Building a LED Sign with Arduino and Pentameter Circuit

To begin with, I had to design the PCB layout carefully so that all the anodes and cathodes face the same direction. In my case, the anodes faced upwards as Soler them in place. However, this tactic does not fix the LEDs in the designated spot very well, so I heated up the solder afterwards once again and pushed a bit from the other side to get decent results. This process was repeated for every one of the remaining four letters, which took about half an hour after that. I got myself 0.8 mm silver care wire straightened out with the help of two pliers and form six bridges which jump across two holes of the stripboard. I used those around the lad eye to connect all the anodes of each row together in order to create a so-called common anode.

At the end, I soldered a wire to each cathode line and one extra wire to the common anodes, resulting in a complete LED sign. To test it out, I applied the forward voltage of this led type to the Caron anode and each cathode line, and it all seems to work without any problems. Now that we can move on to the control electronics, let's take a look at the schematic.

The main input signal will be the IC voltage of a 3.5 mm Jack, which produces maximum voltage peaks of around 1.3 volts. That is quite low if we want to distinguish them between seven threshold values for the seven rows of the LED sign. To achieve this, the signal gets amplified with a non-inverting op-amp configuration after being mixed together to mono signal and amplitude fine adjusted by a potentiometer. What we want in the end are peaks of around 8 volts in the amplified audio signal. This way, we can build up seven comparator op-amp configurations which will turn on its outputs when the voltage of the plus input aka the audio signal is higher than the voltage of the minus inputs aka the reference voltage.

To differentiate between the volume levels also known as the voltage amplitudes of the music, I used voltage dividers to create reference voltages from 1 to 7 volts. By creating these reference voltages, we successfully differentiated between the different volume levels. The output voltage bursts can then be connected to the gate of the RFD to 220 Enchanted M pads which finally turn on and off the individual rows of the LED sign.

I only built up the circuit for the upper three rows -7 six and 5 Vol on the breadboards, but nevertheless it demonstrates the principle pretty well. To continue with the project, I gathered all the parts I need for the complete control circuits and started by soldering the audio NTC Jack to the left side of the board according to the schematic.

I then added the mixing resistors, four-pin IC sockets for each quad op-amp, the mass fets with pull-down resistors, and finally all the resistors to set the amplification factor and creating the reference voltages. I try to use silver copper wire as often as possible to keep the layout neatly arranged but in the end, I was forced to use a bit of flexible wire to hook up the op-amp outputs to the gate of the M-fats.

After 2 hours of soldering it was time for the first test so I connected a 12V power supply to measure the voltage at the IC's and the reference voltages and used my oscilloscope to verify a successful amplification of my audio signal. Afterwards, I mounted a buck converter to the board hooked it up to the 12V power line set its output voltage slightly higher than the forward voltage of my LEDs connected the positive output to the common anodes and the cathode lines to the drain of the corresponding master fets.

To finish the project, I drilled 3mm holes in each corner of the two boards used 20mm spacers and M3 bolts to join them together and the project was complete with the help of the pentameter. The circuit can be adjusted to pretty much every audio signal and of course, it does look awesome especially with the lights out.

I hope you like this project and if you want to build something similar, you can find all the necessary information in the video description. Don't forget to like share and subscribe that would be awesome. Consider supporting me through Patreon in order to keep such videos coming stay creative and I will see you next time

