LCD problems (solved) and Firmware Pin Mapping

[Tdeagan]

[REPRAP SQUAD]

I finally got my firmware updated and finished wiring. I will be testing in the next day or so. Did you plug a thermisister into the empty 3rd extruder plug? Kf so you will need to.

[Tdeagan]

Interesting. A thermistor into the third extruder plug? I have my second extruder/heater/thermistor plugged into the first of the two connections (aka the second extruder connection set,) but nothing else but power and the ribbon cable.

Are there docs that describe the additional thermistor you're noting? Does it go into the 3rd thermistor socket? It's a two wire connection so it's hard to picture it going into the motor plug.

[REPRAP SQUAD]

Ya it goes into the 3rd extruders thermisister plug. Otherwise it tripps out and gives warnings. I believe Printrbot is going to add it to the kit. I know for the dual extruder kit production version not beta. It will be included and I would also assume it would be added to the extrdrboard kit as well.

[REPRAP SQUAD]

There are 3 videos that Printrbot posted on Twitter and 1 of them talks about it

[Tdeagan]

Thanks!!

I watched most of the second video (the parts that seemed relevant to just the Extrudrboard and LCD, but not the Printrbot stock extruder kit.). But I didn't watch the other two.

I get really impatient watching videos. They're so linear. My learning style betrays me with them. I can spend untold hours combing data sheets or reading manuals or web material, but watching a 3 minute video just kills me. I've been trying to learn Blender, but all the tutorials are videos and its like pulling teeth to sit through them. They're clearly where the world is going. Sigh.

I need to .

[Tdeagan]

I watched the videos (which was like chewing glass.)

I burned the specific firmware (Printrbot-LCD-Extrudr-Firmware) in case the latest Marlin I was using was wrong.

I'm still struggling with a critical work/no-work app note like the third thermistor thing being tacked onto the end of a video. I only stumbled across those vids, it's not like they were listed on the product page as required. Seems like that would be something you would note on the product page or in a tech note sent with the product. Whatever.

I don't have a third thermistor (I've been a thermocouple guy up to now.) But it seems like a standard resistor would fulfill the same purpose. My intertoob search says it's an EPCOS 100k NTP thermistor, which suggests that I could use a 100K resistor across the third thermistor port.

Either way, attaching my LCD still causes the system to drop the com connection, so something is not right there.

I'll try out the dummy load on the third thermistor port and report back.

thanks again.

[REPRAP SQUAD]

Ya I agree with you. Supposedly the recent changes Printrbot has made is to get a handle on this sort of stuff. So hopefully they do. Thats a big reason for my blog, is to attempt to help and clear up as much confusion as possible.

[Tdeagan]

I whipped up a 100K Ohm resistor with the proper plug and plugged it into the third thermistor port. I still couldn't get the Extrudrboard to work.

I compiled and flashed the latest Marlin firmware, it's more recent than the special LCD/Extrudrboard version, says it supports the LCD and I wanted source.

I removed the dummy load and, for lack of a better term, 'fiddled' with the Extrudrboard, watching the VDC output of the heater (with Pronterface trying to set the T1 hotend to 185C.) And it started working.

So now, I have the Extrudrboard working, pushing my #2 (T1) extruder with nothing plugged into the third thermistor port.

However, if I connect the LCD, the Printrboard goes offline and won't provide a USB connection.

Progress, but still frustrating.

[REPRAP SQUAD]

I dont have the most recent firmware. I have the one that says something like dual e /lcd hex. They may have fixed the issue. They really need to get a quality guide figured as well as a dedicated firmware guy just for pb on mac and Windows. Too confusing

[Tdeagan]

[RetireeJay]

[Tdeagan]

I'm with you. Funny you should ask that, I just spent the last 7 hours making the spreadsheet below.

This is based on the firmware at

pins.jpg

I still see potential problems with the LCD Enable and LCD RS mappings. I'm thinking they should be to 32 & 33, not 8 & 9

[RetireeJay]

[Tdeagan]

[RetireeJay]

See this thread for a link to the version I was looking at... viewtopic.php?f=22&t=4427

...and a discussion of the difficulty of finding the right file and finding the right mapping... with no solution except go back and ask the experts! (I wanna be an expert too! *sniff, pout* )

[Tdeagan]

This is convoluted stuff. I spend much of my work-life futzing with issues like this. A few choice blog posts/notices on the Printrbot website would go a long way to clearing things up.

There are a couple contributing problems, the first of which is the number of places that state something like
"This version is for supporting Printrboard The copy at is the official source as shipped by Printrbot HQ."

That may have been true at a point in the past, but is (apparently) no longer accurate. In his videos, Brooks is promoting as the official site.

The Marlin code has a gazillion forks. This is the network chart of the Printrbot site's code: You can see the fork by PxT a little ways down and by scrolling around you can see that PxT had commits as late as June 4 that haven't been committed to the Printrbot fork.

Both PxT and Printrbot were forked from Lincomatic which was forked from ErikZalm which is the top of the network (his show the terrifying number of forks out there for the unwary.)

So it's a little weird that the PxT was the official code, but it's not where the new official code forked from. You can see who/when the contributions over the last month are coming from:
Printrbot contribs:
PxT contribs: https://github.com/PxT/Marlin/contributors
Printrbot is a lot more active and has lwalkera as a contributor. This thread notes him talking about the Printrbot fork .

