Traveling Tech Guy

Hi,
Still messing about with my Sensors project. Reminder: light sensor + temperature sensor + LCD - posting to Pachube.

Everything works well now, and updates the Pachube feed correctly. My next step would have been to use Szymon's shift register idea, to go down from using 10 pins for the LCD to 3 pins.

Only while taking a Youtube video of my creation, I noticed (and documented) an undesired behavior: if I shine a bright light at the light sensor, the temperature drops considerably (from 20C to 14C) and jumps back up when I move the light away.

Logically this has to do with resistance (as the resistance in the light sensor grows, it lessens in the temp. sensor), and with some co-dependency in the way I wired the circuit. But I'm not experienced enough to find the root cause.

So here's a Fritzing diagram of my board (again, pardon the wire mess and 2 boards - it'll hopefully go away soon). The two sensors are on the lower left, and are connected as follows:
- TMP36 temperature sensor: right leg -> GND; middle leg -> analog1; left leg - Netduino 3.3V
- CdS light sensor - right leg -> Netduino 5.5V; left leg -> analog0 + 1kΩ resistor to ground

 Sensors_bb.png   106.4KB   52 downloads

I figured since one sensor goes to 3.3v and the other to 5.5v they are separated. But maybe I've mixed the GNDs?

The code, as well as the full Fritzing file, can be found on github. The video can be found on Youtube (the effect can be seen at 1:48 into the 3 minute video).

As always, any help appreciated. And as always, I'll learn
Thanks!
Guy

PS: Fritzing question: I have this 330Ω resistor connected to the LCD at the lower part of the screen. Fritzing shows it as a 4-ring orange-red-brown-gold, while in reality it's a blue 5-ring orange-orange-black-black-brown. I guess they amount to (almost) the same thing, but how can I tell Fritzing to draw the right one?

Hi all,
I have a simple application that uses a light sensor, a temp sensor and MicroLiquidCrystal library to display the results and save them to an SD card. Everything works great.

I was hoping I could send the 2 sensor results to a Pachube feed. I downloaded the Gsiot PachubeClient and added it to my project. It compiles well. But when I try deploying, I get a generic error

An error has occurred: please check your hardware

and an error in

Microsoft.SPOT.Debugger.VsProjectFlavorCfg.Deploy()

.
No amount of restarting, re-connecting the USB, or even erasing the board helps.

After looking around, I found this thread, suggesting it might be a program-size problem. And indeed, if I remove any reference to the Gsiot DLL, the application can be deployed.

My questions are (in order of light to hard):

• How much space do I have to deploy to? (Netduino Plus (v4.1.1.0 b1))
• How/where in Visual Studio 2010 can I find out the total size my application compiles to?
• While I did include the DLL for Gsiot, I just added the MicroLiquidCrystal project to my solution. Will compiling it and just adding the release version of the DLL mean a smaller sized application?
• What other code-minimization techniques can I use?
• Is what I'm trying to achieve (sensors + LCD + SD card + network) even possible?

This size limit takes me back 20 years to my Assembler days (and even then, I wasn't that great at it ). Any help is appreciated!

Thanks,
Guy

PS: for internet connection, I'm using the Asus WL-330gE as an adapter - so no additional components and or code are involved.

Ok, making some progress. Following great forum advice, I now know how to use a dual-color LED, and I finally got my LCD screen working.

As a next step, I tried combining the 2 programs, completely forgetting the hardware side of things - both programs were using the same pin (D12)!
Of course, I found it the hard way, getting an exception thrown somewhere in the MicroLiquidCrystal code. I'm using a bread board, and thought I could just plug in the LED to a row connected to the pin, but the pin is already in use by the LCD.

Clearly, I'm missing a key piece in electronics, or hardware programming. The LCD, as wired now, uses almost all of the digital pins (2-12 - see post for list). I want to move forward and start wiring sensors, some LEDs, maybe a button or two. But if I can only have one leg connected to one pin - I'm out.

What do I need to do to be able to use the LCD as it is wired right now, but continue to add components? Do I have to use the analog pins? And what happens when they run out?

Thanks,
Guy

Hi,
A friend handed me his "old" (2+ years old) Garmin Nuvi (not sure of the model number).
I took it apart, having nothing better to do with it. I found the following:

• Touch-enabled color LCD (image 1)
• GPS sensor (image 1)
• SD card reader (image 2)
• Unidentified component - possibly CPU + storage? (image 2)
• Speaker w/ connector (image 3)
• 3.7v / 1.25Am rechargeable Li-Ion battery (image 4)

My question is: is there anything in here I can re-use/re-purpose to work with my N+?
Is it even worth the time and effort, or should I just look for similar 'virgin' components?

Thanks,
Guy

Google just (I/O day 1, 5/10/11) announced the "Android Open Accessory Development Kit" (ADK for short), that will allow

external USB hardware (an Android USB accessory) to interact with an Android-powered device in a special "accessory" mode.

They are providing a software and hardware (I swear the link to the Japanese company is taken directly from Google's page ) that will use an Arduino board + shield to communicate with Android 2.3.4 and higher devices.

The myriad of possibilities of using my N+ with my phone, if possible, is staggering. This could bring a new level of network, location and sensor integration.

I have not followed on all the board's hardware requirements (voltage, connections etc.). My questions are:

• Will I be able to use the Netduino+ I have to communicate with my Android devices?
• Will the NETMF environment be agnostic enough to allow integration with the ADK?
• Will I need to buy that special Arduino shield, and will that be compatible with the Netduino?

Hoping for good news

Guy