Here we are again - trying to continue the tradition of updating my Power BI analysis of the Dutch Radio 2's Top 2000.
This year however, the report was fully redesigned by my friend Marc Lelijveld after he complained it was really outdated. He was right, of course. So I (t)asked him to update it.
Here is the result. I must say, it looks really cool! Thanks Marc, great job!
Ok, trying something new here - as you might know, I have been having fun with home automation for a while now. Home Assistant is my platform of choice. I will start writing down the more interesting things I did to make my house "smarter" and publish them on this blog. This is the first of many (?) - we will see how it goes.
The problem
One thing we never seem to get right is when to water plants. We either overfeed them or forget them. In either case, they die quickly.
As part of my many home automation endeavors I wanted to build an automatic plant watering system.
The basic idea was: a water pump in a glass of water, a moisture sensor and whenever the soil the moisture sensor is measuring is dry, the water pump provides water until the soil is wet.
I say almost, because when you assemble this kit it does the opposite from what you need. Basically, when the sensor reports the soil is wet, the motor turns on and when the soil is dry, the motor turns off. Update: after posting this I figured out you could also solve this issue by connecting to the NC instead of the NO of the relay.
Also, it is not very clear how you need to connect this kit to make it work.
See the original kit in action below:
Putting it together
Here is what I did:
First, I used the USB cable that came with the kit to provide power (you can use another way of getting 5V of power)
Then, I added a 2N700 transistor to build a simple inverter (see http://www.learningaboutelectronics.com/Articles/Transistor-inverter-circuit.php). It takes the input from the moisture sensor and provides it to the relay, effectively reversing the effect: when the soil is dry, turn on the pump, when the soil is wet, turn off the pump. You can use the small potentiometer on the moisture sensor breakout board to adjust sensitivity to moisture. You need a 1M Ohm resistor as well.
This is the circuit on a breadboard:
These are the connections:
Moisture sensor: connect to two pin side of breakout board. Does not matter which way.
Moisture sensor breakout board:
VCC --> +5V
GND --> GND
D0 (digital output) --> input of 2N700 (middle)
2N700 inverter:
Left --> GND
Middle --> D0 (digital output) of moisture sensor breakout board
Right --> 1M resistor --> +5V and to Input of relay
Relay:
VCC --> +5V
GND --> GND
IN --> Right output of 2N700
COM --> +5V
NO --> Red wire of water pump
Water pump:
Black --> GND
Red --> NO of Relay.
This is the final setup (before making it look pretty with a case and longer wires):
This one is easy once you know how to do it. It is also buried in the documentation.Kasper de Jonge mentioned it to me on Twitter and I thought it would not hurt to just write it down quickly (also to make it easier for myself to find it in the future):
Default behavior of Power BI is to show (Blank) when there is nothing, even when summing a numerical column that happens to be all empty. But what if you want to show 0 instead? Well, with COALESCE you can.
In this simple example I have a table showing sales per region for a company that is not doing so good - they are not selling anything.
Sales are null, maybe it's the Regions?
Assuming SalesAmount is a numerical column, if you make a visual with this you get:
Technically correct return value
Business users might just want to see 0 in this case, not the (more correct) (Blank). To make this happen, add a simple measure:
The way this works is that the COALESCE function will just return the first thing it finds reading from left to write in the parameter list that is not null/blank. That happens to be 0. If for whatever reason you wanted to show -1 when there are no sales, you can do that as well, just change the 0 to -1.
Enjoy and don't forget to feel good about making your business users happy :)
I do not claim that what is included in this post is the perfect way of doing things. However, some things related to Azure SQL firewall settings for Power BI data refresh caught me by surprise recently so I figured I would just write it down...
The scenario
You have built a Power BI dashboard that takes data from Azure SQL and want to have this report automatically refreshed in the Power BI Service.
Data refresh scenarios in Power BI
There are two ways of refreshing data in Power BI: the classic Power BI refresh and the refresh using a Dataflow. I will discuss the options separately because they have separate impact on the firewall settings on your Azure SQL database.
