Difference between revisions of "Lickometer"
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(add links to adafruit tutorial and software) |
(added enable i2c) |
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[https://github.com/adafruit/Adafruit_Python_MPR121 Adafruit Python library] | [https://github.com/adafruit/Adafruit_Python_MPR121 Adafruit Python library] | ||
| − | ===Patch for | + | ===Enable I2C=== |
| + | |||
| + | Be sure to enable i2c! | ||
| + | |||
| + | raspberry menu -> Preferences -> Raspberry Pi Configuration -> Interfaces => enable I2C | ||
| + | |||
| + | see [https://learn.adafruit.com/adafruits-raspberry-pi-lesson-4-gpio-setup/configuring-i2c Configuring I2C] | ||
| + | |||
| + | ===Patch for I2C=== | ||
"the latest Raspbian Jessie and Stretch releases have an updated I2C driver that isn't compatible with how this library enables repeated I2C start bits. | "the latest Raspbian Jessie and Stretch releases have an updated I2C driver that isn't compatible with how this library enables repeated I2C start bits. | ||
| Line 38: | Line 46: | ||
sudo apt-get update | sudo apt-get update | ||
sudo apt-get install build-essential python-dev python-smbus python-pip git | sudo apt-get install build-essential python-dev python-smbus python-pip git | ||
| + | |||
| + | ===Install Python MPR121 Library=== | ||
| + | |||
| + | cd ~ | ||
| + | git clone https://github.com/adafruit/Adafruit_Python_MPR121.git | ||
| + | |||
| + | ===Run Test Software=== | ||
| + | |||
| + | cd Adafruit_Python_MPR121 | ||
| + | sudo python setup.py install | ||
Revision as of 20:38, 31 July 2018
Raspberry PI Lickometer
Touch Sensor
Datasheet for MPR121: https://cdn-shop.adafruit.com/datasheets/MPR121.pdf
Materials
Total: $124.80 (not including shipping, about $30)
| -Item PID Price Quantity Total |
|---|
| Raspberry Pi 3 Model B Starter Pack - Includes a Raspberry Pi 3 3058 $84.95 1 $84.95 |
| Adafruit Capacitive Touch HAT for Raspberry Pi - Mini Kit - MPR121 2340 $14.95 1 $14.95 |
| Adafruit Perma-Proto Half-sized Breadboard PCB - Single 1609 $4.50 1 $4.50 |
| Small Alligator Clip Test Lead (set of 12) 1008 $3.95 1 $3.95 |
| Adafruit Capacitive Touch HAT for Raspberry Pi - Mini Kit - MPR121 2340 $14.95 1 $14.95 |
| Brass M2.5 Standoffs for Pi HATs - Black Plated - Pack of 2 2336 $0.75 2 $1.50 |
Software
Enable I2C
Be sure to enable i2c!
raspberry menu -> Preferences -> Raspberry Pi Configuration -> Interfaces => enable I2C
see Configuring I2C
Patch for I2C
"the latest Raspbian Jessie and Stretch releases have an updated I2C driver that isn't compatible with how this library enables repeated I2C start bits. From the thread about this issue there's a workaround to enable the older I2C driver. Edit the /boot/config.txt on your SD card and add:
dtoverlay=i2c-bcm2708
Dependencies
sudo apt-get update sudo apt-get install build-essential python-dev python-smbus python-pip git
Install Python MPR121 Library
cd ~ git clone https://github.com/adafruit/Adafruit_Python_MPR121.git
Run Test Software
cd Adafruit_Python_MPR121 sudo python setup.py install