Stock Controller Card Connecting Limit Switches

[rseijo]

Hi, I am new to CNC and GRBL. Wondering if Limit Switches can be connected to the stock controller card? if yes, does anyone have wiring and GRBL programming instructions? Using GRBL v1.1f

The card in question is the Woodpecker CNC GRBL 0.9

Thanks! Ralph

[electrokean]

Start here: https://github.com/gnea/grbl/wiki/Wiring-Limit-Switches Although that is a work in progress - there is also a long discussion at #96 Nothing specific to the Woodpecker though

[luben111]

@rseijo Can you bring some more information about your board? Some links, schematics and data sheets in order to help you. Thanks

It looks like Arduino core with added dedicated connectors for stepper drivers.

[chamnit]

Closing because this is not a bug, but feel free to continue.

[rseijo]

Thanks so much for the quick responses!! In review of the Wiki for Wiring Limit Switches it covers Arduino Cards & Shields; not the stock board (in above image) that came with the CNC Machine. Any ideas?

Also, I have yet to locate any nomenclature, data sheets, etc. for the stock board.

[luben111]

@rseijo Until this is Arduino nano processor with Grbl you can do the following:

• measure with multimeter and find which header pins to which pins of micro controller are connected
• once you have this list we can figure out the correct end switches wiring

[electrokean]

Ralph, the only reference to this "stock board" you mention that I could find is one AliExpress seller: https://www.aliexpress.com/store/product/GRBL-0-9J-USB-port-cnc-engraving-machine-control-board-3-axis-control-laser-engraving-machine/1941516_32713561151.html This isn't really a common board, and if there is no documentation for it it will be difficult for us to assist you.

The standard grbl limit inputs are on D9 (X) D10 (Y) and D12 (Z). See https://github.com/gnea/grbl/wiki/Connecting-Grbl There are pins on the header that seem to be labelled A0-A7 and D13 - and the diagram on the above linked page tells you what those are used for. I can also see some with labels starting with X/Y/Z but I can't make out the labels clearly. At a guess I'd expect those to be the ones you need for the limits. Can you tell us what they say? Maybe a close up photo from front and back of PCB near that connector would help us. If you have a multimeter, it would be possible to use that to trace out the connections from the ATmega IC to the header pins as suggested by @luben111

All that said, this board uses a CH340 USB to serial chip, and this has been known to be the cause of communication problems for many people (data loss). I would personally recommend getting a board that is more common and well documented, such as the Protoneer shield, and an Arduino Uno to plug it into. I expect those stepper drivers on the Woodpecker board follow the standard "Pololu" pinout, so you should be able to move them across to a new shield. After all the time and cost invested a CNC, you really don't want to use an unreliable and unsupported controller, even more so as a beginner.

[BlueOrangeLive]

Hello.

The external contacts are all GND. 2 Limit-X-Axis 2 Limit-Y-Axis 2* Limit-Z-Axis A5 = Probe A4 = A3 = Coolant Enable A2 = Cycle Start/Resume A1 = Feed Hold A0 = Reset/Aboat A7 = A6 = D13 = Spindel Direction RST 5V

Limit Switch Wiring:

From another shop's view from the back of the board:

Greetings Jürgen

[luben111]

We need to know the connections between the header pins and the microcontroller.

Use a multimeter and probably a needle or pin to touch the microcontroller pins. It may take 15-20 minutes to get all connections.

[rseijo]

Kean, Luben111 and Jurgen, thanks so much for the guidance and collaboration! I thought I was going to be lost on this issue.

Jurgen, I think you have cracked the code 👍 I will try the suggested setup and report my finding.

Incidentally, I order an Arduino UNO with the CNC Shield, so I have that as an alternative if this stock board does not workout,

BTW, here is a closeup image of the stock board Front.

Thanks again!

[luben111]

@rseijo You still need to measure which pin of the header to which pin of the microcontroller is going by using simple multimeter. Set the multimeter to measure short circuit (beeps when you touch both probes). See below images describing the sequence. At the end you should get some list as: Pin1 (Xon1) - pin XX of Atmega328 Pin3 (Xon2) - pin XX of Atmega328 Pin5 (Yon1) - pin XX of Atmega328 ...... If we have this list we could draw nice diagram how to connect the limit switches.

[rseijo]

Hi luben111, I will check that out and report back findings. It will be later today; on my way out to the grocery story :-) Thank you for the detailed instructions with images, this helps immensely!!!