'Classic' Power BI Refresh
What I mean with 'classic' Power BI Refresh is the refresh that you can configure without using a Dataflow. You will find it on your dataset settings:
Now for this to work you will need to enter the credentials and allow Power BI to reach the Azure SQL database through the firewall. This is where the fun starts. If you have a new Azure SQL database you will not have touched the firewall at all or allowed your office IP through to be able to access it from Power BI Desktop and build a report.
If you enter your credentials on the Dataset settings page in Power BI and try to refresh, you will get an error because Power BI is not allowed through the firewall. In order to allow this there are a couple of options:
Allow Azure services and resources access to the Azure SQL Server. You will find this button in the Azure Portal on the Azure SQL Server firewall configuration. Set it to 'Yes' and your refresh works. This is what is recommended in the official documentation. Sometimes, however, this is not an option since it opens the Azure SQL Database for more than just Power BI - it would allow any Azure Service to communicate to the database after authentication. For example, Azure Data Factory could now be used against this Azure SQL Database. This might be just what you want, or not, it depends on the security rules in your organization. It is the easiest and my preferred solution.
Alternatively, you could use VNets and the Power BI Gateway (in a VM) to pull this off without opening up the firewall to all Azure Services, as it explained here and here. This is more restrictive but has the downside of a more complex and less cost-effective solution since you have to set up a VNet and a Power BI Gateway in a VM.
Lastly you could figure out the IP addresses used by Power BI and allow those to go through the firewall. Downside is that those IP addresses can change without notice and you would have go in and manually make changes for the refresh to work. I would not recommend doing it, but if you want to try here is a script.
Dataflows
If you use Dataflows you can still use the options described above. However, there is a third and more hacky way of doing things: a script or Azure Automation Runbook.
Azure publishes the IP address ranges used for some Azure Services here. Unfortunately, Power BI 'classic' refresh uses IP ranges that are not documented here. Note that it is published per cloud - so if you are not in the public cloud you will need to download a different file. With this file you can do a manual update of the firewall (similar to #3 above) or try to do it automatically like I did below. If the IPs change you can use this file to retrieve the changes and make updates accordingly.
For the automatic solution you could write a script or use Azure Automation. I wrote a very hacky script which downloads the file mentioned above for public cloud, parses it and adds the rules for Data Flows to the Azure SQL firewall. Again, it is very hacky, but it works. You can either run this script manually, schedule it or plug this in Azure Automation to run it automatically. You can get the script here or read it below. Remember to use this at your own risk. I am not responsible for you not being able to access your Azure SQL database anymore because of this script.
#DutchDataDude.com
#Code is provided as is.
Install-Module Az.Network -Scope CurrentUser
#CONFIG
$resourcegroup = "[ResourceGroupForAzureSQLDatabase]"
$server= "[AzureSQLServerName]"
$subscriptionId = "[SubscriptionID]"
$location = "[LocationForResourceGroupAndAzureSQLServer]"
#this is the URL for public clouds, for other clouds use appropriate URL
$url = "https://download.microsoft.com/download/7/1/D/71D86715-5596-4529-9B13-DA13A5DE5B63/ServiceTags_Public_20200420.json"
#source: https://gallery.technet.microsoft.com/scriptcenter/Start-and-End-IP-addresses-bcccc3a9
function Get-IPrangeStartEnd
{
<#
.SYNOPSIS
Get the IP addresses in a range
.EXAMPLE
Get-IPrangeStartEnd -start 192.168.8.2 -end 192.168.8.20
.EXAMPLE
Get-IPrangeStartEnd -ip 192.168.8.2 -mask 255.255.255.0
.EXAMPLE
Get-IPrangeStartEnd -ip 192.168.8.3 -cidr 24
#>
param (
[string]$start,
[string]$end,
[string]$ip,
[string]$mask,
[int]$cidr
)
function IP-toINT64 () {
param ($ip)
$octets = $ip.split(".")
