GRBLDuino Shield CNC Controller

Over the past few days I’ve been designing a Arduino Uno CNC controller shield.

My requirements were pretty simple:

  • GRBL 1.1 compatible
  • Pin compatible with Pololu DRV8825 drivers
  • User replaceable stepper motor drivers
  • Screw terminals for connections
  • E-Stop, Abort, Hold, and Resume buttons
  • Probe connection
  • Spindle PWM control
  • User selectable 4th axis function (clone or separate)
  • No SMD packages in the first version

Arduino CNC shields are pretty easy to find (and shockingly cheap) but not many are compatible with the changes in GRBL 1.1. I didn’t want a product that was out of date before I even purchased it.

My design is loosely based on the Protoneer Arduino CNC Shield. I fully support the purchase of the Protoneer product but it is hard to get in the US – available only from his eBay store.

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Electronics Repair Work and Soldering

Lately there has been much discussion about and visibility of electronics, electronics repair, and soldering/microsoldering. I want to shed some light onto the tools and techniques to answer many of the common questions out there. This won’t be an all-encompassing guide, but will evolve and grow over time.

You’re going to need some tools and many of these tools can be quite expensive. To reduce the costs a bit, don’t run out a buy all of the new tools as you may not like some and may not need others; it is much better to work for a while a see what you need and how you work (I found although I bought an iSlack opening tools, I really don’t like it or use it).

The Basics:
Soldering:
I advocate buying used tools when possible and practical (I opted to buy used soldering and hot air stations and upgrade later rather than buying cheap clones or new name-brand). Obviously, don’t buy used consumable tools (tweezers, driver bits, etc) or equipment without making sure it is a good enough deal to be worth the risk. I also advocate buying good quality tools – buy the best you can afford and buy it once. I bought a used Hakko 936 soldering station after looking at all of new offerings and the clones. I preferred the temperature adjustment knob over the digital interfaces and I didn’t want to get a clone of questionable quality for nearly the same price. Fortunately, most of the parts are available still and replacement tips are plentiful. I also purchased a used Hakko 850 hot air station after considering Quick, Aoyue, Atten, and many other stations including new Weller, Hakko, Metcal, and JBC. I was into a complete Hakko setup for under $200. If you can’t find a used name brand, the Hakko FX-951 and Quick 861DW are good new options. I only upgraded because I found a deal on a Hakko FM-203 and FM-2022 (plus more) for less than the price of the FM-2022. It didn’t hurt that selling the Hakko 850 paid for most of the upgrade.

Along with your soldering and hot air stations, you will also need solder, flux, soldering braid, and maybe solder paste. Skip the paste if you won’t be reballing ball grid array (BGA) devices or doing new surface mount device (SMD/SMT) work. I suggest either a 60/40 or 63/37 leaded solder. Lead free doesn’t flow as well, wet as nice, or melt as easily. Stick to a name brand like Kester and you will be just fine. I have various sizes ranging from .015” through ⅛”. For this type of work, a size between .015” and .062” should work fine.

To remove excess solder and clean pads, solder wick is needed. It is much easier than trying to use a solder sucker and cleans better. You will need this for just about any type of rework you do. Solder wick comes in various sizes but 3.5mm is a good generic width. It works much better if flux is applied as it lets the solder flow up the wick better.

Flux seems to be a personal preference item as there are numerous brands and formulas available. I, and many others, like the Amtech 559. Make sure you buy it from a reputable source as it is often fake on Amazon and Ebay. Extra flux will make your rework and clean up much easier and better as it provides cleaning action and allows the solder to flow. Additional flux usually isn’t needed if you are soldering properly with flux core solder wire.

Screw Drivers and Bits:
Screw drivers and bits is one area where you should spend more for quality and where you shouldn’t buy used unless you can thoroughly check out the tips. The iFixIt kits listed below are good quality and have a lifetime warranty on the bits – if they get damaged, iFixIt will replace them. Other high-quality options include Wiha, Wera, and Moody. You can get by with lower quality bits and drivers but you will feel the difference as they slip more and don’t fit fasteners quite right.

