Monday, September 18, 2017

25

Another split macropad

This is the largest keypad you can fit within the 100mm x 100mm PCB size. Most PCB manufacturers have special pricing for boards under 100mm square. EasyEDA and JLCPCB will produce 10 pieces for $2 (plus shipping).

This is a 5x5 matrix and has the circuitry to make a split keyboard. It uses the same Sparkfun TRRS jack as the foobar and 6lit. It is a sandwich design with M2 Spacer and screws. PCB mount switch are required as there is no plate.

The split firmware is on github. The gerber files are here.

 The top and bottom of the PCB.

 Setup as as split keyboard.

Side view showing the M2 Spacers and screws.

The bottom is a second PCB.

The underside of the main PCBs. The orientation of the Pro Micro's is critical.

Green Pro Micro

Beware the Green Pro Micro

I found these green Pro Micro's on Aliexpress. There are several sellers. Search for the part number BTE17-05. They have the same pinout as the regular blue Pro Micro's but the power circuitry is very different. For most uses it won't matter, but if you are building a split keyboard that relies on detecting voltage on the VBUS pin on the ATmega32U4 it will not function properly with the green Pro Micro. VBUS is connected directly to VCC so it always receives power. On a normal Pro Micro the slave half does not receive power on the VBUS pin and that is how it knows it is the slave. There are workarounds, by permanently assigning the left/right side as master. But it removes the convenience of swapping sides or using a side individually.

Otherwise, the build quality of the PCB is much higher than typical cheap blue Pro Micros. It was also only $2.75 each (plus shipping). At that price I would buy more. They work fine in a Gherkin and are the same green color. However, they increased the price to $3.40 each, which is about the same as the blue ones.

Side by side with a regular Pro Micro. There is no jumper J1. It is already wired as if J1 were connected.

 The bottoms of both are flat with no components sticking out.

The schematic provided by the seller. You can see the power section is much simpler than that of the regular Pro Micro.

Friday, September 15, 2017

Ordering foobar PCBs

Ordering foobar PCBs from JLCPCB.com

A complete set of 10 foobar PCBs, with top and bottom plates is $36.08 shipped to US/Canada via DHL. Other countries may be more or less. That's enough PCBs to make 5 complete split keyboards, or 10 macropads.


Ordering is not much different than ordering from EasyEDA.com. It is a little easier since it fills in the board dimensions for you after reading the gerber files.
  1. Download the gerber files from github.
  2. Go to JLCPCB.com and create an account. If you already have an EasyEDA account you can use that.
  3. Go to the shopping cart and click "Add new item".
  4. Click on "Add Gerber File" and select the foobar zip file.
  5. Since the PCB is smaller than 100mm x 100mm they have a discounted rate for up to 10 pieces. Pick 5 or 10 pieces and select your soldermask color. Changing other options will increase the cost. Why would you only order 5 instead of 10? To save weight, and reduce shipping costs. But for such a small order it probably won't make a difference.
  6. Click "Save to Cart"
  7. Repeat 3-6 for each additional PCB you want to order. The first 100mm x 100mm PCB is $2 and additional ones are $5.
  8. In the cart you can view the details of each item by expanding it.
  9. Once you have all your PCBs in the Cart click the "Checkout Securely" button.
  10. On the checkout page you fill in your address, the country determines the shipping rate. The shipping options are below the address. DHL takes about 2 days to deliver (not including the 3-4 day manufacturing time) Airmail can take up to a month.

I've only placed one order with JLCPCB so far, it is still in the production stage. Other than the ordering process I don't expect any surprises on what is delivered since it is the same company as EasyEDA.

Ironically, due to the large discount on this size of PCB, if you wanted more than 10 pieces you would need to order over a 1000 pieces to get anywhere near the same unit price.

This video goes through the process of ordering a set of foobar PCBs with plates.

Ordering foobar PCBs from JLCPCB.com from di0ib on Vimeo.

foobar 1.1 with plates

Revised foobar 1.1 PCB with top and bottom sandwich plates.

Second version of the foobar PCB. Minor changes. I have also made a top and bottom plate so that I can use plate mount switches. It can still be assembled plateless.

Uses the same firmware as the first version.

I also added WS2812b LEDs. This time the 60 per meter type and 5 fit on each half, instead of just two like on my last attempt.

The gerber files are on github.

 Switch top removable cutouts in the top plate (for Cherry and Gaterons switches, not the Outemu I am using here).

LED shine through. White PCB soldermask would probably be the best to reflect the LEDs. I may order some from JLCPCB since they don't charge extra for different color soldermask.

 12mm M2 spacers.

Connections are the same as on the previous RGB foobar. Kapton tape was used to insulate the strip from the bottom of the diodes.

Compared to the plateless foobar the plates are slightly wider.

Wednesday, September 13, 2017

6lit

Split 6 key macropads

I wanted to make a 6 key macropad that would fit within the 100mm x 100mm PCB size. Since I have been making split keyboards lately I added the same circuitry to this. I can't think of a practical use for a split macropad, but it works. It can be used singly as a regular 6 key macropad as well.

Other than the size the construction is the same as the foobar and the 16mm Split 40% keyboards. The modified firmware is on github as are the gerber files.

The PCB is smaller than 100mm x 100mm so you can get it made at a discount at EasyEDA or JLCPCB.

I am running low on the Sparkfun PRT-12639 TRRS lacks. I instead used the PJ-320D-A from LSCS.com. These have smaller plastic registration pins so need to be held in place while soldering. The Sparkfun jacks feel sturdier and I have ordered more of them.

