Atmega328p with ADXL345

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re4mat0r
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Joined: Thu Nov 05, 2015 9:18 am

Atmega328p with ADXL345

Post by re4mat0r » Mon Jun 20, 2016 11:50 pm

Hi. I am trying to build a custom sensor board to connect several sensors to Atmega328p microcontroller.

If anyone can help me and look to the schematics, maybe point some errors, I would really appreciate it.

It is ADXL345 connected to Atmega328p, also a slot for DS18B20 digital thermometer. I have several pads connected to control LEDs with PWM and one pad for interrupt input.
Attachments
SensorBoard Scheme.png
Schematics

skimask
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Re: Atmega328p with ADXL345

Post by skimask » Tue Jun 21, 2016 5:44 am

No decoupling caps.
I ignore "one post wonders".

mattylad
Posts: 231
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Re: Atmega328p with ADXL345

Post by mattylad » Sat Jun 25, 2016 2:28 am

Where does "Res" go thats on R2? I cannot see another reference to it.

davep238
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Location: Burke, VA, USA

Re: Atmega328p with ADXL345

Post by davep238 » Sat Jun 25, 2016 10:41 am

mattylad wrote:Where does "Res" go that's on R2? I cannot see another reference to it.
RES goes to C2. According to its datasheet,the ADXL345 can't have more than 3.9v max on its pins. The micro is a 5 volt part, so its output HI voltage (logic '1') will be 5 volts. The ADXL345 will be damaged or destroyed by connecting its pins directly to the micro. Can you lower the micro's power supply to 3.3volts?
-Dave Pollum
programmer / digital designer
PCBs designed for low cost

mattylad
Posts: 231
Joined: Sat Sep 25, 2010 3:49 pm

Re: Atmega328p with ADXL345

Post by mattylad » Mon Jun 27, 2016 12:04 am

So it does, if its only there why not simply connect it up lol

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