Here's the comparison report between the two forks we're looking at, ots of diffs:

This site helps a little on explaining the network graph. It really only displays differences in code, not similarities, so it's not really a 'who-begat-who' chart. More of a 'how different have these forks gotten from each other chart.'

Warning: I'm a SVN user who s trying to wrap my head around Github and may be terribly terribly confused.

[Thew]

FYI. I have found the LCD I bought from Printrbot had the LCD wrong.
Should be a 5v LCD, Mine came with a 3.3v LCD. This caused all kind of problems.
see viewtopic.php?f=15&t=4903

Thew

[Tdeagan]

I also responded in Thew's .

He's dead on the money. The LCD part is a 3.3V LCD (I peeled the sticker with the partnum out with a dental probe.)





3.3V , 3.0V backlight. And this is _clearly_ being powered by a 5V pin off the Printrboard.

Aargh. (and great catch by Thew!)

[lwalkera]

The USB connection disappearing is more a result of Brook just ordering the cheapest LCD he could find, not checking the specs, and ending up with 3.3V LCDs. Fortunately, the only thing different is the value of the current limiting resistor for the backlight. You can disconnect LCD backlight and stop the overheating and browning out by unsoldering the solder jumper on the back of the LCD to the right(when the front is facing you) of the pin header.

[REPRAP SQUAD]

This kind of stuff really needs to be caught early on or at least have a page with workflow notations as far as what happened, how it was fixed etc. I am a die hard Printrbot guy all the way but, if this kind of issues aren't figured out soon I feel that a lot of people will go somewhere else. Printrbot says they are going towards a more user friendly bot so I guess only time will tell. In the meantime I guess I am learning a ton just trying to do basic modifications or at least what I consider, "basic" to be. Within the next few days my belts and pullys should be here and I will start printing with the dual extruder setup so ill keep you guys updated on the progress as I will be adding an lcd after I chase down the dual e issues.

[RetireeJay]

[Tdeagan]

I'm with you on the confusion. I left a comment on the pins.h checkin that changed the pin numbers in the most recent printrbot firmware asking what abstraction layers are in play.

I not that lincomatic got frustrated on this topic and talked about it in his blog at . Both of the forks we've been discussing are forks of lincomatic's code, so we may be dealing with the very issue his blog post is talking about (or not, I'm having a _very_ difficult time sussing this out.)

I'm now digging into the core_pins.h file that lincomatic talks about. It's not in the actual firmware source, it's in the arduino-????\hardware\at90usb1286\cores\at90usb1286 subdir that the teensyduino stuff sets up.

I'll add what I find to the matrix I'm building.

[Tdeagan]

I've added the core_pins.h definitions. Clearly a lot of those are in use. One explanation for the pin numbering switching we see is the use of different def files. But I'm still not clear on which ones/when/how.

The 'key' between the different definitions is the PIN, i.e. PINA0 is what I'm matching every instance of something referring to port A, bit 0 to, wherever something refers to it.



pins.jpg

[Tdeagan]

[RetireeJay]

I understand Port A Bit 0 etc, and I can see from the schematic and from the Atmel data sheet how that maps to a physical pin on the chip. That's the kind of programming I cut my teeth on back in the day.

And I understand the concept of - and the reasons for - a level of abstraction. I have used it myself.

But you still have to have unique identifiers, don't you? It looks like you have duplicates for most of the range 0 - 9

[Tdeagan]

Got my RAMPS 1.4 LCD working with the Printrboard by making a simple patch cable out of breadboard jumpers.



Patch list looks like:
PB.1-EXP1.9
PB.2-EXP1.10
PB.5-EXP1.8
PB.6-EXP1.7
PB.7-EXP1.6
PB.8-EXP1.5
PB.10-EXP1.3
PB.11-EXP1.4
PB.12-EXP2.5
PB.13-EXP2.3
PB.14-EXP1.2

That's the $45 board working where the $65 Printrbot board didn't.

[Tdeagan]

[REPRAP SQUAD]

Quick question as lcd related things are by no means my strong part but, couldn't you buy an I2c lcd with 5v and wire it to work the same as buying a Printrbot one. I ask because I am looking for a cheap solution. I know you can buy them for less than 10 bucks and even get them with a built in sd card. Any info would be great.

[Tdeagan]

The firmware is set up to expect a 4x20 LCD (driven in 4-bit mode). I haven't looked at the other marlin options, there may be an i2c option in there, but it wouldn't be happy coming off the Printrboard ext2 pins without a lot of new code. It's also looking for a rotary encoder switch for menu selection. The LCD and the rotary encoder could be bought for as little as $15 combined and breadboarded to work just as well as the Printrbot LCD controller.

I used a standard RAMPS 1.4 LCD smart controller with a very simple patch cord. I see those on the market for as low as $40. They work exactly the same as the $65 Printrbot LCD controller.

I am addicted to the LCD and controller at this point, having that control makes printing a good bit easier for me.

[REPRAP SQUAD]

Your talking me into it....I think I might just end up getting a ramps one since I have a ramps controller also. So I take it that its about the same setup using the ramps lcd as the printrbot one..?

[Tdeagan]

Check out my post above. I used some breadboard jumper cables and figured out the patch and it works great! Not all the ramps controllers are exactly the same, but they're all almost identical. All of them should be pretty close but I'd check the schematic to make sure.

The one I have is a clone of the RepRap discount smart controller . It includes an SD card slot, but I just ignored those pins.