3 replies to this topic

[Nevyn]

As part of my re-introduction to electronics I recently decided to renew my relationship with the NE555 timer. After a short while playing with the design of an astable circuit it seemed to make sense to build an application to perform the calcuations for me. Hence the idea for this project was born. The majority of this project is software based. In fact most of the time was spent working on the Silverlight front end which you can find here (please be gentle as the error checking is very rudementary words will certainly upset the system ).

This project has two components, an extension to the simple web server I have previously posted on the project showcase and a Silverlight applicaiton to interact with the user.

The simple web server has been modified to allow the user to send configuration information to the Netduino Plus. It can also act as a simple data logger. This obviously has some restrictions such as the maximum sample rate etc. but is effective enough for my needs at this time.

Interaction with the user is facilitated by a Silverlight application. This has three components each represented by a seperate tab on the interface.

The parameters tab allows the user to enter the parameters for the calculations. The user enters three of the four parameters from R1, R2, C1 and F and the application will calcuate the remaining parameter


When calculating F, the system also allows the user to select a range of values for R1, R2 and C1 producing a table of results. The second tab shows the results of the calculation:


The third tab allows the user to communicate with the Netduino and presents data which has been captured by the board on A0.



If you are interested, the full source code can be found on my blog entry about this project.

Regards,
Mark

15 March 2011 - Replaced links to images with Flickr links.

[Mario Vernari]

Hi Nevyn! Your idea is very nice and it deserves some embellishment, IMHO. Firstly, I've made some effort to understand the sense of the project, because it's a double-function application. In the sense, you made a 555 calculator and an oscilloscope, but this could be used for any kind of signal as long it's bounded in the ADC range. I'd specify also some info about the connection of the 555 output to the Netduino ADC. If you're going to power the oscillator with 12V, you may damage the ADC input. Anyway, that's a very useful app, also for educational purpose. You may offer several kinds of 555 circuit templates and the ability to modify the value of the components by a slider. In this way you may show the calculation result in real-time (e.g. simulating the output on the chart). Afterward the circuit will be built, the ADC could be compared to the simulated wave. Along this way, you may offer also different kinds of circuits (e.g. op-amps). I remember that the filter's calculation and similar were very useful in lab. I didn't check your code yet, but I'll try to do... Tell me if you need some little help from me (as far I can). Cheers Mario

[Nevyn]

Firstly, I've made some effort to understand the sense of the project, because it's a double-function application. In the sense, you made a 555 calculator and an oscilloscope, but this could be used for any kind of signal as long it's bounded in the ADC range.

The concept was to build an application which would perform the calculations for me and then allow me to compare the theory to the implementation.

I'd specify also some info about the connection of the 555 output to the Netduino ADC. If you're going to power the oscillator with 12V, you may damage the ADC input.

If memory serves, the minimum supply voltage for the 555 is 4.5V (I was using 5) and this generates an output equal to the supply so I was already outside the range for the analog input to the Netduino. To get over this I fed the output through a voltage divider. If you look at the range of the values on the chart at the end of the pot you will see that the maximum is under 300 whereas the range for the ADC is 1023.

I like the idea of the dynamic generation of the results and wave form. The application already allows the user to select a range of values and see the results. The image below shows the results when R1 is set to a range:


Going forward, I think the first step is to make the application more robust and get some better error trapping in the system - maybe some validation.

Regards,
Mark

15 March 2011 - Replaced links to images with Flickr links.

Edited by Nevyn, 15 March 2011 - 07:46 AM.

[Mario Vernari]

Mark: your project unleashed my brain!... I'm trying to set up a platform to simulate small circuits using Netduino. Please, be patient. I'll post as soon as possible the project step by step. Cheers Mario