Consumables:
There are a lot of little things in this work. We’ve covered some above: solder, solder paste, solder wick, and flux. Others are tweezers, tip cleaners, adhesives (such as the double sided Tesa 61395), Kapton tape, gloves, wipes, and cotton swabs.

Although tweezers are expensive, they really are a consumable item. Once the tips get mangled, they just don’t work right and will need to be replaced. There are some cheaper options, but you generally get what you pay for. I have this cheap set, and they work but they are much lower quality.

Specialty Tools:
Some of the specialty tools may be required for certain tasks you need to do or may simply make the tasks easier. The iOpener kit from iFixIt is a step up from using hot air to loosen display adhesive. Another step up is the heat pad which holds the device at a constant temperature while work is being done. Sure, you can replace a screen using a hair dryer or heat gun, but it isn’t the right tool for the job and is risky, and takes more time.

 

Tool and Supplies List:

Powerbook Logic Board and Model Number Reference List

Here is a list of Apple Powerbook logic boards and corresponding models.

820-1372 Powerbook G4 17″
820-1441 A1046 PowerBook G4
820-1502 A1013 Powerbook G4
820-1524 A1052 Powerbook G4 17″
820-1577 Powerbook 15″
820-1600 A1095 Powerbook G4 15″ (incl. IO board)
820-1615 A1085 Powerbook G4 17″
820-1679 A1106 Powerbook G4 15″ (incl. IO boards)
820-1688 A1107 Powerbook G4 17″ (incl. IO boards)
820-1810 A1139 Powerbook G4 17″ (project Q41)
820-1810 A1139 Powerbook G4 17″ (project Q41C)
820-1875 A1138 Powerbook G4 15″ (project Q16C))
820-1940 A1138 Powerbook G4 15″ (project Q16C)

I’ve pieced this together from all over the place – please let me know if there are any errors or corrections.

iMac Logic Board and Model Number Reference List

Here is a list of Apple iMac logic boards and corresponding models.

820-1257 iMac G4
820-1381 iMac G4 15″
820-1398 iMac G4 15″
820-1501 iMac G4 17″ (project Q26)
820-1501 iMac G4 17″ (project Q26A)
820-1501 iMac G4 17″ (project Q26B)
820-1501 iMac G4 17″ (project Q26C)
820-1540 A1076 iMac G5 20″ (project Q45)
820-1540 A1076 iMac G5 20″ (project Q45A)
820-1540 A1076 iMac G5 20″ (project Q45B)
820-1550 A1065 iMac G4
820-1599 A1065 iMac G4 20″ (project Q59A)
820-1599 A1065 iMac G4 20″ (project Q59B)
820-1599 A1065 iMac G4 20″ (project Q59C)
820-1747 A1058 iMac G5 17″ (project Q45C)
820-1747 A1058 iMac G5 17″ (project Q45D)
820-1766 A1145 iMac G5 20″
820-1783 A1144 iMac G5 17″
820-1888 A1174 iMac 20″
820-1919 iMac
820-1960 iMac
820-1984 A1200 EMC2111 iMac 24″
820-2031 A1174 A1207 iMac 20″
820-2052 iMac
820-2090 A1195 iMac 17″
820-2110 A1225 iMac 24″
820-2143 2223 2347 A1224 iMac
820-2143 A1224 iMac 20″
820-2223 A1224 iMac 20″
820-2301 A1225 iMac 24″
820-2347 A1224 iMac 20″ (project K50)
820-2347 A1224 iMac 20″ (project K50A)
820-2491 A1225 iMac 24″ (project K51)
820-2491 A1225 iMac 24″ (project K51A)
820-2494 A1311 iMac 21.5″
820-2507 iMac
820-2641 iMac
820-2733 iMac
820-2784 A1311 iMac 21.5″
820-2828 iMac
820-2901 iMac
820-3126 A1311 iMac
820-3172 A1418 iMac 21.5″
820-3298 A1214 iMac 27″
820-3299 A1419 iMac 27″
820-3302 A1418 iMac 21.5″
820-3478 A1419 iMac 27″
820-3588 A1418 iMac 21.5″

I’ve pieced this together from all over the place – please let me know if there are any errors or corrections.