Monthly Archives: February 2018


My Glowforge finally arrived this week. I pre-ordered it in October 2015 so it took a little over two years of waiting to finally get it.

I designed and printed the obligatory escutcheon for the print button. I chose to name my Glowforge Scotty in honor of James Doohan. His character was my inspiration for becoming an engineer in the first place so I felt it was fitting.

The escutcheon after being printed.

The escutcheon after removing the tape covering.

A few thoughts on the Glowforge interface.
The interface and workflow will take a bit of getting use to but I think it will be fine once I’m more familiar with it. At first I was getting frustrated as I created a PNG image to scale. When I imported it, I thought it was too small until I realized the scale is in inches not mm. Once I realized my error, I looked for an option to change it but could not find one. I attempted to find a way to scale it to the correct size but there is no option to type in the size or view the exact measurement. It is necessary to guess what size it is by looking at the ruler on the screen which is not very accurate. What I ended up doing was using the 1:1 scale printout and placing it in the Glowforge so I could attempt to scale it correctly. Once I did that, I could not figure out how to do cuts where I wanted them. I did some reading and found that an SVG is needed for cuts. I then used Inkscape to create an SVG from a modified image with only the cuts. This worked and I was able to scale it exactly. I then created another PNG file with just the engraving and uploaded both files. I still needed to scale the engraving but that was easy and not critical. Once everything looked good, I pressed the print button. The Glowforge performed the cuts but not the engraving. I then removed the cut image and clicked print again. This time the engraving was done. On my next print, I will need to see what I did wrong here so I do not make that mistake again.

Overall it was easy to use the Glowforge but I do have a few concerns. Firstly, a desktop application to prepare the print would afford a better setup experience. Secondly, it is not possible to print if your network connection is down for any reason or if Glowforge goes out of business. While it is nice to use a device this way, it does leave users vulnerable to the existence of the company and the health of the web servers.

The original PNG file I created.

A modified PNG for the cuts. This file could not be used for the cuts as PNG files may only be used for engraving. I needed to convert this file to SVG using Inkscape.

The modified PNG for the engraving.

Overall, I’m pleased with the Glowforge. I just hope that the company and the web-service run well for many years to come so I may continue to use the Glowforge.

BTW: The size of the escutcheon is 119.903 x 119.903 mm. I was not able to upload the SVG for the cuts so if you decide to use the PNG, you will need to convert it to SVG and resize it.

All Electronics LCD-101 (256×128 LCD) with Arduino

All Electronics has a rather large LCD display which will work great in a Jeopardy! like game that I am building. The display should be rather easy to use with an Arduino or Raspberry Pi but searching for Arduino or Raspberry Pi projects using the display turns up very few details. Fortunately the SED1330F datasheet is fairly well written. With some experimentation, it is possible to figure out how to get it to work. Especially helpful is table 32 in section 9.1.2. Some of the parameters need to be changed but it is a great example of how to get the display to work.

Here is a very short video of the LCD running from an Arduino UNO. The video starts with the display showing the result from the test2 function from the sample code below. I then upload the code again with the test2 function call commented out and the testDataSheetSection9 function call uncommented.



I plan to post more information as the project progresses. I do want to mention a few things that I found out in regards to the display.

  • You may wonder if the HG25504 is single or dual-panel display. It is a one panel display. This becomes obvious when you look at the ICs on the back of the display. The columns are driven by four HD66204FC Dot Matrix LCD column driver with 80-channels. If each column was used on these chips, they could drive 320 columns. This is 64 more columns than the display has but no where near 512 columns which would be required for a dual-panel configuration.
  • Included ICs and function
    • HD66204FC (Qty 4) Dot Matrix LCD column driver with 80-channels
    • HD66205FC (Qty 2) Dot Matrix LCD common driver with 80-channels
    • SED1330F (Qty 1) LCD Controller
    • HY6264A (Qty 1) Static RAM (8K bytes)
    • KA324D (Qty 1) Quad Operational Amplifier
  • Vo (LCD Contrast Voltage) – You really do need to apply at least -10V to Vo in respect to ground. There are some posts regarding this display stating that tying it to ground is enough but it is not. I had applied a negative voltage but was only seeing something when Vo was near ground potential. I was able to initialize the LCD but could not see anything displayed. I knew the screen was initialized because with Vo being close to ground potential, I saw one or more lines on the LCD when it was initially powered up. When I initialized the LCD, the line(s) were gone. I was getting frustrated as I could not display anything on the screen after initializing it. When I finally used a different power supply, I could see that I had been doing things right.
  • Power Requirements (You may have different results)
    • LCD Contrast (-10.5VDC @ 3.5mA)
    • LCD Logic (5VDC @ 10mA)
    • Arduino Uno (5VDC @ 10mA
  • The SED1330F supports 8080 and 6800 family processors. This matters as the LCD is wired for one or the other and the control lines change function based on the wiring of the LCD. Section 2.4.3 of the datasheet specifies that SEL1 and SEL2 determine the operation. Both SEL1 and SEL2 are connected to ground on the LCD therefore it is operating in 8080 mode.