In the event of a power outage, an analogue power socket timer switch will simply turn off. When then power returns, the unit is not aware of how long the power has been out for and the timer will continue from when the power cut.
If a digital timer is used, on power being restored, the time should be correct with your on/off schedule preserved.
When using a Linux system (Raspberry Pi) and Cron to set a scheduled task, if a power cut occurred within the time an action was supposed to initiate, this window will be missed as when the system power is restored the action event would have passed and won’t be initiated until the next scheduled time.
For the ARPIC or Linux system to act like a 7 day digital timer a script is used on start up to check the time.
Continue reading ARPIC – Time Check Boot Script
Whilst setting up a new APRIC I noticed that the time was not updating as expected, no update on boot.
I have not setup an RTC on this unit yet, but NTPD would need to be installed anyway to updated the RTC later.
It appears in the Jan 2018 release of Rasbian Lite Stretch does not have NTPD installed as default.
A quick way to check the time and date configuration is to use timedatect1
Continue reading ARPIC – Raspbian Light Stretch NTP
ARPIC – Another Raspberry Pi Controller
4GB or larger Micro SD card
Network connection – cable or WiFi
PC with an SD card reader (Windows OS in this example)
For help getting Raspbian onto your SD card, take a look at these pages;
Lets get started!
- Connect the Raspberry Pi to your network, you can either plug up a keyboard and monitor or SSH into the Pi using Putty.
- Login to the Pi using the default credentials ( pi \ raspberry ).
- Its always best to run a system update even on a new install;
sudo apt-get update && sudo apt-get dist-upgrade
- Once the system update has completed, restart and log back in.
- Type the below code to access the raspi-config file;
For this project, the changes to the raspi-config file are listed below, refer to official, easy to use documentation from RaspberyPi.org if you get stuck.
7 Advanced Options, Select
A1 Expand Filesystem
5 Interface Options, Select
P2 SSH and Enable
5 Interface Options, Select
P7 1-Wire and Enable
4 Localisation Options, Select
I2 Change Timezone & location and set
2 Network Options, Select N1 Hostname and set your desired hostname
2 Network Options, If your using a compatible WiFi dongle, the SSID and passpharase can be entered under option N2
Once completed, Select the
Finish option and select
Yes at the prompt to restart.
After following guides to install my preferred web server for the Raspberry Pi, Lighttpd, I always seem to have a problem with permissions when modifying files in or under /var/www/ folder.
In the guides that have I have gone through you do go through adding the Pi user to the www-data folder and what not but you will still get Permission Denied error when trying to add/remove/modify/create files when SFTP’ing in.
Continue reading Raspberry Pi FTP WWW Folder Permission issues
How to read a temperature probe, save the value to a MySQL database and then show the value on a webpage or just show the value with no database.
See this link for how to setup a DS18B20+ thermal probe with a Raspberry Pi, these instructions are the best that i have come across for this and will cover the bullet points below :
- Enabling the 1 wire features in the Raspbian OS
- Physically connecting the probe via a resistor to the RPi
- Instructions on how to read the probe and a script example
Once you have followed the above steps you should have a working temperature probe, that’s great.. but what can you do with it now!?
Continue reading Raspberry Pi Thermal Probe