Guitar tuner presentation - OCDC 2018

viernes, 10 de agosto de 2018 0 Comentarios, Dejar un Comentario
So the time has come to the end and here what i managed to do so far with the expectation to end the firmware of this awesome guitar tuner.




Here are the files for the project so far. The firmware will be ready for you to download very soon.
Hope you liked it and don't forget to vote for me XD.

Design files and part of the firmware ready to download here.

It's alive!

jueves, 9 de agosto de 2018 0 Comentarios, Dejar un Comentario
The guitar tuner its alive, it just needs some tweeks in the software ( quite a lot ), but i looks pretty good when its power on.


And if you havent noted it has the energy harvest connector on a side :P


In the next post i will upload the final Video so stay tuned XD.




The Guitar tuner almost done!

miércoles, 8 de agosto de 2018 0 Comentarios, Dejar un Comentario
The PCB has arrived so it's time to add some components and REFLOW!


So this is how it looks with al the components soldered.


And this is how it looks with a 3D printed case!


I know this a very quick post, but tomorrow i will upload more and also the presentation Video so wait for it.

Guitar Tuner PCB

martes, 31 de julio de 2018 0 Comentarios, Dejar un Comentario

The guitar tuner PCB is ready to get manufactured!


I have send all the gerber files to PCB Fabrication, so here there also if you want to make one of your own, this Open Hardware, so you can downloaded and used as you prefer to.

This PCB contains as said in previous posts a Microphone amplifier, a bunch of LEDs as user inteface, i have added 3 buttons if needed, it has a 3v rechargable battery socket and a connector for an external battery.

I think its important to say that this design uses de reverse mount LEDs of Wurth, I have never use those LEDs so i hope they look awsome in this design as it will be part of the front plate of this device.


I use Autodesk eagle in all my designs so you may download them an used with a free version of eagle if you want.


Download Files Here!

Guitar Tuner Schematic

0 Comentarios, Dejar un Comentario
Its been a while but i have now the schematic for the Low power guitar tuner explained in previous posts, so let describe you the sections

Adquisition stage:


This is the microphone amplification MAX4466 tha will be conected to oune of the inputs of the MCU to detect the tune of the guitar.

Next is the user inteface that consists of LEDs in this case will be reversed mounted LEDs.
This leds will tell the user the tone detected and tell if the guitar string needs to be tighten or a bit loosen.

 In the next post i will upload the PCB route and also the file in eagle so that anyone can DIY it.

Low energy Guitar Tuner

jueves, 31 de mayo de 2018 0 Comentarios, Dejar un Comentario
I have been searching for a simple but nice way to do this Low energy guitar tuner, so the most simple way its by detecting the frequency with a microphone (electret) with a zero-crossing detector, that will could trigger an interrupt in any micro controller for it to mesure the time between interrupts and that way find out the frequency.

Another option its to just amplify the signal from the electret and with high resolution ADC mesure and determine the frequency, the most used method in this type of simple projects is this.

There are some nice electret amplifiers circuits that makes it all very easy like the MAX4466 from Maxim.

What i have like the most from this circuit its the 5nA complete shutdown characteristic which sounds great for Low power consumption project.

I will also use Low power microcontroller, in this case a Freescale one, a KL series, which is and Ultra Low Power series according to NXP.


Regarding to a visual interface for the user i am not pretty sure of what to use, an electronic Ink display o some nice LEDs from WE, I like more the idea of the LEDs, Wurth Electronics offer some pretty nice LEDs, what i like the most of WE LEDs its that they are so so bright even if i use a high value resistor like 1K and a supply voltage of 3V3 so i guess that i could try to dimm those a little bit more and still obtain a nice visual interface to work with.




And for my surprise they happened to be Low energy consumption LEDs, with sounds awesome for this project.

I would like to make prettier version of some DIY guitar tuners that i have seen over the internet, the are huge but i liked the how they look, and i think i could do something similar but smaller.


Thats it for this post, i will try to post very soon regarding this Low energy guitar tuner. Please share and stay tuned.

Wurth Electronics Off the Clock Design Challenge 2018

viernes, 27 de abril de 2018 0 Comentarios, Dejar un Comentario


This year OCDC its comming with the Energy Harvesting Gleanergy kit and I have already receive mine, it comes with two boards, a low power processor board and the harvesting board.
This year I am going to make a guitar tuner device capable of tunnig your guitar with out the worries of have a fresh battery for it, it will be a Gleanergy device, so that means also that you will never need a wall adapter for it, think you can use it anywhere you are.

The Gleanergy kit comes with a pretty robust processor board which has an awesome e-paper display, those displays use almost nothing of the energy this kit can harvest, the processor its also an ultra los power consumption.
So, back to this year project, a guitar tuner. to make it not that complicated you will indicate which strings of your guitar you want to tune, it will indicate if you need to turn the mechanism of that string clockwise or anticlockwise, and the you can continue and repeat the steps for the next string.

This device will be very similar in aspect to a traditional electronic guitar tuner but this one will not need extra batteries of a wall-adapter.


Next week i will post my impressions regarding the KIT and make some sketches of the  Gleanergy guitar tuner. ;)