Are the "top" and "bottom" rows of I/O pins on 0.1 inch centers so that it can be inserted into a proto Board?
If so, Can you put some ground pins inline so that they can be brought onto the proto board?
I didn't put an FTDI chip on the board, just the header to connect one to each device.
I figure with CP2102 based USB to serial adapters available for just $2-3 dollars, why put a hard to solder $4.50 FTDI chip on the board that is only used for downloading sketches? Plug on one, or connect via a header cable, unplug & go!
I sure agree with that. With the avaliblity of these super cheap USB TTL serial cable modules, why would anyone want to waste their valuble board space and added costs to place a USB serial chip or any kind onto their standalone PCB? That space if avalible could be put to much better use IMHO. Just put the needed pins to a header and move on to something more cool.
Ok,
Screw holes added on 0.1" grid. Got the 2 rows of edge connectors on 0.1" grid. Added 4 ground hole pads near the end of each row of connectors.
Tweaked traces to let ground plane fill in more. Cleaned up nameplacements.
Any other suggestions? I'm all ears.
Not that I am aware - but I am betting that having one processor do high speed data capture and writing to memory and having the 2nd move it to an SD card will be a lot easier!
No, two processors could never decide which one of them is the insane one. You need triple redundancy and then just vote on who is the insane one, 2 out 3. The highest security PLC system we used in the refinery were made by Triconex, used triple redundant processor boards, dual redundant I/O boards, dual redundant and battery backed up power supply modules. It was a beast, looked like something you would mount on a aircraft carrier and boy was it expensive! Made to mil spec standards. Funny thing is that 'baby sitting' one for ten years in my plant area I never saw a single failure alarm signifying a loss of redundancy, so all the redundacy were never called into practice.
Bob: I can't tell by looking. You board layout and EAGLE skills far exceed mine.
I am just looking at your design as a user. The question I ask myself is "what features would I want". Having the option to socket all of the chips is one of them.
Jack,
search for cp2102 on e-bay, there are tons of them.
The ones Lefty posted about last time came in bags marked BU2001-020, also 214661-01N13d03.
These are nice because the pin marked RST can be cut easily and rewired to DTR. I bought 3 of them, all were recognized by Windows Vista and it took care of downloading the driver.
Seems to be marked www.betemcu.cn, cp2102 module, B75937
doesn't look to be very usable regarding changing Reset to DTR. Would be fine for building into something needing standard comm's tho. Came with a mini-CD, didn't need it after Windows had updated for the others.
Yes. Both are microcontrollers custom programmed to do USB to Serial using internal oscillator so no crystal. Some models do use a crystal.
Like Arduino folks did with ATMega8U2 parts, using a crystal.
Cool, thanks again. I do have some of those crimp connector housings and pins, but no crimp tool. Can make them work, usually, but is slow an tedious. Looks like the pre-made wires would be a good way to go.
Neat board design! Hunkering down for a hurricane really does get the brain juices flowing. I'll be bringing my electronics to the basement tomorrow, should the need arise...
A while ago I designed a shield that had a second atmega on it, basically another arduino but in shield form, minus the FTDI. It had all of the headers from the bottom arduino broken out as well, and there was a jumper to select which arduino's serial port the FTDI was connected to. Essentially the same as yours, but modular. I imagine it could even be made stackable. A tower of arduinos! I suggested the idea and sent my design to sparkfun but they said they tried to avoid "arduinos on arduinos", which makes sense, I guess. It was worth a try! Im sure I have the schematic somewhere...