I am having great difficulty in posting anything that is not straight text – I suspect a WordPress bug (recently upgraded to 2.9) but I cannot narrow it down. It appears to be when I have links to external sites. Wonder if WordPress introduced a new security feature?
Got it – any post created with the twitter upload plugin active and WP 2.9 or greater gets garbled. Disable and delete the plugin, then create new posts – all is good.
Set up with different plugins and theme.
I have been extending my range of inputs to the CurrentCost, Ardunio, Xport pachube logger.
In order to do this I wanted a wireless sensor module.
After looking round I chose the FIO, has an XBEE socket and ATMega168, very little else. Can be powered from a rechargeable LiPo battery.
The next step was to look at the power requirements. I am using a 1000mAH battery and with the normal FIO consumption of 65mA this would last about 16 hours – not very long. After some experimentation I found that if I ran the XBEE in pin controlled sleep mode 2 (less power used than mode 1 at 3.3V) and the ATMega in full sleep I could get the consumption down to 270uA. Switching off the ADC and the analog comparator got this down further to 170uA. Assuming that we have 30 minutes active per day (I’m hoping for much less) this will run for just under 1 month. In practice (this has been in place for the last 6 months) it runs for about 4 months before it needs recharging.
I am using a low value on digital inputs 2 or 3 to wake up the ATMega and then the ATMega wakes up the XBEE.
To be continued …
A lot of devices use XML these days – and parsing the XML by hand is quite complex. I use a CurrentCost CC128 power monitor and also Twitter. Both of these have an XML interface.
Over the last couple of months I have been developing a simple XML parser as an Arduino library – it is table driven and so compact and easily modified. This is now ready for release – you can download it here. The CC-128 example compiles at less than 9kB.
I have included a Twitter API example and also a CurrentCost CC-128 example.
The CC-128 example is being used to provide a data concentrator for CC-128. I am using an Arduino (Mini Pro 328) to take the cpu burden off the main Arduino, processing serial data at 57600 baud takes up most of the power of an Arduino.
Connect the Mini Pro to the CC-128 using GND and CC-128 Tx to Mini Pro pin digital 1. The Mini Pro acts as an I2C slave for the main Arduino (simple connection – just link up GND, A4 and A5 – also 5V if you don’t have a separate power supply).
I have three current cost devices feeding the CC-128 – Electricity, Gas and a light sensor. It should be quite easy to modify the example for your configuration.
Master code to read from the CC128 I2C slave is roughly as follows
CC128Data cc128data; // structure definition is held in the .h file
Wire.send(SNAPSHOT | READALL);
delay(5); // give the I2C transmission and the slave time to deal with request
// 2mS does not work - 3 does - give it 5 to be safe
Wire.requestFrom(I2CADDR, sizeof(CC128Data)); // request data structure bytes from slave device
byte* b = (byte*)&cc128data;
for (int i = 0; i<sizeof (CC128Data); i++)
*b++ = Wire.receive(); // receive a byte as character
I will be writing up another post about the CC-128 data concentrator and the main Arduino, describing how to set up multiple I2C slaves all linked to a central Arduino CPU.
Presents under the tree all ready to be opened after scrambled egg and smoked salmon brunch, with bucks fizz. Nom nom. Despite appearances the tree is vertical – just a weird branch at upper right.
Updated blog to use Ingoal’s Twitter Updater
The Arduino Nokia 3310 shield come from NuElectronics. I have been using this shield with an Arduino Ethernet shield together with Andrew Lindsay’s Nokia 3310 library. I upgraded the library to be compatible with multiple SPI components, you need to bend digital pin 10 so that it does not make contact and then connect it to another spare pin.
Andrew has updated the library based upon my changes, you can download it from here.
This is the current state fo my home monitoring system.
I am working on integrating a camera (pictures visible on a web site), sms and email.
Just got back from Hungary – blogged here.
Now unpacking and back to work.
The code I have been developing for my Current Cost meter updating to Pachube via Arduino with XPORT is ready for sharing.
You can download the code from this link.
Current cost sensors are
0) Main electricity sensor – clamp on incoming live cable
1) Gas pulse sensor – see entry below
2) light sensor – photo resistor (about 2M ohms dark to 100 ohms bright light) as sensor across the channel inputs on the Current Cost dev board.
Current Cost sensors are read by Arduino, displayed on 4×20 lcd module and uploaded to Pachube via Adafruit XPort shield every 15 minutes.