Date: 1/22/2009
Place: Smith 249
Time In: 2:00 PM
Time Out: 4:00 PM
Objective: Today’s objective was to determine what parts were needed for the AVR guitar. Also to develop a method on how to write the program needed to light up the fret board.
Procedure: First, it was decided that a multiplexer or a decoder would be used to light a certain LED on the fret board considering 60 LED’s would be lit at a time out of the total 122 LED’s needed. Next, research was done on www.futurelec.com to determine the price of LED’s that would provide enough current out of each pin. Each pin would light up 12 LED’s at once which would sink 24mA since each individual LED output 2mA. It was decided that a transistor would be used with a 440 ohm resistor (to keep the voltage down so not to burn out the transistor) so the pins would not burn out on the board. The type of transistor that would be able to do this was a NPN 2N2222. After this, the price of 12 transistors, 12 resistors, 122 LED’s, an Atmega 128 board with the stamp, a Stratocaster guitar, and a JTAG interface (cable to download the program from computer to the board) were estimated on the futurelec website. The price came out to be roughly 300 dollars. The only thing not concluded was which type of multiplexer would be used to light up certain LED’s. There was not enough time to develop a program method today.
Date: 1/29/2009
Place: Smith 249
Time In: 2:00 PM
Time Out: 4:00 PM
Objective: Today’s objective was to develop a method on how to write the program needed to light up the fret board.
Procedure: First, a pseudo code was developed to determine the registers, ports, and pins used for inputs and outputs. It was decided that Pins 0 to 7 on Port A would be used as the first 8 inputs for notes of A, A#, B, C, C#, D, D#, E. Pins 0 to 3 on Port B would then be used for the last 4 inputs for notes of F, F#, G, and G#. The outputs were not determined because there was no conclusion on how to choose specific outputs using multiplexers. Next, it came to mind that a 7 segment LED would be used to display what note the guitar is in. The pin out for this element was provided in the laboratory upstairs but was wrong so more research would have to be done on that. With this in mind, pins 0 to 7 on port E would be used for the 7 Segment LED outputs. Finally, the initializations for the program were written.
Date: 2/12/2009
Place: Smith 249
Time In: 2:00 PM
Time Out: 4:00 PM
Objective: Today’s objective was to determine how to use Multiplexers to light up certain LED’s on the fret board.
Procedure: First, research was done on multiplexers to determine what kind would be needed. It was decided that two 4x16 multiplexers would be used because it would provide more than enough outputs for the 122 LED’s. Next, it was decided that the program would need to store the values to output to the multiplexers in EEPROM. There was research done on how to store these values there but it was not well understood. Dr. Kuyath helped to develop the part of the program for EEPROM and the initializations were written to do this. Finally, switches were researched for the inputs to the guitar and a 12 input rotary switch was decided to be used for the 12 inputs. There needs to be more research on how to use the multiplexers and how to set them up for next week.
Date: 2/19/2009
Place: Smith 249
Time In: 2:00 PM
Time Out: 4:00 PM
Objective: Today’s objective was to do more research on the Multiplexers and to write the Assembly code for the AVR guitar.
Procedure: First, more research was done on the multiplexers and it was decided that in fact they were not needed. This was because the certain notes on the guitar can be tied together and in a certain scale, five specific notes would be lit at once. Therefore if every A note, B note, C note, etc were tied together, a regular output with certain inputs would work. With this in mind, there would have to be 12 outputs depending on what the input is. Next, the outputs would be on pins 0 to 7 on Port C for the note of A, A#, B, C, C#, D, D#, E. Also, pins 0 to 3 on port D would be used for the note of F, F#, G, G#. Therefore, the program would be a lot easier than expected leaving the bulk of the project for hardware. After the program was written, a problem occurred in how to separate the fret board from the guitar and how to solder all 122 LED’s correctly.
Date: 3/05/2009
Place: Smith 249
Time In: 2:00 PM
Time Out: 4:00 PM
Objective: Today’s objective was to order the parts and come up with a plan on how to separate the fret board from the guitar neck.
Procedure: First, the parts were ordered from futurelec and the final price came out to be 200 dollars. Next, the guitar was ordered on e-bay for 99 dollars making the total 299 dollars for this project. After this, the problem of how to separate the fret board to drill holes for the LED’s arose. After much research, it was concluded that a heat gun could be used to melt the glue between the neck and the board. Then a putty knife could be used to pry the neck apart and a drill would be used to drill 122 holes. Finally, the project was well on its way and the only thing to do was wait for the parts.
Date: 3/19/2009
Place: Smith 249
Time In: 2:00 PM
Time Out: 8:00 PM
Objective: Today’s objective was to download the program to the board and check the outputs; also to separate the fret board from the guitar neck.
Procedure: First, the program was downloaded to the board and only the outputs would work. The program did not simulate correctly because the branch commands were out of reach. With this in mind, I re wrote the program in C language to shorten the program up by about two pages. Again, the program was downloaded to the board and still the outputs would work but only one input would work. I brought this up to Professor Gresser and he noticed that the other inputs were not grounded correctly. After grounding the inputs, the program worked correctly. For the next two hours, hot air from the heat gun was applied to the fret board and the fret board came off but cracked in the middle. Next, wood glue was applied and a clamp was used to keep the fret board stable. When the glue dried, twelve out of the 24 frets were drilled to fit the LED’s. The next step is to solder the LED’s and test that they work correctly.
Date: 3/26/2009
Place: Smith 249
Time In: 2:00 PM
Time Out: 4:00 PM
Objective: Today’s objective was to try and figure out the pin configurations of the 7 segment LED. Another objective was to decide how to connect the transistor to light multiple LEDs at one time.
Procedure: First, with much research and testing, only 4 out of the 8 outputs to the 7 segment LED were figured out. The only problem was that while testing the 7 segment LED, I forgot to use bleeder resistors to keep a low current so the element burned out and would no longer work. Next, the circuit for the transistor was figured out. There would be 5 volts applied to the base, the emitter would be grounded, and there would be 5 volts applied to a resistor into the LED into the collector to make the LEDs light all at once. The circuit is shown below.
Date: 4/02/2009
Place: Smith 249
Time In: 2:00 PM
Time Out: 6:00 PM
Objective: Today’s objective was to try and figure out the pin configurations of the 7 segment LED again and buy solder and wire to wire the LEDs to be tested.
Procedure: First, the pin configurations for the 7 segment LED were found and are shown below. The only problem was finding the common ground to make the element light up when 5 volts are applied. After some time, it was figured out and the 7 segment LED worked correctly when applicable. Next, I went to radio shack and bought solder and wire to connect the LEDs on the fret board. Since there was not enough research on what pins to connect with the solder, only the grounds were soldered.
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