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Raspberry Pi remote sensors

Posted on May 1, 2013 3:09 pm by Johan

I recently bought a Raspberry Pi to experiment with. The first things I did with it was connecting and reading out Maxim Integrated DS1820 one wire temperature sensor and the cheap Chinese DHT11 temperature / relative humidity sensor.

To connect the sensors, I soldered some female pin headers to a piece of PCB. For the one wire network I soldered a 4.7K resistor between Vcc on pin1 (3.3V) and GPIO4 on pin 7. GPIO4 is the data pin for one wire, I used GPIO2 as the data pin for the DHT11. DHT11 “modules” with a PCB and three pins have their own pull up resistor, the separate 4 pin sensors don’t. Shown below is the quick setup, I soldered the DS1820 directly to the PCB, and connected the DHT11 with some wires for 3.3V, data and ground.

GPIO pinouts differ between the Raspberry Pi versions, I found the following pinout to be correct for my Raspberry Pi, a model A version 2.

Reading out the sensors is easy. For the DS1820, load the required kernel modules which are included in the Raspbian Linux distribution: Continue reading → Post ID 1179

📂This entry was posted in computers-networking Electronica english wetenschap/science 📎and tagged cacti dht11 ds1820 Electronica linux raspberry pi raspbian sensors snmp
Arduino/Cacti Geiger counter update

Posted on September 6, 2011 8:22 pm by Johan

My online geiger counter which I described earlier has been offline for some time. During that time I experimented with a standalone Arduino with the goal of making a dedicated board for the setup. I have now completed the board shown in the picture below.

In the picture you can see the HV generator on the top of the board, on the lower left the Arduino standalone parts along with a MAX232 as a level converter for easy serial hookup and on the right two tubes connected in parallel, a SI-29BG (beta and gamma) and a SI-12B for added alpha sensivity. Also shown are the USB>Serial adapter and a separate USB connector to provide 5V to the board. Continue reading → Post ID 1179

📂This entry was posted in computers-networking english wetenschap/science 📎and tagged arduino cacti english geiger counter radioactiviteit radioactivity
Online geiger counter using Arduino and Cacti

Posted on April 2, 2011 6:21 pm by Johan

I have always had an above average interest in radioactivity. It’s a subject with political, sociological and scientific aspects. I have been mostly interested in the scientific part, but I also closely follow any news and other developments. With the earthquake in Japan and the following nuclear disaster the discussion about nuclear energy has been fired up after being quite silent for years. In the Netherlands there was talk about building a new reactor next to the existing plant in Borssele. Well, I guess it will be a bit harder now to get support for this plan…

To be honest, watching the developments with the damaged reactors in Japan got me thinking again. Is nuclear energy a proper way of generating electricity? Sure, for the immediate surroundings it is very clean. There are virtually no CO2 emissions and with proper shielding and maintenance you’ll need some pretty advanced equipment to measure any radioactivity coming from a reactor. Still, uranium mining is not very nice for the environment and there is no clear solution for storage of waste. And, if a reactor malfunctions there is the possibility of widespread contamination as currently seen in Japan. So, while I am not against nuclear energy my support for it has weakened somewhat.

Anyway, enough rambling, how to monitor radiation with your computer!

Update 18/4: Guess I am not the only one doing some monitoring: http://radgoes.blogspot.com

Continue reading → Post ID 1179

📂This entry was posted in Electronica english wetenschap/science 📎and tagged arduino cacti Electronica geigercounter radioactiviteit radioactivity solderen
DS1820 Temp. monitoring using Linux and Cacti

Posted on October 4, 2010 3:23 pm by Johan

This article will try to explain how to monitor and graph temperatures remotely using Dallas Semiconductor DS18xx sensors, SNMP and Cacti. DS18xx sensors are relatively cheap, accurate and multiple sensors can be connected to a single bus.

This guide is based on Ubuntu, so YMMV on other Linux/Unix based systems and may need modification to work properly.

Continue reading → Post ID 1179

📂This entry was posted in computers-networking Electronica english wetenschap/science 📎and tagged cacti ds1820 sensor temperature

Raspberry Pi remote sensors

Arduino/Cacti Geiger counter update

Online geiger counter using Arduino and Cacti

DS1820 Temp. monitoring using Linux and Cacti