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. ;)


OCDC - Final Post + Video

viernes, 2 de junio de 2017 4 Comentarios, Dejar un Comentario


So its time to show you the final product, the Portable Baby Bottle Warmer, in the following video I will show this PBBW Works, i really enjoyed making this device, im really glad of what i have accomplished.

The project files: ( Open Hardware )


Click here to download all the PBBW files

The video: ON THE RUSH



Still on time video



Assembly images










Thank you very much for watching, leave a comment if you liked the project.


PCB Assembly and REV-B of the board

viernes, 5 de mayo de 2017 1 Comentarios, Dejar un Comentario

The PCBs finally arrive, and it is time to test if anything went wrong, or if we need to make the Rev-B of the board, It almost works as spect it but i decided to make some changes in the board to increase the specs. This the board with all the components on their respective places.


REV-A Front face


REV-B Back Face


The new specs will be that we can light the PBBW in more tones that just the Red, Green and Blue LEDs one at a time as I put a single resistor in the common anode of the RGB LED, in that configuration just one color of each RGB LED can be turn on at the same time, but if we add a resistor for each LED we could make some color combinations, like a nice rainbow contained in our device. I have also change the form factor of the Buzzer, now it will be a SMT.

So let me show you how the new schematic looks like:


SCHEMATICS REVB

And a 3D look of the board before send it to fabrication:


So now we are ready to send the GERBER Files for fabrication, and in a week from now you will see working.