return [int64]([int64]$octets[0]*16777216 +[int64]$octets[1]*65536 +[int64]$octets[2]*256 +[int64]$octets[3])
}
function INT64-toIP() {
param ([int64]$int)
return (([math]::truncate($int/16777216)).tostring()+"."+([math]::truncate(($int%16777216)/65536)).tostring()+"."+([math]::truncate(($int%65536)/256)).tostring()+"."+([math]::truncate($int%256)).tostring() )
}
if ($ip) {$ipaddr = [Net.IPAddress]::Parse($ip)}
if ($cidr) {$maskaddr = [Net.IPAddress]::Parse((INT64-toIP -int ([convert]::ToInt64(("1"*$cidr+"0"*(32-$cidr)),2)))) }
if ($mask) {$maskaddr = [Net.IPAddress]::Parse($mask)}
if ($ip) {$networkaddr = new-object net.ipaddress ($maskaddr.address -band $ipaddr.address)}
if ($ip) {$broadcastaddr = new-object net.ipaddress (([system.net.ipaddress]::parse("255.255.255.255").address -bxor $maskaddr.address -bor $networkaddr.address))}
if ($ip) {
$startaddr = IP-toINT64 -ip $networkaddr.ipaddresstostring
$endaddr = IP-toINT64 -ip $broadcastaddr.ipaddresstostring
} else {
$startaddr = IP-toINT64 -ip $start
$endaddr = IP-toINT64 -ip $end
}
$temp=""|Select start,end
$temp.start=INT64-toIP -int $startaddr
$temp.end=INT64-toIP -int $endaddr
return $temp
}
# Sign-in with Azure account credentials
Connect-AzAccount
$context = Set-AzContext -SubscriptionId $subscriptionId
$output = "$PSScriptRoot\servicetags.json"
#download the service tags and convert to Json
Invoke-WebRequest -Uri $url -OutFile $output
$j = Get-Content $output | ConvertFrom-Json
#remove all firewall rules for PowerQueryOnline
$existingrules = Get-AzSqlServerFirewallRule -ResourceGroupName $resourcegroup -ServerName $server
foreach ($rule in $existingrules) {
if ($rule.FirewallRuleName -match "PowerQuery") {
write-host "Removing rule " $rule.FirewallRuleName
Remove-AzSqlServerFirewallRule -ResourceGroupName $resourcegroup -ServerName $server -FirewallRuleName $rule.FirewallRuleName -DefaultProfile $context
}
}
$v = $j.values
foreach ($val in $v) {
if ($val.name -match "PowerQuery") {
$addresses = $val.properties.addressPrefixes;
foreach($address in $addresses) {
$split = $address.Split('/')
$startend = Get-IPRangeStartEnd -ip $split[0] -cidr $split[1]
$end = $startend.end
$start = $startend.start
$rulename = $val.name+":"+$start+"-"+$end
#add rules
write-Host "Adding " $rulename
New-AzSqlServerFirewallRule -ResourceGroupName $resourcegroup -ServerName $server -FirewallRuleName $rulename -StartIpAddress $start -EndIpAddress $end -DefaultProfile $context
}
}
}
I hope this helps. Let me know if I missed anything!
I am writing this post not to claim that I know everything there is to know about Azure Networking. Not even remotely. I am writing this partly for myself and hopefully to help others. Today I hit the following error while trying to write a PowerShell script to automate some Azure Networking related tasks (more on that soon!): 'Subscription [subscriptionID] is not registered with NRP'. In this short post I will explain how to fix this error.
I searched online but could not find the solution anywhere. Then it hit me - NRP = Network(ing?) Resource Provider. The solution is straightforward:
Make a note of the subscriptionID from the error message.
In the Azure Portal go to Subscriptions and find the offending subscription.
Click on Resource Providers.
Search for 'Microsoft.Network'.
You will see that the status for that provider is 'NotRegistered'. Select 'Microsoft.Network' and click 'Register'. Wait for it to say 'Registered' (if you are as inpatient as I am you can click 'Refresh' to get the latest status).
Note that you do not need to register for 'Microsoft.ClassicNetwork'.
Done, now execute your script again and the error should disappear!
Dutch Data Dude
