Howdy everyone! I'm working on my first "real" project, and I'd like to lay out a small board to time some events from an input buffer chip (looking at a car's primary ignition coil to get engine speed - something I'm familiar with from other projects), and to open/close a "relay" based on engine speed and some logic. I've got code working on a standard UNO SMD board.
Now looking to build a few of these, I'd like to know the feasibility of building a 2-sided board which supports the 328P.
I'd also like to better understand what my programming options are (header on the board, serial coms chip like FTDI, or perhaps finding a small non-SMD chip to program then socket in. I could probably go with something slower if need be, but my next project will likely need more computational power so I'd rather learn this all now.
Any advice, or is this all covered in some "So you want to build hardware" pamphlet?
I think the best pamphlet is a schematic. Look up the schematic of Sparkfun ProtoSnap Pro Mini. If you build a board based on the Pro Mini, it is a pretty much minimal Arduino. The ProtoSnap is interesting, because it is essentially a Duemilanove until you snap it apart, and then it becomes a Pro Mini with separate FTDI interface. You program it through the FTDI interface, but you don't need the FTDI interface to remain a part of the project after you program it.
Others will probably agree that you should probably just consider using a Pro Mini in your finished project. It sure is convenient and cheap.
AbeFM:
I'd like to lay out a small board to time some events from an input buffer chip (looking at a car's primary ignition coil to get engine speed - something I'm familiar with from other projects), and to open/close a "relay" based on engine speed and some logic. I've got code working on a standard UNO SMD board.
Now looking to build a few of these, I'd like to know the feasibility of building a 2-sided board which supports the 328P.
Overall bad idea.
The UNO board is essentially a toy, but for actual implementation of designs in small production, just purchase Pro Minis (really cheap on eBay) and use them as "daughter" boards to a PCB which then may not even need to be double-sided. You use the pin headers to connect - soldered - the daughter board to your PCB and you have a header on the end of the Pro Mini to connect a programming adapter (avoid FTDI).
In fact, you can if necessary, place components under your Pro Mini daughter board for maximum density. It really makes no sense to replicate the Pro Mini yourself.
The UNO board is essentially a toy, but for actual implementation of designs in small production, just purchase Pro Minis (really cheap on eBay) and use them as "daughter" boards to a PCB which then may not even need to be double-sided. You use the pin headers to connect - soldered - the daughter board to your PCB and you have a header on the end of the Pro Mini to connect a programming adapter (avoid FTDI).
In fact, you can if necessary, place components under your Pro Mini daughter board for maximum density. It really makes no sense to replicate the Pro Mini yourself.
I both agree and disagree. to get all the bugs worked out, absolutly use the daughter card concept.
if this is for fun, then all is good. if you plan on going commercial, then having the board made with the processor on it makes the end result professional.
Where I can, I use a sheild. like SD card and RTC.
where I need, I have boards made and use prom carriers as the headers. much less expensive and much lower profile.
my test unit has an RTC a NANO and a SD card.
I did not like the e-bay mini's as every seller changes the layout and pinout from lot to lot also, pins A4 ad A5 are not on the headers but inboard. this is because they are typically used for the I2C bus.
dave-in-nj:
if you plan on going commercial, then having the board made with the processor on it makes the end result professional.
I would - arbitrarily - call that at quantity 100.
dave-in-nj:
I did not like the e-bay mini's as every seller changes the layout and pinout from lot to lot also, pins A4 ad A5 are not on the headers but inboard. this is because they are typically used for the I2C bus.
Well, there are two or maybe three designs that I have come across, but I doubt many more. The "inboard" pinouts matter only in relation to a solderless breadboard but for that, unlike a PCB where you merely design for it, you just mount the pins upward and use "Dupont" connectors.
A Pro Mini would not be the only component where it might be wise to have the inventory on hand before getting the boards made.
Thanks everyone! Guess I had notifications turned off, I just saw this all.
Definitely checking out the Pro Mini.
How is the regulator on the nano (MIC5205)? Can you realistically use this in an automotive environment (older cars), or in practice is more power filtering recommended?
