small form factor guino

[dcb]

The announcement of the nano prompted me to contact paulb and take him up on his hardware offer, the guy at http://moderndevice.com , and see how small I could make a guino with it. The rbbb does go together in a snap, there are no extra components, and even some hints on the web page about how to trim it down further. I didn't have an led, but a Serial.println("Hello world!!") convinced me that it had gone together correctly. The rest was just figuring out where to put the pieces and route the wires so it would be as small as possible. I also made it more modular than is normal for me, since paulb sent some extra pin headers. It took some fancy wire stripping, but I can pop off the prototype board whenever I need to work on it without ungluing the rbb from the back of the lcd (just hotglue). There is a 4 pin connector on the lower left for plugging into the vehice. I didn't have any zeners handy and I didn't hookup the backlight yet, but there is plenty of room between the headers on the protoboard, might even be room for an elm chip in there . so I don't know exactly what I will do with it from here, but it is your basic mpguino lcd and buttons interface ready and waiting. The dimensions are 1.25 inches tall X 1 inch deep X 3.5 inches wide. It would be fairly easy to make it less deep with a custom board though. It would be nice if there was an LCD that didn't have the green boarder around it too , but the inexpensive ones all have it AFAIK.

P.S. Just FYI, Paulb is seriously considering making a custom board that would piggy back on the lcd and hold the zeners and processor, etc, possibly a kit with everything you need. It should make it noticably smaller in depth (if you leave off the headers) and a lot simpler to assemble.

[SVOboy]

Looks amazing...I really want to get my hands dirty with one of these.

[slogfilet]

My wife surprised me with a RBBB for my birthday! Off to Radio Shack for the extras, and I'll (of course) post any progress here.

Yeah, this thing is small... she's a keeper to realize how much these things geek me out. =)

[dcb]

That's pretty cool. Which programmer are you going to use?

[slogfilet]

Unsure. Suggestions?

[dcb]

That's the problem with the rbbb, gotta think about the programmer since it isn't built in. Well I have the "p4" pictured above, but it is serial port. There is a USB cable too but it is like $25. I actually use an iDuino as a usb programmer these days($18) but with a homemade adapter to utilize the p4 pinout for my existing creations.

More advanced options: You can slap together the parallel programmer (dig around arduino.cc). With a couple transistors you can build your own serial connection, see the lower left part of the serial arduino schematic: http://webzone.k3.mah.se/k3dacu/ardu...o_rs232_v2.png

It wouldn't be so bad to build your mpguino around the rbbb and pick up an iduino for programming purposes (iDuino - Breadboardable Arduino Clone -=- Spiffie.org) Then you will still have a duino to mess around with and an mpg gauge. But the P4 serial port interface is cheap if you have a serial port.

[wyatt]

Originally Posted by dcb

It would be nice if there was an LCD that didn't have the green boarder around it

If you really dislike the green around it, it shouldn't be that hard to make some sort of shell that would encase it (easy to take apart, for sure). It would make it look like it was professionally made, too. It may be as simple as going to a few stores with it in hand and looking for little plastic containers with clipping tops that are the correct size. Then you could cut out a hole for the USB, the power, the LCD, and the buttons. When you need to work on it, just open it up and work on it.

Also, I noticed that others were asking about programming it. Is that part difficult? I have approximately zero experience with any of this, but would like to make one if it would work with no more difficulty than the original MPGuino.

[dcb]

The only problem I have with the green border is that it makes the unit larger (hides a tiny bit more of my dashboard). I am not overly concerned with appearances, just functinality and utility. The rest of the circuit could easily hide behind the black area. I did look at a borderless 2x16 from newhaven display, but it involved smd so that rules it out from a project perspective, though anyone who knows what they are doing could make it work probably.

Programming is only difficult with the rbbb from wolfden or moderndevices. Otherwise just get a usb iDuino or freeduino or arduino and load the drivers and bob's yer uncle

[slogfilet]

dcb- could you provide a bit more detail/picture/schematic of the "shield" for your rbbb? i've got the rbbb assembled and have the extra header pins for sticking it all together, just want to double check to make sure i understand everything.

[ishiyakazuo]

Originally Posted by dcb

That's the problem with the rbbb, gotta think about the programmer since it isn't built in. Well I have the "p4" pictured above, but it is serial port. There is a USB cable too but it is like $25. I actually use an iDuino as a usb programmer these days($18) but with a homemade adapter to utilize the p4 pinout for my existing creations.

SparkFun has roughly the same USB adapter (made by them) for a few bucks less here.
But SparkFun is kind of slow sometimes -- still waiting for it to arrive.
I need to build that darn ICSP cable myself, and a board to put ATMegas into.

EDIT: Got my SparkFun adapter today, and it is TINY! It's a perfect size match for the RBBB. My only concern is that it has +3.3v marked as the input where RBBB says it's connected to +5v...

EDIT #2: Looks like SparkFun's adapter isn't a direct match -- it won't supply +5v like the FTDI cable I don't know why they didn't hook up +5v like FTDI (and what's more worrying is that they don't mention the difference!)