scheme for it) situation. I am using 1.6mm thick, stripboard (10cm by 7.5cm). Firstly this enables me to have as many layers as i would only want (as effectively the connections can cross each other as cables are isolated) and I have not got that far in operating EagleCAD. In fairness I am used to using computer for most things in my life. It would probably be a bit easier to use pen and paper to start with but i just feel more comfortable using computer (especially that it gives me experience with CAD software) also if I want to send some design on forum or to friend its easier. My scanner is hid deeply in my room and digging to it might be a problem
Well, I find it a waste of time laying out on a PC for stripboard (you can get CAD programs for that as well though) and smaller circuits, I don't even draw ahead when using stripboard.
If had some time and could make small changes to it I would be thankful On side note if you could also let me know what/how/why have been changed so that i can understand more behind what i did wrong and do it right next time it would be great If you dont however find time to play with it it's fine
I do it in between "chores", so it might take a bit longer.
Sometimes, I don't notice why I make a change (I just do it unconsciously, based on decades of working with electronic design), but I'll try to jot it down on the schematic and what I don't, just ask.
BTW. If you like to use the LED from the supply #2, it could be used to show whether it's running on battery or mains. And if you're gonna use rechargeables, a simple charger could be added, so it charges when on mains (with a LED to show that too).