[rseijo]

Hi, I checked the PIN Out of the chip with the multi-meter and found that the Zen, Yen & Xen had no connection points to the Atmega328 chip. Continued checking the other pins and have identified where they reside on the chip (see below image please).

Enabled the Hard limits, boolean ($21=1) and connected a Normally Open switch on Yen. Started Candle (v1.1.7) in Jog mode moved the Y Axis, while it was moving closed the switch and the Axis stopped moving. Same results for X & Z Axis; on all 6 *en pins. Pressed Reset, Alarm appears, pressed Unlock and I am able to continue the Axis travel.

Is this the correct response and sequence to restart the travel?

[luben111]

@rseijo The end switches are maybe going to some serial resistors - see image below.

You need to find where the end switches are going, you can visually follow the wires on the PCB.

Also the enumeration of the microcontroller pin numbers is as follows (please add the pin numbers in the table where to each header pin is corresponding some controller pin).

Without populating the table above with some data we can't make the correct wiring,

[luben111]

BTW, if your current GRBL version is before 0.9j and you'd like to use the latest versions of GRBL you probably have to modify the PCB - the Z limit switch in latest versions is attached to different controller pin (compared to version before 0.9j). As I see the listed version is 0.9j so maybe there is no need to modify the board.

[rseijo]

Hi Luben111, I posted the updated diagram above and here too.

The PIN Outs for the X, Y & Z connections are on the backside of the PCB. Added 2 close up pictures.

[rseijo]

With regard to GRBL version, I am using Candle v1.1.7

[electrokean]

OK, so it looks like

• there are two pairs of header pins per axis wired in parallel - perfect if you want two NO switches
• R20/R21/R22 are 100 ohm resistors in series with each limit input (for protection)
• there are capacitors in parallel with the inputs to filter noise
• the traces from those resistors disappear under the ATmega chip

Limit pins on the ATmega should be Axis = Arduino pin name = AVR pin name = pin number via series resistor X = D9 = PB1 = pin 13 via R20 Y = D10 = PB2 = pin 14 via R21 Z = D12 = PB4 = pin 16 via R22

With your multimeter you should be able to measure the 100R resistor between those header pins and ATmega pins to confirm

[luben111]

@rseijo Now you need to make the final step and measure the connections between other end of resistors and the microcontroller as @electrokean suggested.

After that we'll create the proper wiring diagram for your board

[luben111]

The final wiring will be (first we need to confirm the connections - see above) You can use some cable housing and crimp the wires to get more professional look (these connectors will fit straight into your header) http://uk.farnell.com/multicomp/2226a-02/crimp-housing-1-row-2-way/dp/1593506

[rseijo]

Hi Kean & Luben111,
Thanks for the continued guidance! Below is updated diagram with the PIN Locations for R20/R21/R22 on the Atmega328 chip.

Luben111, the diagram with the switches is awesome. Thanks

[luben111]

@rseijo Well done! Now we have the whole puzzle: pin 13 in TQFP32 is PB1 - goes to pin15 of DIP 28 and pin 14 in TQFP32 in PB2 - goes to pin 16 of DIP 28 pin 16 in TQFP32 in PB4 - goes to pin 18 of DIP 28

This means that the wiring above is correct and you can use to connect the end switches. Also this shows that you can upload GRBL v.1.1 and everything should work.

Please let us know what was the result after connecting the end switches.

BTW, the Woodpecker board is not bad at all and I'm inclined to use it in the future for small projects.

[electrokean]

@rseijo great work - if only they labelled it better, or bothered to provide documentation @luben111 what a pity it uses a CH340

[rseijo]

Luben111, Will do! Thanks for the confirmation and all your help!!

[rseijo]

Guys, Complete and Total Success!
Connected the 4 NO switches (X & Y) and everything stops (travel and spindle) when a switch is triggered. Works perfectly! I need secure the wiring and then move on the next challenge; come up with a mounting bracket/place for the Y Axis switches that don't take up too much space.

I'm so grateful to your support and guidance. Best regards!

Ralph

[rseijo]

Call me crazy, any suggested resources of where I can source parts to make a large CNC? 1ft x 3ft Table.

[electrokean]

That's pretty open ended - there is many types of CNC, but I'm assuming you mean a gantry style. Also 1ft x 3ft isn't that large - maybe for a hobby user, but it is quite small for a business. You could start with a common Chinese machine - do a search for "6090 cnc" on ebay or AliExpress You're unlikely to get all the parts individually for much less, and there are sellers who supply the hardware without motors or electronics if you want to customise it.

[electrokean]

Also, check out cnczone.com if you haven't already - lots of build logs there.

