Summary of Assembling the 8×8 LED Board Kit
This article provides a step-by-step guide for assembling an 8x8 LED Board kit from moderndevice.com. It emphasizes checking polarity, soldering order, and testing LEDs before proceeding. The process includes installing capacitors, IC sockets, resistors, and driver chips, with specific attention to orientation and current requirements based on LED color.
Parts used in the 8x8 LED Board Kit:
- Green LEDs
- 47 ufd 25 volt electrolytic capacitors
- IC sockets
- 1k ohm resistors
- .1 ufd (104) monolithic capacitors
- Driver ICs
These are step by step instructions for assembling the 8×8 LED Board kit from moderndevice.com.
I had never played with LED displays before using this kit. I suggest reading through all the assembly steps BEFORE starting to solder because assembly order DOES matter with this kit.
Overall, this is a very simple assembly. It does have a few points which require special attention.
Step 1: Solder the LEDs
This is, by far, the most time consuming part of assembly.
Pay special attention to the polarity of each LED and make certain you have no cold solder joints.
You will be placing IC sockets over several of the solder joints and, if you get something wrong, it will make repair very difficult.
I chose green LEDs as they were the cheapest I could find. You may use other colors, but be aware of current requirements both in resistor choices and power supply.
The LEDs are placed on the NON-printed side of the board. I got ahead of myself when I first started and put a couple of rows on the wrong side of the board. De-soldering is NOT fun!
Moderndevice.com describes the following testing procedure for the LEDs. Truth be know, I just went through and closely examined the solder joints and orientation of each LED before the next step. If you skip testing, be aware you may find yourself with a complicated de-soldering project if something goes wrong.
Testing:
Clip a 470 – 1000 ohm resistor into a black alligator-clip test lead. Connect the other end of this test lead to the ground side of a 5-6V power supply. Next connect one end of a red colored alligator clip test lead to the positive, +5V side of your power supply. Clip the other end of this red, positive lead to one of the “+5V” labeled holes on the side of the 8x8LED board. Looping a piece of wire through the hole and twist it back on itself, will make a convenient terminal to which to clip the positive test lead.
Using the far end of the ground-lead resistor as a probe, carefully light up each LED in order. This can be done conveniently from the pads on which the driver chips will eventually mount.
Step 2: The capacitors
Observing correct orientation, solder in the three 47 ufd, 25 volt electrolytic capacitors.
Step 3: The IC sockets
Place the IC sockets on the board and solder just two leads. Check the positioning of the sockets. The notches on the sockets should face the capacitors.
When you are happy with the placement of the sockets, finish soldering the leads.
Step 4: The resistors
Solder in the four 1k ohm resistors. Orientation does not matter.
1k resistors are provided with the kit and used for 20mA LEDs. If you use LEDs with a different current draw, different resistors will be needed.
Step 5: More capacitors
Solder in the four .1 ufd (104) monolithic capacitors. Orientation does not matter.
Step 6: The ICs
Insert the ICs in the sockets paying close attention to correct orientation. The notch in each chip should face the capacitors. You will likely need to bend the leads a bit to get them to fit in the sockets.
For more detail: Assembling the 8×8 LED Board Kit
- What is the most time-consuming part of the assembly?
Soldering the LEDs is by far the most time consuming part of assembly. - On which side of the board should the LEDs be placed?
The LEDs are placed on the NON-printed side of the board. - How can I test each LED before continuing?
Use a 470-1000 ohm resistor connected to ground and probe each LED with a positive lead from a 5-6V power supply. - Which way should the notches on the IC sockets face?
The notches on the sockets should face the capacitors. - Do the 1k ohm resistors have a specific orientation?
Orientation does not matter for the four 1k ohm resistors. - Can I use different colored LEDs instead of green ones?
You may use other colors but must be aware of different current requirements for resistor choices and power supply. - What should I do if I place LEDs on the wrong side initially?
You will need to de-solder them, which is described as not fun. - How should I insert the ICs into the sockets?
Insert the ICs paying close attention to correct orientation where the notch in each chip faces the capacitors.
