Gen7 build:

Hi,

Starting this up because there seems not be a thread which is about building your own gen7 from a novices perspective.

Getting good and cheap electronics was not as easy, gen6 being sold out. So gen7 looked the way to go and and didn't look too complicated.

There is how ever a lack of straight forward information on this.

I have a PCB board which needs drilling bought from ebay.

I have the electronics kit bought from the wiki.

I will be using mechanical end stops with screened wire and will see if this work OK before I over spend on my budget for this getting optical.
If anyone else would like to contribute to this feel free as it is to be open for everyone who needs help on the gen7 build.

The other threads are filled with convoluted development info which gets in the way of simply putting the electronics together. From a novices perspective of course lol.

So lets get started...

Step 1 - Drilling of the PCB is the first step so I will post when I've got that done.

I have access to a dremel set with a stand to do this.

Hello,
I've already made Gen7v1.2 successfully. just waiting for ATmega644 and pololus from Traumflug.Then snap and roll.its very easy and simple board to make by toner transfer method.thanks to Markus Traumflug for so simple design.
best of luck.
Raj

For what it's worth, and if you haven't already drilled the board, I'm going through the same process. Drilling suggestions in the video here: [monocultured.com]

Hi there guys
Im building my Gen7 board and it all seemed to be going well until i connected it to the PSU
I am using the molex disk drive connectors as i did not have a atx socket laying around
I connected it up and turned the supply on but only the bottom right green LED lit, not the orange standby one.
Is the standby led lit only when you are using ATX connector?
I started to poke around for voltages and found that the pins on the IC socket they say to check on [http://reprap.org/wiki/Gen7_Board_1.3.1#Power_Supply_Checks] were only giving 1 volt
Also the jumper to the above right of the standby LED was only giving 1 volt

i pokes around the LED resistors a little more, looking for a short, and noticed a puff of smoke (oh no) but i dont know exactly where from
I quickly switched the PSU off and tested all the resistors values with a multimeter but everything seems to be fine

Any ideas what might be going on?

Thanks
Chris

Quote

Is the standby led lit only when you are using ATX connector?

Given the power selection jumper is set right, both should light up.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

Just checked my jumper and it is set to the drive power supply option
Still only one LED is lit
However i am now getting 5v in all the correct places, strange

Do you think it would be safe to ignore the LED and carry on regardless?

My bad guys! got it working now
I had a bad bit of copper track where i had drilled a hole a little off center
One big blob of solder later and its working fine

[www.flickr.com]

Just finished building my board, all tests out fine! Just a little lost with the Bootloader!
Any tips on using a Mac OS and a USBtiny to program the ATmega? Anyone used the Arduino directly to upload the Bootloader?
Cheers

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[indieflows.blogspot.com]
[www.emakershop.com]

Hi again guys
I too am stuck at the programming stage, however i purchased my chip with the gen7 bootloader and teacup firmware allready installed [code[www.ebay.co.uk]][/code]
Also, i am not sure if i have the right type of TTL converter, it says it has a CP2102 chip

http://www.ebay.co.uk/itm/370532286388?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

I am currently hitting the "upload to IO board" button and nothing is happening...
Any advice?

Thanks
Chris

Does this section help [reprap.org] ?

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

Thanks Traumflug but i have read the whole article many times now!
After an evening of playing about with my driver board and getting nothing i thought i might try just sending data down the TTL board on a loopback (rxd connected to txd) to make sure it is working. I sent data from the arduino serial monitor and checked it came back, which it did. I then connected the TXD of the ttl board up to my oscilloscope to check i was getting a signal, which i was not. (as far as i know the TXD of the ttl board should be the one TRANSMITTING the data)
This seemed very odd as the loopback test worked. So i proceeded to connect the RXD of the ttl to my scope and sent some data which presented me with some wonderful flickering on my scopes screen!
After finding that out i connected my TTL board to my Gen7 RXD-RXD TXD-TXD (which didnt seem right) and it all sprung to life!

Does this mean that the TXD and RXD are marked out wrong on my cheap eBay TTL chip?