[chamnit]

A shapeoko 3 XL is pretty close to those dimensions.

[langwadt]

@rseijo parts are just a small part of building a cnc, but I've gotten stuff from http://www.robotdigg.com they've got tons of stuff and I think very decent prices

[swarfer]

@rseijo http://www.openbuilds.com get an Ox or C-Beam kit

[cavoke]

@luben111 I'm currently having troubles with this board as well. I believe it is due to the CH340 chip. GRBL Candle does not respond, and UGS states "GRBL not finished booting". As I can tell this is indicating communication issues to which re flashing GRBL has helped other people solve this issue for other boards. As you mentioned above you could be able to flash GRBL 1.1 to this board.

Do you have any information on how to do this or any suggestions to help me achieve re flashing this board with either 1.1 or 0.9? I do have the hex files I'm just not sure what to do with them.

[luben111]

@cavoke If the USB reflashing is not working - check if drivers were installed correctly and reboot the computer. If this is not helping the only one available option is to reprogram the ATMega328P on the board. If you have AVR programmer or you can borrow it you can simply reprogram the board, not sure if the board has ISP header.

[VECKOFF]

Hi Rseijo, I have the same CNC (router + Laser) with the Woodpecker CNC GRBL 0.9, but the program is different (old version than Candle 1.1.7, GRBLCONTROL 0.8). I download and instal Candle 1.1.7 but the "control manual" don´t work Can you help me ?

Thanks

[robhiggins]

@cavoke I have the same issue with my 2418 I just received last week. The board came unflashed I believe as there is no response from the board what so ever. The RxD LED does response to send requests from the serial port, but no TxD activity at all. CH340 chip makes connection, but no response from AVR at all.

[VECKOFF]

Hi Robhigins, Do you try with the GRBLCONTROL 0.8, see: https://github.com/Denvi/Candle/blob/master/readme.md With GRBLCONTROL 0.8 my 1610 work fine

[samuelketchup]

@cavoke

I have the same machine and I'm not having the issue where it will not finish booting. Could you please upload the HEX files so I can try a reflash? If you still need help, you can get Xloader from here: http://xloader.russemotto.com/ and select the hex file, Uno(ATmega328), Com#, baud rate 115200

[pswarman]

Guys, THANK-YOU so much for all your work on limit switches and XLoader, I also have this board and have struggled with the lack of documentation. I'll now implement your design suggestions on the switches. THANKS. Paul.

[marcams]

I received my Linkpsrite CNC1610 last month and was able upgrade it with limit switches and flash the new firmware from GRBL0.9 to GRBL1.1f. Homing function is working fine now (I'm using bCNC). The new firmware was flashed using Arduino IDE and configuring the board as arduino nano. Thanks guys for the references published here! ;-)

[piggei]

I received my Linkpsrite CNC1610 last month and was able upgrade it with limit switches and flash the new firmware from GRBL0.9 to GRBL1.1f. Homing function is working fine now (I'm using bCNC). The new firmware was flashed using Arduino IDE and configuring the board as arduino nano. Thanks guys for the references published here! ;-)

Did you ignore the alert about few memory for variables? I compiled the 1.1f but I didn't send the code to my card because I read that warning...

[komradebob]

marcams,

When you compiled grbl 1.1 for the woodpecker, what board type did you use? Any other changes from the stock grbl?

Thanks!

[micha88]

I had the Problem that my GRBL Board had no Arduino Bootloader installed. So I was not able to update the Board via USB. As this Board has no ISP connector I had to flash the bootloader in a direct way (connect the pins directly on the Board). After that step I am able to flash the Firmware over USB via Arduino IDE.

[uberiain]

Hello, I have the same controller , but, when I upgrade grbl 0.9j to grbl 1.1f lost the configuration of grbl. Can anyone post the $$ parameters, please?.

I have one 1610 cnc machine .https://es.aliexpress.com/store/product/2015-New-GRBL-3-Axis-Pcb-Milling-cnc-Machine-1610-Diy-Wood-Carving-Mini-Engraving-Pvc/1941516_32553569537.html

[Brandon2255p]

