Boards for lincomatic's open source "LeafCAN"

[Deleted member 3147]

I guess I should have read a little more before posting...

I actually opened the PDE file and discovered C source code.

I found and read the thread on the 55B SOC frame.

I'd still like to look at changing my unit. I have no experience with Adurino. Could anyone point me to a page that talks about updating the unit. In particular, I noted some comment about setting fuses. Clarification on that would be appreciated.

 

[GlennD]

Setting the fuses is a one time thing. In the current distribution Lincomatic has a batch file that does it for you. If you have a working SOC then the fuses are already set.

 

[TomT]

Yeah, I started looking through the source as well to see if I can figure out why my %Gids is wrong...
It made me realize how little I originally knew and how much of that I have since forgotten! :lol:

I guess I should have read a little more before posting...
I actually opened the PDE file and discovered C source code.

 

[DaveEV]

Edit: PINs below corrected thanks to Barbouri:

I'm finally getting around to assembling my board. I'm a complete n00b at this and could use a bit of guidance with 2 issues:

I can't figure out which pins on the board need to be connected to which pins on the OBD2 connector - can someone point me in the right direction?

If you look at Chris' pic in the first post:

Black = ground = OBD2 PIN 4
Green = 12V = OBD2 PIN 16
Grey = CAN LOW = OBD2 PIN 12
White = CAN HIGH = OBD2 PIN 13

Also, if I want to flash the board to get the latest firmware (I have a USBtinyISP v3), which headers do I need to add to the board to plug the thing in? The USBtiny has a 2x3 connector which I assume will plug into the ICSP pins. It also has a 2x5 connector which I assume will connect to one of the FTDI pin areas - but the ones labeled FTDI and FTDI1 are 1x6? It looks like I may just need to use the ICSP header?

Thanks!

 

[DaveEV]

Got it wired up as above and when I plug it in the screen lights up green, but nothing else happens. Any ideas on how to proceed?

I couple pics of how it's hooked up now.

 

[Nekota]

The contrast probably needs to be adjusted. The pot to make that adjustment is small and took several different tools before I found something that moved the adjustment. You should be able to make the screen go to black squares from the no contrast.

Hope that helps.

 

[GlennD]

"The contrast probably needs to be adjusted. The pot to make that adjustment is small and took several different tools before I found something that moved the adjustment. You should be able to make the screen go to black squares from the no contrast.

Hope that helps.

_________________
Res 20Apr2010 / Ordered 27Sep2010 / Delivered 12May2011
Plates 16Jun2011 / HOV 21July2011 EVParking 30July2011"

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I agree. You should see the LeafCAN screen with no inputs.

 

[Barbouri]

I can't figure out which pins on the board need to be connected to which pins on the OBD2 connector - can someone point me in the right direction?

If you look at Chris' pic in the first post, I'd guess:

Black = ground = OBD2 PIN 4
Green = 12V = OBD2 PIN 16
Grey = CAN LOW = OBD2 PIN 14
White = CAN HIGH = OBD2 PIN 6

Ground to OBD2 pin 4 Chassis Ground
+12 Volt to OBD2 pin 16 Constant power or (pin 8 Switched power)
EV CAN-L to OBD2 pin 12 EV CAN-L
EV CAN-H to OBD2 pin 13 EV CAN-H

The EV CAN is located on the OBD2 discretionary pins and is not used in many vehicles.

Use the 2x3 ISP header with your programmer.

Greg C.

 

[DaveEV]

The contrast probably needs to be adjusted. The pot to make that adjustment is small and took several different tools before I found something that moved the adjustment. You should be able to make the screen go to black squares from the no contrast.

Thanks - that's probably it (the screen shows full green, no black at all when on), but I can't find a pot on it for the life of me.

The screen looks very similar to the Adafruit unit, but I can't find anything that looks like a pot on it on the front/sides. I can't see anything on the back, either, but that's harder to see now that the display is sandwiched to the LeafCAN board.

This is the display I bought off eBay: HD44780 1602 16x2 Yellow Screen Backlight Black Character LCM LCD Display Module

I only see 2 holes on the back that might be used for pots if you look at the pics - they are 2 pin-holes near the backlight power pins... one of those aren't it, are they? Desoldering the display is going to be a pain - how do you guys test the contrast without soldering/de-soldering repeatedly if the pot is on the back?

