Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

Awesome Lists | Featured Topics | Projects

https://github.com/suryasundarraj/rpi-mcp3008-analogData-thingspeak

This Project has a basic demo with analog sensor, where the data from the analog sensor are visualized in the thingspeak api
https://github.com/suryasundarraj/rpi-mcp3008-analogData-thingspeak

Last synced: 3 months ago
JSON representation

This Project has a basic demo with analog sensor, where the data from the analog sensor are visualized in the thingspeak api

Awesome Lists containing this project

README 

        
# Sensing Analog Signal using Raspberry Pi



Basic Setup to integrate analog sensor with Raspberry Pi, where the data from the analog sensor are visualized in the Thingspeak API. This repository accompanying  with this [blog post](http://radiostud.io/sensing-analog-signal-raspberrypi/).



# OVERVIEW



This Project Demonstrates how to integrate the analog input with the raspberry pi and track the data. The data is also visiualized with the Thingspeak API. There is no inbuilt analog input for the raspberry pi, MCP3008 is Analaog to Digital Converter which is used to interface the analog sensor with the Raspberry Pi. 



The interface between the MCP3008 and Raspberry Pi is acheived using SPI Communication Protocol.



# PREREQUISITES 



1.  Raspberry Pi with Raspbian OS 



2.  Account on Thingspeak and generate a channel, you will be provided with the unique API Key 



# Thingspeak Configuration



Step 1: Login to your Thingspeak Account 



Step 2: Click on Channels -> My Channels 

[image_channel]: images/channel.png

![image] [image_channel]



Step 3: Open the channel created by you and Click on API Keys

[image_apikey]: images/apikey.PNG

![image] [image_apikey]



Step 4: Copy the Write API Key and Paste it on the adcRpi/adcRpi.py Line Number 11



# Build and Install 



## Setting up the SPI enviroinment on Raspberry Pi



This process assumes you are using the latest Raspbian build from the official downloads page. You can update your current image using :



    sudo apt-get update

    sudo apt-get upgrade



To enable hardware SPI on the Pi we need to make a modification to a system file :



    sudo nano /boot/config.txt



Add the following line at the bottom :



    dtparam=spi=on

  

Use CTRL-X, then Y, then RETURN to save the file and exit. Reboot using the following :



    sudo reboot



## Checking If SPI Is Enabled (Optional)



To check if the SPI module is loaded by the system run the following command :



    lsmod



You should see “spi_bcm2708″ or “spi_bcm2835” listed in the output. You can use the following command to filter the list and make it easier to spot the spi entry :



    lsmod | grep spi_



SPI is now enabled.



## Python SPI Wrapper



In order to read data from the SPI bus in Python we need a library. This library is included in the latest Raspbian image so if you’ve got an uptodate SD card you don’t need to do anything else. You can confirm you’ve got “python-spidev” and “python3-spidev” installed by using :



    apt-mark showauto | grep spi



You should see the two python spidev packages listed in the output.



## Installation Step



Previously you needed to install a library called ‘py-spidev’. I’ve left the instructions here for anyone who is using an older image.



To install it we first need to install ‘python-dev’ :



    sudo apt-get install python2.7-dev



Then to finish we can download ‘py-spidev’ and compile it ready for use :



    wget https://github.com/Gadgetoid/py-spidev/archive/master.zip

  

    unzip master.zip

  

    rm master.zip

  

    cd py-spidev-master

  

    sudo python setup.py install

  

    cd ..



## LOOPBACK TEST



This can be used to test SPI send and receive. Put a wire between MOSI and MISO. It does not test CE0 and CE1.



wget https://raw.githubusercontent.com/raspberrypi/linux/rpi-3.10.y/Documentation/spi/spidev_test.c



gcc -o spidev_test spidev_test.c



./spidev_test -D /dev/spidev0.0



### OUTPUT:



spi mode: 0

bits per word: 8

max speed: 500000 Hz (500 KHz)



FF FF FF FF FF FF

40 00 00 00 00 95

FF FF FF FF FF FF

FF FF FF FF FF FF

FF FF FF FF FF FF

DE AD BE EF BA AD

F0 0D