It appears that there is a new Raspberry PI model available, the PiB+.
Here’s what we know so far.
- 4 USB 2.0 Ports (a change to the LAN9514, from the LAN9512
- Audio and Video Combined into a single A/V Jack similar to those found on camcorders
- External Active connectors have been moved to occupy only 2 sides of the board
- Increase in Mounting points to 4
- Move to a 40 Pin GPIO header
It looks like there may be some attempt to adopt the identification feature found on beablebone black capes, this note is present on the external connectivity schematic
ID_SD and ID_SC PINS:
These pins are reserved for ID EEPROM.
At boot time this I2C interface will be
interrogated to look for an EEPROM
that identifes the attached board and
allows automagic setup of the GPIOs
(and optionally, Linux drivers).
DO NOT USE these pins for anything other
than attaching an I2C ID EEPROM. Leave
unconnected if ID EEPROM not required.
Here’s some more images present elsewhere around the internet
Home automation typically starts with the measurement of temperature from many locations. Ideally this should be accomplished with a wireless sensor.
The arrival of Ciseco’s RFu-328 Arduino compatible wireless module it should hopefully be possible to make a more intelligent sensor platform, the aim a battery lifetime of > 1 year for a sample frequency of every minute.
- > 1 year battery life from 2xAA battery (2000mAH)
- Lightweight RF protocol
- OTA (Over the air) Firmware upgrades
- Low Cost base, Low power base station
- Modern Enclosure Design
- User definable sample frequency
- Over the air encryption
Using an RFU Developer Board , RFu-328 , and Slice of Radio for Raspberry PI all of which make use of Ciseco’s SRF RF Modules it has been possible to begin to explore the possibilities of creating an extensible sensor platform using off the shelf component parts.
Here it is.
Left to Right: 2xAA Battery pack, Ciseco RFu-328 module mounted on RFu Developer Board, MCP9700A analog temperature sensor.
Code for the RFu can be developed using the standard Arduino IDE, with a library available from Ciseco for to allow interaction with the SRF radio module present on the larger RFu module.
The Test Scenario
The aim of achieving a battery life for the sensor of > 1 year is great, but waiting for 12 months to prove both the hardware and software isn’t desirable. So rather than sampling at a frequency of once a minute, the sample frequency is reduced to once every 2 seconds. This means that 1 day of runtime is development mode is equivalent to 30 days of runtime when sampling at one sample a minute.
We record the data sent from the sensor using an LLAP message, using a Raspberry Pi and Slice of radio. We’ve previously covered this in another article. This is then processed using Node-RED and uploaded to Xively to record and plot the results.
We sent data for battery voltage in mV measured using the ATMEGA328′s own supply voltage measurement function, and analog voltage from the MCP9700 to Xively every 2 seconds. Starting on the 1st December 2013.
Here is a screenshot of the xively feed, on Boxing Day (26th December 2013).
At this stage we’re only interested in the being able to run the sensor for more than 1 year on a single set of AA batteries, so the plot above is for battery voltage only. We’ll look at temperature sensing in a future article.
Working left to right on the graph above we’ll describe the date, and size of each voltage drop.
- November 27th – 3019mV Previous version of testing firmware with 20 second sample
- December 2nd - 2956mV Initial drop after replacement firmware with 2 second sample
- December 3rd – 2948mV
- December 6th – 2940mV
- December 8th – 2918mV
- December 16th – 2908mV
- December 19th – 2903mV
- December 25th – 2985mV
- Current Reading (26th Dec) – 2985mV
So, using the results from December 2nd to December 26th, a period of 24 days, we’ve seen a drop of 29mV, or 0.03V.
After 24 days of running at 2 second sample frequency, we’ve seen the supply voltage to drop by a fraction of a volt. Clearly there’s still a lot of life left in these batteries. Whilst the RFu may be getting close to the voltage tolerance of a 16MHz crystal, the SRF module itself is rated down to 2V. Decreasing the sample rate to 60 seconds, will give ~2 years of operations. (24 days *60/2).
So the target battery life is clearly achievable, we’ll begin to focus our efforts on getting actual sensing of temperatures, design of a PCB, and production of documentation in the New year.
Want to find out more then why not get in touch.
You can follow the on-going progress of the sensor documented above by watching the following Xively feed
Here’s a picture of the Sensor in situ
Back in April, Seneye announced that they would be producing a box to allow use of their aquarium sensor without needing a PC.