EDIT: Some googling reveals that I probably have to put a 10k pot on PIN-3 / VO of the LCD screen.

Looking at the board/schematic, PIN-3 of the screen goes to R3 (10k resistor) / C11 (2.2uf cap) which are not populated - I guess I'll have to solder in my own 10k pot?

Oh wait - is the pot on the LeafCAN board - the shiny metal thing with a philips head? Sure looks like a pot and is wired up to PIN-3 of the LCD. So what's up with the missing R3/C11? That must be for Arduino control of constrast?

Ground to OBD2 pin 4 Chassis Ground
+12 Volt to OBD2 pin 16 Constant power or (pin 8 Switched power)
EV CAN-L to OBD2 pin 12 EV CAN-L
EV CAN-H to OBD2 pin 13 EV CAN-H

The EV CAN is located on the OBD2 discretionary pins and is not used in many vehicles.

Use the 2x3 ISP header with your programmer.

Greg C.

Perfect, thanks Greg!

 

[DaveEV]

EDIT: Oh wait - is the pot on the LeafCAN board - the shiny metal thing with a philips head? Sure looks like a pot and is wired up to PIN-3 of the LCD.

Success



I seem to recall some discussion about CAN bus safety and proper wires that I can't find any more.

Is it OK to simply use 4ft of twisted pair ethernet? Or should I at least try to find some shielded cable? Or just buy one of the OBD2 cables with wire attached?

 

[Nekota]

The tiny pot is on the main board next to the ICSP pins and the U1 chip. I had trouble finding a tool small enough to adjust it and some magnifying lens is really helpful to see what's going on.

 

[GlennD]

The cables everyone is using has an overall shield but the only paired wires are the can buss and the other defined pair. The EV buss wires are not paired. I think the paired ethernet cable would work fine.

When I make up the cable I use shielded paired cable to come closer to the proper wiring. But I first used the unpaired cable Garygid uses and it worked fine.

 

[QueenBee]

EDIT: Oh wait - is the pot on the LeafCAN board - the shiny metal thing with a philips head? Sure looks like a pot and is wired up to PIN-3 of the LCD.

Success

I did the same thing

There was some talk in another thread about adding some chokes/etc. I have no idea if that is relevant here though.

 

[DaveEV]

The cables everyone is using has an overall shield but the only paired wires are the can buss and the other defined pair. The EV buss wires are not paired. I think the paired ethernet cable would work fine.

When I make up the cable I use shielded paired cable to come closer to the proper wiring. But I first used the unpaired cable Garygid uses and it worked fine.

Thanks, I will see if I can turn up 4-6 ft of shielded cable, if not I'll stick with the paired ethernet I'm using now.

I also need to find some small bolts/nuts to mount the thing to the enclosure...

 

[GlennD]

A real hardware store like McFadden Dale will have small screws like 4-40 in small quantities.

If you are near Disneyland, I will be happy to give you some 2 pair individual shielded Beldon cable, I have a roll with several hundred feet left, and some hardware.

 

[Barbouri]

I seem to recall some discussion about CAN bus safety and proper wires that I can't find any more.

Is it OK to simply use 4ft of twisted pair ethernet? Or should I at least try to find some shielded cable? Or just buy one of the OBD2 cables with wire attached?

I have been using 4 wire shielded USB 2.0 cable to connect my installed LeafCAN, which has worked well and is small enough to press into the crevice on the side of the dash.
The problem with the commercial OBD2 cables that I have purchased so far has been that they are very thick, due to having all pins connected. So far the only cables that I have found that have pins 12 & 13, also include all the others.
I also have been using the Sparkfun bare obd connector that TickTock had recommended back on page 5. A little extra work, but very low profile.

Greg C.

 

[garygid]

What cable have you found best to use?

Ethernet cable, with its 4 twisted pair seems
like a good choice for two CAN buses, ground,
and the switched and always-on (except during
service) "12v" DC power.

Of course, if you only need one CAN bus, some
2-pair wire would be substantially thinner.