3D BAR GRAPH R DRIVER
3D BAR GRAPH R SOFTWARE

I settled on a 50.8mm (2”) diameter board with the LEDs arranged in a 270 degree arc with a radius of 18.5mm. The 3D printing process imposes a constraint on these decisions: the minimum wall thickness in the selected 3D printing process is about 1.5 to 2mm so the LEDs can be no closer to each other at their closest points than about 1.5mm. Ouch! But board space was at a premium and I wanted to add a few 7-segment displays to the graphs too so this IC was the perfect fit for the job.Īfter picking out the basic components, the next step is to decide on a board size, the number of LEDs on the board, and the radius and length of the arc that encompasses the LEDs.

Then I looked at the cost-about $20 each in single quantities. It requires very little external circuitry and has a simple SPI interface for controlling the attached LEDs.

3D BAR GRAPH R DRIVER

This driver IC can drive up to 128 discrete LEDs, sixteen 7-segment dispays, eight alphanumeric displays, or some combination in between. This LED was stocked in red (WP513IDT), yellow (WP513YDT), and green (WP513GDT) by a distributor too.Īfter searching for quite some time for a suitable driver IC, I finally settled on a Maxim MAX6954 common cathode LED display driver in a 36-pin SSOP package. This LED’s dimensions are constant throughout its height. The second LED was a 2.5 x 5 mm rectangular LED. Finding this LED in stock in green and yellow proved to problematic but I still wanted to do a display that used red, yellow, and green LEDs so I decided to build a second display with another LED too. I settled on the 625nm red version of this LED, part number WP1053IDT. The first LED was a 1 x 5 mm rectangular LED with a 2.8 x 5 mm base. I searched Kingbright’s website and settled on two possible LED candidates in three different colors. The first step is to pick some LEDs and a driver IC to drive them. Fortunately 3D printing could solve both of these problems: a 3D printed holder could hold the LEDs while soldering them and act as a separator to prevent light bleed.ġ x 5 mm LEDs, MAX6954 driver IC, and 2.5 x 5 mm LEDs.

I also did not want light from the lit LEDs to bleed into the unlit LEDs.

Soldering them by hand and keeping everything perfectly aligned, however, was going to be problem. I decided to build a board to hold a bunch of discrete LEDs arranged in a circle and at the correct angles. Unfortunately, no distributors stocked these bar graphs and I didn’t want to purchase the minimum order quantity of 500. My initial thought was to buy some pre-made curved bar graph segments and build my own board to hold them. I decided it was time to build my own LED bar graphs.

3D BAR GRAPH R SOFTWARE

I wanted to achieve a similar look, but I also wanted my gauge to be software controllable so I could change the number of segments lit in response to events in the playback of the two videos. Some other containment units used LED air pressure gauges from eBay. While building my zombie containment unit, I decided I wanted some LED displays or bar graphs to complement the containment status video running on the smaller secondary video monitor. Three different bar graphs built using Matlab, Eagle, Fusion 360, and 3D printing.

3d bar graph r