Skip to main content

alcohol sensor (and some patience)

Soldered the alcohol sensor into something that is connectable:


I tried to connect this to the Arduino, as I had the appropriate circuitry, but I did not get any legitimate output from it. 5V going in, 5V coming out with no variations. Nothing seems to be awry in wiring, as the circuit seems to be grounded properly (and the 5V current is flowing). 

There are a couple of potential factors as to why I'm not seeing any results:

- I'm using a 10k ohm resistor, while some guides (and the datasheet for the sensor) asks for 100-200k. However, there seems to be a good amount of people using 10k and getting at least some kind of result. A batch of 100k ohm resistors I ordered is on its way, so I guess I can try with them when they come.

- This site claims that these sensors take 24-48 hours for its signals to be stable. It also tells me that I should not be powering the sensor directly from the Arduino, which I have been doing, out of concern that the power draw of the sensor might damage the board. I did receive the voltage regulator required for a secondary power source, but I'll also need a capacitor and a 9V battery connector, which are both on its way.

Let's hope I didn't get a dud and wait for the parts to arrive.

Labels:

Comments

Post a Comment

Popular posts from this blog

websockets and mobile networks and ssl

Gahhh. Just going to ramble on this one: Websockets is unstable going through cellular networks Searched Google and solution seems to be SSL connections Tried to implement, and it works to some extent,  but realized that I'll have to have both Apache, which was running my web front end, and Tornado both listen to 443 which cannot happen Realize finally that Tornado is a SERVER just like Apache Try to implement web client through Tornado It works but Websocket server and the web client still different instances so still can't have both listen, or that's what I'm thinking but I don't have time to think about it at present. Gotta sleep.
Post a Comment
Read more

duty cycle testing

Now that I saw a physical response, I should try to make it similar to how a servo should be controlled. Servos are actuators that receive (expect) position input (as opposed to motors, which receive speed/intensity input). Simply put, it registers input as pulses, decoding the ratio of high (a "on" signal) to low in a given period as a position value.  A better explanation :  http://learn.adafruit.com/adafruits-raspberry-pi-lesson-8-using-a-servo-motor/servo-motors As I am waiting for my servo to be shipped, I will continue to work with the LED light.  As opposed to my previous setup of having the light turn on every time the request is given, I will have the light turn on and off in a regular pattern until a request is given, upon which the pattern will change for one "cycle" (on-and-off pair). The on-and-off logic (previously the LED control logic) will be run in a separate thread: def dCycle(*args):    global dCVal   ...
Post a Comment
Read more

finally got around to it (nrf24l0+ and servo)

On a previous post , I used the nrf24l01+ wireless chip to communicate between the Raspberry Pi and an Arduino, but only got lights to turn on. I remember being confused as to why servos would not work, and somewhat left it there. I started messing around with it again, and I am concluding that it might have been just a power issue. Here is the servo moving properly: The Arduino is on the ground due to the short length of the wires powering them. Just as a recap, what is happening is: - a C++ program using the RF24 library is compiled in the Raspberry Pi (connected to an nrf24l01+ chip) to broadcast a message. When executed, it will broadcast the message. - the Arduino (connected to another nrf24l01+ chip) programmed to receive messages receives the message, and upon receipt sends a signal to an Arduino that is wired to the servo to move the servo. Two separate Arduinos are used, as it seems that the servo library and the RF24 library do not seem to run properly toget...
Post a Comment
Read more