I have bought the 3018 but the parameters may be the same

$0 10 (step pulse, usec) $1 25 (step idle delay, msec) $2 0 (step port invert mask:00000000) $3 5 (dir port invert mask:00000101) $4 0 (step enable invert, bool) $5 0 (limit pins invert, bool) $6 0 (probe pin invert, bool) $10 3 (status report mask:00000011) $11 0.010 (junction deviation, mm) $12 0.002 (arc tolerance, mm) $13 0 (report inches, bool) $20 0 (soft limits, bool) $21 1 (hard limits, bool); 1 Enables the limit switches; 0 Disables them $22 0 (homing cycle, bool) $23 0 (homing dir invert mask:00000000) $24 25.000 (homing feed, mm/min) $25 500.000 (homing seek, mm/min) $26 250 (homing debounce, msec) $27 1.000 (homing pull-off, mm) $100 800.000 (x, step/mm) $101 800.000 (y, step/mm) $102 800.000 (z, step/mm) $110 800.000 (x max rate, mm/min) $111 800.000 (y max rate, mm/min) $112 500.000 (z max rate, mm/min) $120 10.000 (x accel, mm/sec^2) $121 10.000 (y accel, mm/sec^2) $122 10.000 (z accel, mm/sec^2) $130 200.000 (x max travel, mm) $131 200.000 (y max travel, mm) $132 200.000 (z max travel, mm)

I am getting a get_sync() error. Did you upload it using USB or an ISP connector?

[uberiain]

Thanks , I uploaded grbl 1.1f with usb without problems.

El 27 jul. 2017 21:16, "Brandon Piner" notifications@github.com escribió:

I have bought the 3018 but the parameters may be the same

$0 10 (step pulse, usec) $1 25 (step idle delay, msec) $2 0 (step port invert mask:00000000) $3 5 (dir port invert mask:00000101) $4 0 (step enable invert, bool) $5 0 (limit pins invert, bool) $6 0 (probe pin invert, bool) $10 3 (status report mask:00000011) $11 0.010 (junction deviation, mm) $12 0.002 (arc tolerance, mm) $13 0 (report inches, bool) $20 0 (soft limits, bool) $21 0 (hard limits, bool) $22 0 (homing cycle, bool) $23 0 (homing dir invert mask:00000000) $24 25.000 (homing feed, mm/min) $25 500.000 (homing seek, mm/min) $26 250 (homing debounce, msec) $27 1.000 (homing pull-off, mm) $100 800.000 (x, step/mm) $101 800.000 (y, step/mm) $102 800.000 (z, step/mm) $110 800.000 (x max rate, mm/min) $111 800.000 (y max rate, mm/min) $112 500.000 (z max rate, mm/min) $120 10.000 (x accel, mm/sec^2) $121 10.000 (y accel, mm/sec^2) $122 10.000 (z accel, mm/sec^2) $130 200.000 (x max travel, mm) $131 200.000 (y max travel, mm) $132 200.000 (z max travel, mm)

I am getting a get_sync() error. Did you upload it using USB or an ISP connector?

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[dneuman1]

@ micha88 can you detail what you had to do ... I am having the same issue

"I had the Problem that my GRBL Board had no Arduino Bootloader installed. So I was not able to update the Board via USB. As this Board has no ISP connector I had to flash the bootloader in a direct way (connect the pins directly on the Board). After that step I am able to flash the Firmware over USB via Arduino IDE."

[Brandon2255p]

@dneuman1 I can help you. I literally just updated my board from 0.9 to 1.1f in the last hour. I would really recommend that you do not even attempt this if you do not have very accurate soldering skills, knowledge of arduino and either a spare arduino or an ICSP.

You will need to solder 4 wires to the Atmega328. These will go to MOSI, MISO, SCK and Reset. Then use your ICSP or arduino as an ISP to program it. I chose to just upload the software and not to burn a bootloader.. but it may have been a good idea to burn a bootloader!

I can provide pictures if you need more assistance

[dneuman1]

@Brandon2255p Great! I repair classic arcade PCBs as a hobby, so I have excellent soldering skills and spare boards

[Brandon2255p]

@dneuman1 Just a couple pics that I took which show you my dodgy setup that actually did not short anything out:

[komradebob]

I don't see anything dodgy about that...Well the clear tape maybe. :)

On Fri, Jul 28, 2017 at 4:38 PM, Brandon Piner notifications@github.com wrote:

@dneuman1 https://github.com/dneuman1 Just a couple pics that I took which show you my dodgy setup that actually did not short anything out: [image: img_20170728_211732] https://user-images.githubusercontent.com/8842924/28735340-fdcae66e-73e4-11e7-9536-f86acce42a95.jpg [image: img_20170728_211711] https://user-images.githubusercontent.com/8842924/28735341-fdcb5bd0-73e4-11e7-818d-e7f98df4652b.jpg

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[dneuman1]

@Brandon2255p - Cool! ... thanks for posting these pics of your setup