WEBVTTKind: captionsLanguage: enever since I started creating Electronics videos there's been one repetitive question how did you make the LED sign in your intro and the answer is super simple dozens of LEDs hold in parallel and powered by a constant voltage source but since that is too easy and even a bit boring for an Electronics project video I will now show you how I created a new LED sign that features a volume unit or V meter circuit that lights up the LEDs in correspond with the loudness of the music let's get started first off we're going to need the LED sign itself for that I used the software Lo Master with a strip Oro template to create my initial design by placing 73 green LEDs on the board to form the word music then I printed it out gathered my LEDs and started placing them on the board in order to write the first lad make sure though that the anodes and cathodes all face the same direction in my case the anodes face upwards to Soler them in place I simply bent the leads and after soldering snip them off but since this tactic does not fix the LEDs in the designated spot very well I heated up the solder afterwards once again and pushed a bit from the other side this way the results look pretty decent I then repeated this process for every one of the remaining four letters which took about half an hour afterwards I got myself 0.8 mm silver carer wire straightened it out with the help of two pliers and form six Bridges which jump across two holes of the stripboard I used those around the lad eye to connect all the anodes of each row together in order to create a so-called common anodes at the end I Sol a wire to each cathode line and one extra wire to the common anodes and the LED sign is complete I tested it out by applying the forward voltage of this led type to the Caron anode and each cathode line and it all seems to work without a problem so we can move on to the control Electronics this is the schematic that I came up with looks confusing at first but let me explain the main input signal will be the IC voltage of a 3.5 mm Jack which produces maximum voltage peaks of around 1.3 volts that is quite low if we want to distinguish them between seven threshold values for the seven rows of the LED sign that is why the signal gets Amplified with a non-inverting upm configuration after being mixed together to Mono signal and amplitude fine adjusted by a potentiometer what we want in the end are peaks of around 8 volts in the Amplified audio signal this way we can build up seven comparator upm configurations which will turn on its outputs when the voltage of the plus input aka the audio signal is higher than the voltage of the minus inputs aka the reference voltage and by creating reference voltages from 1 to 7 volts with the help of voltage dividers we successfully differentiated between the volume levels also known as the voltage amplitudes of the music those output voltage bursts can then be connected to the gate of 7 RFD to 220 Enchanted M pads which finally turn on and off the individual rows of the LED sign I only build up the circuit for the upper three rows 7 six and 5 Vol on the breadboards but nevertheless it demonstrates the principle pretty well so I gathered all the parts I need for the complete control circuits and started by soldering the audio NTC Jack to the left side of the board according to the schematic I then added the mixing resistors the pent charm two four pin IC sockets for each quad op M byc the mass fets with pull down resistors and finally all the resist us to set the amplification factor and creating the reference voltages while creating the circuits I try to use silver copper wire as often as possible to keep the layout neatly arranged but in the end I was forced to use a bit of flexible wire to hook up the op amp outputs to the gate of the M fats and after 2 hours of soldering it was time for the first test so I connected a 12vt power supply to measure the voltage at the ic's and the reference voltages and used my oscilloscope to verify a successful amplification of my audio signal afterwards I mounted a bu converter to the board hooked it up to the 12v power line set its output voltage slightly higher than the forward voltage of my LEDs connected the positive output to the common anodes and the cathode lines to the drain of the corresponding master pets then I drilled 3 mm holes in each corner of the two boards used 20 mm spacers and M3 bolts to join them together and the project was complete with the help of the pentameter the circuit can be adjusted to pretty much every audio signal and of course it does look awesome especially with the lights out I hope you like this project and if you want to build something similar you can find all the necessary information in the video description don't forget to like share and subscribe that would be awesome consider supporting me through patreon in order to keep such videos coming stay creative and I will see you next timeever since I started creating Electronics videos there's been one repetitive question how did you make the LED sign in your intro and the answer is super simple dozens of LEDs hold in parallel and powered by a constant voltage source but since that is too easy and even a bit boring for an Electronics project video I will now show you how I created a new LED sign that features a volume unit or V meter circuit that lights up the LEDs in correspond with the loudness of the music let's get started first off we're going to need the LED sign itself for that I used the software Lo Master with a strip Oro template to create my initial design by placing 73 green LEDs on the board to form the word music then I printed it out gathered my LEDs and started placing them on the board in order to write the first lad make sure though that the anodes and cathodes all face the same direction in my case the anodes face upwards to Soler them in place I simply bent the leads and after soldering snip them off but since this tactic does not fix the LEDs in the designated spot very well I heated up the solder afterwards once again and pushed a bit from the other side this way the results look pretty decent I then repeated this process for every one of the remaining four letters which took about half an hour afterwards I got myself 0.8 mm silver carer wire straightened it out with the help of two pliers and form six Bridges which jump across two holes of the stripboard I used those around the lad eye to connect all the anodes of each row together in order to create a so-called common anodes at the end I Sol a wire to each cathode line and one extra wire to the common anodes and the LED sign is complete I tested it out by applying the forward voltage of this led type to the Caron anode and each cathode line and it all seems to work without a problem so we can move on to the control Electronics this is the schematic that I came up with looks confusing at first but let me explain the main input signal will be the IC voltage of a 3.5 mm Jack which produces maximum voltage peaks of around 1.3 volts that is quite low if we want to distinguish them between seven threshold values for the seven rows of the LED sign that is why the signal gets Amplified with a non-inverting upm configuration after being mixed together to Mono signal and amplitude fine adjusted by a potentiometer what we want in the end are peaks of around 8 volts in the Amplified audio signal this way we can build up seven comparator upm configurations which will turn on its outputs when the voltage of the plus input aka the audio signal is higher than the voltage of the minus inputs aka the reference voltage and by creating reference voltages from 1 to 7 volts with the help of voltage dividers we successfully differentiated between the volume levels also known as the voltage amplitudes of the music those output voltage bursts can then be connected to the gate of 7 RFD to 220 Enchanted M pads which finally turn on and off the individual rows of the LED sign I only build up the circuit for the upper three rows 7 six and 5 Vol on the breadboards but nevertheless it demonstrates the principle pretty well so I gathered all the parts I need for the complete control circuits and started by soldering the audio NTC Jack to the left side of the board according to the schematic I then added the mixing resistors the pent charm two four pin IC sockets for each quad op M byc the mass fets with pull down resistors and finally all the resist us to set the amplification factor and creating the reference voltages while creating the circuits I try to use silver copper wire as often as possible to keep the layout neatly arranged but in the end I was forced to use a bit of flexible wire to hook up the op amp outputs to the gate of the M fats and after 2 hours of soldering it was time for the first test so I connected a 12vt power supply to measure the voltage at the ic's and the reference voltages and used my oscilloscope to verify a successful amplification of my audio signal afterwards I mounted a bu converter to the board hooked it up to the 12v power line set its output voltage slightly higher than the forward voltage of my LEDs connected the positive output to the common anodes and the cathode lines to the drain of the corresponding master pets then I drilled 3 mm holes in each corner of the two boards used 20 mm spacers and M3 bolts to join them together and the project was complete with the help of the pentameter the circuit can be adjusted to pretty much every audio signal and of course it does look awesome especially with the lights out I hope you like this project and if you want to build something similar you can find all the necessary information in the video description don't forget to like share and subscribe that would be awesome consider supporting me through patreon in order to keep such videos coming stay creative and I will see you next time