I'm trying to use Grove LED Bar with Arduino

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Grove – LED Bar is comprised of a 10 segment LED gauge bar and an MY9221 LED controlling chip. It can be used as an indicator for remaining battery life, voltage, water level, music volume or other values that require a gradient display. There are 10 LED bars in the LED bar graph: one red, one yellow, one light green, and seven green bars. Demo code is available to get you up and running quickly. It lights up the LEDs sequentially from red to green, so the entire bar graph is lit up in the end.

In the github example there are Clock pin, Data pin and Orientation.

// Arduino Clock pin, Data pin, Orientation 
// Grove_LED_Bar bar(7, 6, 0);  


But I have no idea what are they. Where can I find the documentation for them?

  • Did you try Google it? It take only a few minutes ... – user31481 Oct 27 '17 at 11:46
  • It took me over an hour and with your answer I still can't get it. I asked what is "Clock pin". And your answer doesn't have the word. Probably it's because of lack of my basic knowledge, though. – ironsand Oct 28 '17 at 0:59
  • Grove modules are like Lego for electronics. You can connect your Grove module directly to Arduino, as Ratchet suggest, and it will works.. What the Grove shield gives to you is error-free, secure and clean connections instead of a rat nest breadboard. – user31481 Oct 28 '17 at 10:04

on the LED circuit board there are a few connections, notably DI and DCKI.

The DI pin is the data pint and DCKI is the clock pin.

According to the header orientation is about which way the pins are oriented red-to-green or green-to-red. It affects at which end led 1 is.

  • Thanks I get it now! So I had to guess that DCKI represents clock pin, right? Or maybe there is a rule for abbreviation? – ironsand Oct 28 '17 at 1:05

How to connect Grove to your board

You need a Grove Expansion Board which to attach the Grove modules. The Grove Expansion Board provides the processing power, and the modules offer the input sensors and output actuators of your system. There are many Grove Expansion Board for different platform already, they include Arduino UNO, Particle Phone, BeagleBone board etc.

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There are intotal 16 grove connectors on the Base Shield, here we use a table to show the details.


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Apart from the rich grove connectors, on the board you can also see an RST button, a green LED to indicating power status, ICSP pin, a toggle switch and four row of pinouts. There is no need to explain the RST button and LED, but you really need to know below two features that is very important for your usage.

1.Power Compatible:

Every Grove connector has four wires, one of which is the VCC. However, not every micro-controller main board needs a supply voltage of 5V, some need 3.3V. That's why we add a power toggle switch to Base Shield v2 so that you can select the suitable voltage of the micro-controller main board you are using via this switch.

For example, if you are using Arduino UNO with Base Shield v2, please turn the switch to 5v position; while using Seeeduino Arch with Base Shield v2, please turn the switch to 3.3v.

2.Board Compatible:

The pinout of Base Shield V2 is the same as Arduino Uno R3, however Arduino Uno is not the board one that the Base Shield V2 is compatible with, here we listed the boards that we have confirmed that can be used with Base Shield V2.

Arduino Uno

Seeeduino V4.2

Arduino Mega / Seeeduino Mega

Seeduino LoraWan

Arduino Leonardo / Seeeduino Lite

Arduino 101

Arduino Due

Intel Edison

Linkit One

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