Anyway i am very happy i now have my board talking with the software (both replicator G and the reprap java software)

So far my motors are just clicking when i try to step them which i believe is due to incorrect motor wiring

Does anyone know how to connect my zapp automation motors to the gen7 board?
Datasheet: [www.zappautomation.co.uk]

Thanks again
Chris

Quote

Does this mean that the TXD and RXD are marked out wrong on my cheap eBay TTL chip?

... while one can read "TxD as "TxD here" or "connect to TxD" ...

Quote

Does anyone know how to connect my zapp automation motors to the gen7 board?

It's the same as with all other electronics. One coil to the left pair of the connector, one coil to the right pair. Also make sure the Enable pin on the Pololus goes low when you expect the motors to move. Measuring the Step pin requires a logic tester (or an oscilloscope), all others can be measured with a simple multimeter.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

Hi there, Chris Stubbs again
Thought it was about time i created an account on here
I see what you mean about the TTL pinout, annoying though.
We hooked the enable pin up to the oscilloscope and it was performing as expected, as well as the step pin

I thought i should make a quick video to help explain my problem better
I believe the motors are connected correctly but the StepSticks are picking up interference and preventing the motor from running smoothly
[www.youtube.com]

Thanks
Chris Stubbs

Hi,

I'm trying to build an Melden Prusa with Gen 7. Does anybody know where I can find the negative board layout of the latest version. I would like to etch my circuitboard becuase I'm used to that.
The problem is that I can't seem to find the layout.

Thanks for the help.


Maarten

[github.com]

In this archive, find production files in the release documents folder.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

Traumflug Wrote:
-------------------------------------------------------
> [github.com]
> ics/tags
>
> In this archive, find production files in the
> release documents folder.


Thanks, now I can start.

Updating my firmware on the chip seems to have improved my jumping-steppers problem
I only managed to get the firmware to go onto the chip by taking jumpers on and off until it finaly went through (with lots of timeout errors)
What is the correct jumper configuration for firmware upload?

Thanks
Chris

You mean microstepping jumpers? They don't (shouldn't) influence communications between the host and the ATmega.

You mean the power selection jumper? Plug one and only one. The one requires to get juice to the ATmega, depending on where your 5 volts come from.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

I usually select the serial power header for programming but the firmware never seems to uplaod, fidling around witht he jumpers (switching it to disc power and back) sometimes lets the firmware "go through" I am thinking i must be a step i am missing in the firmware upload process

Ok, these things are called "jumper", but there isn't really a need to change their position every five minutes. Put it in, matching your supply and leave it there. If the LED closer to the endstops lights up, the ATmega has juice and should work.

Errorneous firmware uploads can have many causes, the most often seen ones are bad solder joints and/or a non-working auto-reset. If auto-reset doesn't work -- you get an error message with "timeout" in it, you can do a manual reset. Two common opinions exist: press the reset button right before the upload starts, or a moment after. The Gen7 bootloader waits 3 seconds after a reset for an incoming firmware.

Other errors are the ones you see with other electronics as well. Like an confused FTDI driver, board mismatch, wrong baud rate (the Gen7 bootloader expects 115200 baud) and similar things. You can google for problems with Arduinos, these work just the same was as a Gen7. And you can upload the sketches coming with the Arduino IDE as well. The "Blink" sketch works, there's just no LED actually blinking

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

Great successes at last!!!
I now have fantastic smootgh running X, Y and E motors
However i am still having terrible jumping problem with my Z axis

The solution to my problem turned up here: Config

Each Pololu has a trimpot located next to the heatsink. The trimpot controls the current that is sent to each motor. Turning the trimpot counter-clockwise reduces the current to the motor, turning it clockwise increases the current to the motor.
Start by adjusting the trimpot down until your motor vibrates on the spot rather than turning cleanly. Now turn the trimpot in a clockwise direction in small increments (1 eighth of a turn) until the motors just start running. Then give the trim port a final turn of about 1 eighth of a turn and your should be good to go.

I think this is a very handy tip for anyone with jumping stepper problems

On the note of the Z axis problem, it is probably a firmware callibration issue so i will have a play around with that tommorow

Thanks again for all the help in getting me this far!
Chris Stubbs