RDIoT Demo

SunFounder RAB 5 in 1 Breadboard [B193]

* Specs

1) Compatibale with Raspberry Pi 3 Model B,2 Model B and 1 Model B+. 

2) For any Arduino board whose mounting holes are the same with For Arduino UNO and Mega 2560 can be fixed upon this Holder with screws. 

3) Be able to fix the 400 points and 800 points self-adhesive breadboard.

4) There are M3 fixing holes in the middle which can be used to fix the RAB Holder upon your experiment table.

5) Size:200*135mm ->7.87inch * 5.31inch.

- Technical Details Introduction

RAB Holder, also called Raspberry Pi, For Arduino and Breadboard Holder. Presumably you can know its function from the name. It can ensure the security of your demoboard and avoid placing the demoboard on the desk freely to cause short cut. The RAB Holder also simplifies your experiment when you are building a complex circuit. There are three zones on the RAB Holder and each has a name on it. We have made some slots in the zone that used to fix the Raspberry Pi to make the use more comfortable.

A screwdriver is provided for you to install the Raspberry Pi and for Arduino board onto the holder with screws. 

- Package Contents

2x M3*10 Screw 

4x M2.5*6 Screw 

6x M3*6 Screw 

1x RAB Holder

1 x Screwdriver

Elecrow TFT HDMI Display 7 Inch 1024x600 [B190]

https://www.youtube.com/watch?v=sefEwRMQRoc

* Specs

Power: DC 7.5v-12v/1.5-2A

16:10 display ratio

Resolution:1024x600

Visible area: 150mm x 85mm

Weight:300

* Contents

- Yes, this is an adorable small HDMI television with incredibly high resolution! We tried to get the smallest possible HDMI display with high-res, high-contrast visibility. The display is very easy to use 

- it should be powered by 12DC, then connect a digital video source to one of the ports. It work connect to any device with direct HDMI such as raspberry pi, banana pi and pcduino. The biggest difference is that it can work when you plug it on device without any software support.

- If you want a power adapter : 12V/2A Power Supply

Raspberry Pi Apache Kafka Cluster [P013]

https://www.youtube.com/watch?v=dAVwsc1Zhfo

* Parts

- Raspberry Pi 3 B Model (RASPBERRY-PI-3-B) [B088] x 3ea

- USB Power Supply

- Ethernet Hub

* Contents

- Installation & Setup

1. JDK

$ sudo apt-get install openjdk-8-jdk 

2. Kafka

$ cd 

$ mkdir kafka

$ wget http://apache.tt.co.kr/kafka/0.10.1.0/kafka_2.11-0.10.1.0.tgz

$ tar zxvf kafka_2.11-0.10.1.0.tgz

3. hosts

$ vi /etc/hosts

192.168.0.11 kafka-pi-01 

192.168.0.12 kafka-pi-02 

192.168.0.13 kafka-pi-03 

4. Config Zookeeper 

$ vi config/zookeeper.properties (added)

initLimit=5 

syncLimit=2 

server.1=kafka-pi-01:2888:3888 

server.2=kafka-pi-02:2888:3888 

server.3=kafka-pi-03:2888:3888

$ mkdir /tmp/zookeeper (each server)

$ echo 1 > /tmp/zookeeper/myid 

$ echo 2 > /tmp/zookeeper/myid 

$ echo 3 > /tmp/zookeeper/myid 

5. Config Kafka

$ vi config/server.properties (each server 1,2,3)

broker.id=1 

zookeeper.connect=kafka-pi-01:2181,kafka-pi-02:2181,kafka-pi-03:2181

* Demo Test Script

1. Zookeeper Cluster Start

/home/dragon/kafka/kafka/bin/zookeeper-server-start.sh -daemon /home/dragon/kafka/kafka/config/zookeeper.properties

2. Kafka Cluster Start

/home/dragon/kafka/kafka/bin/kafka-server-start.sh -daemon /home/dragon/kafka/kafka/config/server.properties

3. Create topics

/home/dragon/kafka/kafka/bin/kafka-topics.sh --create --zookeeper kafka-pi-01:2181 --replication-factor 3 --partitions 5 -topic rdtest

4. Producer 

/home/dragon/kafka/kafka/bin/kafka-console-producer.sh --broker-list kafka-pi-01:9092 --topic rdtest

5. Consumer

/home/dragon/kafka/kafka/bin/kafka-console-consumer.sh --zookeeper kafka-pi-01:2181 --topic rdtest --from-beginning

6. Start KafkaOffsetMonitor

java -cp KafkaOffsetMonitor-assembly-0.2.1.jar \

com.quantifind.kafka.offsetapp.OffsetGetterWeb \

--zk kafka-pi-01:2181,kafka-pi-02:2181,kafka-pi-03:2181 \

--port 8080 \

--refresh 10.seconds \

--retain 2.days &

7. Monitor Kafka 

http://192.168.0.11:8080

8. How to solve the "map failed" problem in the 32bit raspberry pi.

- edit kafka-run-class.sh 

- replace the KAFKA_JVM_PERFORMANCE_OPTS as follows

# JVM performance options

if [ -z "$KAFKA_JVM_PERFORMANCE_OPTS" ]; then

  #KAFKA_JVM_PERFORMANCE_OPTS="-server -XX:+UseParNewGC -XX:+UseConcMarkSweepGC -XX:+CMSClassUnloadingEnabled -XX:+CMSScavengeBeforeRemark -XX:+DisableExplicitGC -Djava.awt.headless=true"

  KAFKA_JVM_PERFORMANCE_OPTS="-server -XX:+UseG1GC -XX:MaxGCPauseMillis=20 -XX:InitiatingHeapOccupancyPercent=35 -XX:+DisableExplicitGC -Djava.awt.headless=true"

fi

- add KAFKA_HEAP_OPTS under 1G

export KAFKA_HEAP_OPTS="-Xmx256M -Xms128M"