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2nd Ardrino Project - Newbie needs some project help
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2nd Ardrino Project - Newbie needs some project help

by ram9cc on Tue Feb 12, 2019 9:11 pm

Hi!

I would like to take a RPM/Tachometer signal from a hall sensor and read in the signal and develop software
to convert it to symbol table lookup for display entries for a OLED display ( fancy RPM gauge)

I'm new to adafrut and very new to Arduino - though i have hacked with a canbus Arduino device before I'm also a very seasoned
programmer in a number of languages and disciplines.

While i'm comfortable with the software i'm totally clueless about putting together my own kit to mange this.

I'm planning to embed everything into potting compound - device would be running off a 12V battery.

I suspect some of the hardware problems i would need to solve are

embedding USB cord ,
12V -> +USB,
embedding OLED and board,
running leads

I need some help understanding what product i need from ada fruit to get started.

It seems that these are the start:

1x - Assembled - Adafruit FeatherWing OLED - 128x32 OLED Add-on For Feather
1x - Header Kit for Feather - 12-pin and 16-pin Female Header Set
1x - Adafruit Feather 32u4 Basic Proto

I have no idea what i'm missing.


Any advise or pointers would be great. Is this enough to get started - Any suggestions about what pin is good
for reading line voltage signal etc?

I looked into SPI vc I2C and I2C i suspect would
not be too slow to show number moving up and down - but i don't know the response rate of the screen would be? 100ms ? 200ms ? 50ms?
Last edited by ram9cc on Wed Feb 13, 2019 4:57 pm, edited 2 times in total.

ram9cc
 
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Re: 2nd Ardrino Project - Newbie needs some help deciding on

by franklin97355 on Tue Feb 12, 2019 9:21 pm

I'd start with those parts and get that working first. You should look into an external power supply to keep the noise down if this is going to be in a vehicle.

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Re: 2nd Ardrino Project - Newbie needs some help deciding on

by ram9cc on Wed Feb 13, 2019 2:13 pm

Thank you Franklin.

That sounds good to me. My biggest open question is what is needed to jack a line voltage signal into the feather - is there a pin for that already?

I will look into external power supplies - This is for a motorcycle, so keeping it small and light and using the existing 12V system is a priority. I suspect there is a way to shield the device if it is sensitive to noise.

ram9cc
 
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Re: 2nd Ardrino Project - Newbie needs some help deciding on

by franklin97355 on Wed Feb 13, 2019 2:47 pm

There is no pin you can put a voltage over the 3.3-volts on. You would need to isolate the voltage from the Feather. There are several ways to do this depending on what your signal is and what you want to do with it.

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Re: 2nd Ardrino Project - Newbie needs some help deciding on

by ram9cc on Wed Feb 13, 2019 4:50 pm

franklin97355 wrote:There is no pin you can put a voltage over the 3.3-volts on. You would need to isolate the voltage from the Feather. There are several ways to do this depending on what your signal is and what you want to do with it.


Interesting - So I'll need to evaluate the signal to know more.

If the signal voltage is over 3.3v what would I need to to know more about in order to read this signal.

Thank you!

ram9cc
 
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Re: 2nd Ardrino Project - Newbie needs some project help

by ram9cc on Wed Feb 13, 2019 10:06 pm

I found this :

UBEC DC/DC Step-Down (Buck) Converter - 5V @ 3A output

It sounds like it will manage 6V-16V which is in range of a 12v battery experiencing charge from a stator on the
other side of a voltage regulator. (14.5v)

and better it seems is this

Mini DC/DC Step-Down (Buck) Converter - 5V @ 1A output - TSR12450
PID: 1065

At first i read the data sheet incorrectly. now I see that "TSR12450" is the 5V converter and "TSR 1-2433" is the 3.3V.

ram9cc
 
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