29/04/2013 After many months of successful alpha testing we are now working on the tooling and beta boards for the seneye web server SWS; however we expect at least 2 months till we have product to ship. The SWS box will allow the seneye device to use your broad band router or switch to manage your seneye device from seneye.me. It totally removes the need for any computer in the home. Uploads will be faster, more reliable and it adds warnings for connection down (power out). There will be add-on modules available separately for Wi-Fi, Ethernet over power and eventually GSM.
If you want to be on the beta test let us know; we will add you to the list and offer you the chance to be the first to own. We will produce a limited amount of SWS for beta testing and will also ask for deposits in a few months. As a seneye beta tester you will receive a small discount on the SWS (for helping us test) and the latest firmware update for your seneye device.
Tip: coming soon is the new seneye web server which is a small upload box meaning no seneye connect software will need to be downloaded for PC or Mac.
Great news for anyone not owning a PC.
So Ciseco were nice enough to send me a Slice of Radio to try out on one of my Raspberry Pi’s. Show as shown above sat nicely on one of the original model B boards.
So what is a ‘slice of radio’, well quite simply it’s an SRF RF module on a carrier PCB that makes use of the serial port on the RaspberryPi GPIO connector.
Rather than try and figure out setting the Slice of Radio up for myself, I decided to follow the instructions provided by Ciseco, here, everything went without a hitch, it really did just work as described, full credit to the Ciseco team on this one.
Within ~10 minutes, I was talking to the SRF board, using minicom, and the extensive AT command set that Ciseco have provided to talk to the SRF, and associated RF boards in their range.
We’ll be following this up, with some practical examples of using the Slice of Radio, including how to build a SRF to Wifi bridge for optimal placement of the SRF master node.
The drive train is responsible for actuating the actual valve body on the radiator. This is typically done by driving a threaded pin, which in turn pushes against the pin of the valve body.
In the image above, the grey knurled collar to the right of the image has a thread of M30x1.5 making it suitable for attachment to Danfoss RA, RAV and RAVL valves. The driven pin is at this end of the assembly.
To the centre of the image, a motor can be seen with 2 wires leaving to the brains of the TRV.
We were lucky enough to find documentation of how the drive unit is constructed shown below.
I’d like to highlight the black gear wheel with three white spots in stage 12 (bild 12) above, this along with the Optoreflexkoppler, the small black chip in stage 16 (bild 16), allows the TRV brains to keep track of the valve position and learn the limits of travel of the radiator valve body itself.
Doesn’t look like too much on the outside. The TRV featured in the image above is a low end device with no radio link.
However, with suitable tools we can take a look inside.
You can now see the anatomy of a TRV.
Over the next few articles we’ll cover what makes a TRV, and include details for the example above.
- Drive Train – Article here
Whilst investigating use of RFM22B / RFM23B as an alternative to RFM12B, I’ve discovered that all three products are End of Life, I’ve contacted HopeRF to see if there are more details available.
Currently the RFM69W is being suggested as replacement.
Why ? Well the RF chip in use in the HopeRF products the Si4431 from Silicon Labs has been similarly been EOL’d
So is there any evidence of RFM products disappearing from the channel, and the answer would appear to be yes.
See the following screen grab from RS’s website.
So what future for cheap wireless sensors ?
Here’s what you get in the kit.
So whats in the kit:
- High quality PCB
- 2 Resistors
- 2 Diodes
- 2 Transistor
- A 3 way screw terminal
- Bi-Stable Relay
Lets start by taking a look at the PCB.
As with other Ciseco products the PCB is of high quality, with a good layout. Note the separation between power section of the relay and the control circuits. This allows the relay to handle 230v although care should be taken when working with mains voltage.
Details on building the kit follow.
There follows a series of photos covering the build of board #2. Board #1 was build very quickly to perform initial design proving tasks and not all connectors or features were available. Board #2 was built with all the correct connectors with the exception, at the time of the extended shield connectors, uSD socket and the real-time clock chip and associated components.
The bare pcb, we’ve got to start somewhere!
Resistors and diode added:
Capacitors and crystal:
Main dip socket and xbee sockets:
The rest of the header sockets:
Electrolytic caps, reset switch, LEDs and voltage regulator (Note this regulator is wrong type and pinout is different to one specified in schematic, hence reason why it looks to be wrong way round to that on the silk screen):
Added ATMega1284P, Wiznet and RN-XV module to show options available:
End view showing LEDs and connectors. Green is power LED, other is a Blue LED connected to PWM capable output:
After the photos were taken the RFM12B module was added and bootloader programmed onto the new ATMega1284P. Further tests are being carried out to prove the design and locate any flaws and improvements that can be made.