There is any way to achieve a higher ADC resolution?

[407charles]

I have a chip to convert frequency to analog voltage, I did my program and circuit and it works great, the only problem is that the resolution is about 19.5 hertz/bit. There is any way to increase the resolution? A 16 bit processor will give me about 5 hertz/bit but I know that Arduino is 8 bit processor but just wondering if there is any other way. Thanks for your help in advance.

[Bachman]

Hello!

1: Make a frequency counter with the controller (no frequency to analog error).
2: Use external ADC Chip (eg.: http://www.ti.com/product/ads1262)

[407charles]

Can you be a little more specific? Thanks for the quick response and for your help.

[Bachman]

In this post, you can find four links to frequency counters: link.

[407charles]

Hello, thanks a lot for your reply. I tried to interface with the ADC 3208 SPI communications protocol without success. I got no idea what I'm doing wrong. Once I achieve that, I will finished my project. Any help is greatly appreciated. Bye.

[407charles]

By the way, I've seen that you have use the ILI9341 display. can you tell me what microcontroller did you use? for some reason I'm not able to download your program to take a loo at it. I'm using Arduino uno but the display its not working at all, it does not display anything. I have to say that I bought it on ebay for $5.00. I will appreciate if you share with me some of your experience in this topic. Thanks a lot for your help.

[Bachman]

At this time i don't have any external ADC chip. Can you post your program? Maybe somebody will find the problem.

For ILI9341, i've used two conrollers: PIC 18F46K80 & PIC 18F46K22. The controllers can run at 64 MHz without extra components and contains 64Kbytes Program Memory. Be careful not to connect the LED pin direct to the controller! It's a bug in Flocode, already reported. On the controller, leave it unconnected, on the display, connet it to Vcc (3.3 V) across a 10 Ohm resistance. The LED pin on the display need lots of current, it's can damage the controller. Maybe the display is working but without backgrount light, you can't see anything.

[407charles]

Problem solved! I tried the ADS1115 Module with I2C communication protocol and it works perfect with a lot more resolution, 32768 bits!, compared with the 4096 bits of a twelve bit ADC. If any of you guys need more resolution for your project try this module, its cheap (less than 5 dollars) and it already has all the circuitry needed and it works like a champ! Thanks a lot for your help.

[joe nova]

Hello 407charles

Could you please post the routine you used to read ads1115?

Joe

[Benj]

Hi Joe,

This blog post might help to allow you to create the SPI commands to talk to the module.

http://www.matrixtsl.com/blog/simplifie ... c-and-spi/

[joe nova]

Hi Benj

Thank you very much for the attention, I will try to write a reading macro for the ADS1115, based on the information of the data sheet and the post that you indicated.

[407charles]

Hi, I haven't check the forum lately and I did not see your post before. Here is my program it works great!