The TRRS jacks are on the side. A cable with right angle plugs works best.
Keycaps are leftover Semiotic G20 from PMK. The rest of the keycaps are on this Gherkin.

The PCB is snapped in half for the top and bottom pieces. The rough edges need to be sanded smooth with sand paper.
All of the unused pins as well as VCC and Ground are broken out to pads.

PCB mount switches are required as there is no plate.

The bottom pieces.

6mm M2 spacers and screws. You may need thicker spacers. I used an extremely low profile socket for the right hand side.

Size comparison. Let's Split, foobar, 6lit.

Tuesday, September 12, 2017

DeathStar

A 17 key circular macropad

First circular PCB I have had made. It is under 100mm in diameter so can be had for $2 plus shipping from EasyEDA.com / JLCPCB.com. Planning to order one with black soldermask from JLCPCB.

It is running firmware from kbfirmware.com. The JSON file with the pinout is on github. The gerbers are also on github.

Installed red and green LEDs. They are controlled by a MOSFET, the same as in the Gherkin.

Top of the PCB.

Bottom of the PCB. Socket Pro Micro, MOSFET and reset switch.

Second PCB used as the base. 6mm M2 screws and spacers.

That's no moon.

JLCPCB

EasyEDA's sister PCB company

The last few orders from EasyEDA came in new packaging. It also came with a neat disposable pen.

The old boxes had some printing in Chinese. Google Translates it to this:

More of a company slogan than a brand.

I went to JLCPCB.com and it is another PCB ordering website. If you scroll down to the bottom you see the EasyEDA and LCSC logos. If you click on the forums button it goes to the EasyEDA forums. So it looks like another way to order PCB's from the same company as EasyEDA. When you login it gives you the option to login with your EasyEDA account.

The PCB order page looks different from EasyEDA but has similar options. The biggest difference I see is that you can get the $2 deal with colored PCB's. Even black is the same price. In fact there is no price change for the color of the PCB for regular size PCB's either. I hope this is not an oversite. There are also options to speed up production time for added cost.

One nice feature is that it will fill in the board dimensions after you upload your gerber files. Didn't work on a few that I tried though, so you may have to type in the dimensions manually.


The shopping cart is different and does not show the shipping costs. You have to click the Checkout button to see the total price with shipping. You can then click back to the cart, so just a few extra clicks to figure out how much shipping is going to be. On EasyEDA I would check the shipping to see if adding an extra 5 pieces would increase shipping or not, sometimes it would not and you can get a few extra boards for cheap.



The pricing models is different and seems to come out a little more. Will have to experiment more to figure out which is the better deal. You should price on both EasyEDA and JLCPCB and see which comes out cheaper.

For 10 green Gherkin PCBs + 10 green Foobar PCBs + DHL shipping the price came to:

EasyEDA $15.93 + $2 + $24.53 = $42.46
JLCPCB $21.95 + $2 + $21.09 = $45.04

JLCPCB is a few dollars more, but you can get any color PCB for the same price.

If you got the same PCB's in black instead of green at EasyEDA the price would be:
$32.34 + $24.63 + $24.53 = $81.50

Big savings if you want different colors. I hope the color pricing doesn't change in the future.

I will be placing my next PCB with JLCPCB to try out some colors. I've never ordered black before due to the added cost.

Wednesday, September 6, 2017

foobar RGB underglow

foobar with WS2812b strips added

Using the same method most people use with the Let's Split, a short strip of WS2812b RGB LEDs were added to each half of the foobar.

VCC and Ground on each strip are connected to the broken out pads on the PCB. On the Master Left Hand side the DI (input) of the strip is connected to PB6. The DO (output) is connected to the unused connection in the TRRS connector. On the Slave Right Hand side the DI (input) is connected to the TRRS connection.

I used 60 per meter LEDs for 5 on each side here.

There are only 2 LEDs per side. This is the 30 per meter type of WS2812b strip. The 60 per meter type would allow 4 LEDs to fit on each side.

 The connections. The Master is pictured on the right.

The Master side. 5v and ground connected to pads near the Pro Micro. DI connected to PB6. DO connected to the TRRS unused connection.

 The Slave side. Same power connections. DI is connected to the TRRS pad.

The firmware with RGB added is on github. The pin the RGB strip is connected to and the number of LEDs is defined in the config.h file.

Tuesday, September 5, 2017

Micropad A-Star Micro rebuild

Genovation Micropad rebuilt with Pololu A-Star Micro

This is the second Parallel Micropad 621 I have rebuilt to be USB instead of Parallel. I used a Pro Micro and jumper cables for the first conversion. This time I added a female socket header to one side of an A-Star Micro. The A-Star Micro has a different pinout than the Pro Micro. The entire left half of the board is i/o pins. I used pins 1-9 for the 9 connections to the matrix on the Micropad. The result is very clean, no jumper wires.

I cut down a larger header to 10 positions and soldered it to one side of the A-Star Micro. Only 9 pins are needed to control the Micropad. I also soldered some pieces of wire to make resetting the A-Star Micro easier. It has the same type of Arduino bootloader as the Pro Micro.

Installed on the Micropad's 9pin header. Some thick double stick tape will hold it in place.

All that is needed now is a USB cable and some cable management.


The pinout from Pololu. Pins 1 through 9 are used.

The JSON file I used on kbfirmware.com is here, as well as the compiled hex.

More information on the disassembly of the Micropad and the matrix can be seen in the original post.

Friday, September 1, 2017

Cookies 'n Cream

Oreo and a Creamsicle


Two Gherkins built with blank white PCB's and dyed plates. Oreo is dyed with Silver Grey iDye Poly. Creamsicle is dyed with Orange iDye Poly. White nylon M2 spacers and screws.