{"id":14077,"date":"2016-03-10T10:56:13","date_gmt":"2016-03-10T02:56:13","guid":{"rendered":"http:\/\/www.seeedstudio.com\/blog\/?p=14077"},"modified":"2018-10-19T10:21:18","modified_gmt":"2018-10-19T02:21:18","slug":"tutorial-grove-connector-project-examples-for-raspberry-pi-arduino","status":"publish","type":"post","link":"https:\/\/www.seeedstudio.com\/blog\/2016\/03\/10\/tutorial-grove-connector-project-examples-for-raspberry-pi-arduino\/","title":{"rendered":"Tutorial: Grove Connector Project Examples for Raspberry Pi \/ Arduino"},"content":{"rendered":"

At SwitchDoc Labs, we have been building prototypes for engineering projects for many years. Sometimes they move to being a product, sometimes not. We have been on the lookout for a good pluggable prototyping system that allows swap outs of parts and yet has a good mechanical interface. We have looked at a variety of systems over the years. What did we want? We wanted something that is supported by a number of manufacturers, no licensing fees involved, easy for beginners and younger folks to use, straight forward enough so we can build boards without much problem and flexible enough for use with all three of the Raspberry Pi, Arduino and the ESP8266. We have now found such a system that has some significant support in the industry.<\/p>\n

\"Figure-1-1\"<\/p>\n

All of the parts in this tutorial are available from www.seeedstudio.com<\/a> or www.robotmesh.com<\/a>.<\/p>\n

This is Part 2 of this series. Part 1 describes the whole Grove connector system<\/a>.<\/p>\n

Part 3 will describe a more complex Grove application using the new Dual Grove\/Pin Headers I2C 4 Channel Mux.<\/a><\/p>\n

What is the Grove System?<\/h3>\n

\"FullSizeRender-10-1\"<\/p>\n

Grove<\/a> is a modular, standardized connecter prototyping system. Grove takes a building block approach to assembling electronics. Compared to the jumper or solder based system, it is easier to connect, experiment and build and simplifies the learning system, but not to the point where it becomes dumbed down. Some of the other prototype systems out there takes the level down to building blocks. Good stuff to be learned that way, but the Grove system allows you to build real systems. It requires some learning and expertise to hook things up.<\/p>\n

The Grove system consists of a base unit and various modules with standardized connectors.<\/p>\n

The Base unit, generally a microprocessor, allows for easy connection of any input or output from the Grove modules. and every Grove module typically addresses a single function, such as a simple button or a more complex heart rate sensor.<\/p>\n

You don\u2019t need a Base unit to connect up to Grove modules. You an use a cable (Grove to Pin Header Converter) to run from the pins on the Raspberry Pi or Arduino to the Grove connectors. That is what We do in the SunRover project and in the examples below.<\/p>\n

So what is a Grove Connector?<\/h3>\n

\"Figure-2\"<\/p>\n

Figure 2A Grove connector is a four pin standardized size connector used to plug into base units and Grove modules. Figure 1 shows the male Grove Connector. The male connectors come in flat 90 degree versions and vertical versions as in Figure 2. Seeedstudio has the exact dimensions in this specification [ http:\/\/www.seeedstudio.com<\/a>\/wiki\/images\/6\/69\/3470130P1.pdf<\/a>]. These standardized connectors (common to all types of Grove Connectors) are the key to making this system work. They are keyed to prevent plugging them in backwards, and the four types of connectors (see below) are all designed so that if you plug the wrong type of device into the wrong type of base unit, there is no problem. They just won\u2019t work. This is a good thing.<\/p>\n

The one exception would be if you plugged in a 3.3V I2C Grove module that is non-5V tolerant into a 5V I2C Grove connector you could fry the device.<\/p>\n

In this post we discuss four simple grove projects.<\/p>\n

Project 1: Connection a Grove Fan to the Raspberry Pi<\/h3>\n

We chose three simple, yet visually interesting Grove projects. The first module is the Grove Fan module. It is a Digital Grove module. The wiring was simple. I connected GPIO17 to D0 and 5V and GNDFigure 6 using a jumper to Grove To Pin Header Converter connector cable (always have these handy!). The software was very simple.<\/p>\n

\"Figure-6\"<\/p>\n

#
\n#
\n# Test the Grove Fan
\n#
\n# Digital Grove Connector
\n#
\n# Gnd, 5V, GPIO4, GPIO17
\n# Grove
\n# Gnd VCC D1 D0
\n#<\/p>\n

import time
\nimport RPi.GPIO as GPIO
\nGPIO.setwarnings(False)<\/p>\n

GPIO.setmode(GPIO.BCM)
\nGPIO.setup(17, GPIO.OUT)<\/p>\n

try:
\nwhile (1):<\/p>\n

GPIO.output(17, GPIO.HIGH)
\ntime.sleep(2.0)
\nGPIO.output(17, GPIO.LOW)
\ntime.sleep(2.0)
\nexcept KeyboardInterrupt:
\n# here you put any code you want to run before the program
\n# exits when you press CTRL+C
\nprint “keyboard Interrupt”<\/p>\n

except:<\/p>\n

print “other error”<\/p>\n

finally:
\nGPIO.cleanup() # this ensures a clean exit<\/p>\n

<a href=”http:\/\/www.switchdoc.com\/wp-content\/uploads\/2016\/02\/Figure-11.jpg” rel=”attachment wp-att-3352″><img class=”aligncenter size-large wp-image-3352″ src=”http:\/\/www.switchdoc.com\/wp-content\/uploads\/2016\/02\/Figure-11-1024×768.jpg” alt=”Figure 11″ width=”930″ height=”698″ \/><\/a><\/p>\n

 <\/p>\n

The only tricky part of this is that we use the Try \/ Except block to make sure that the GPIOs are tuned off (actually floating) when our program exits. Otherwise a bug in your code could leave the fan running.<\/p>\n

Of course, here is the video:<\/p>\n