Recent Posts

Pages: [1] 2 3 ... 10
1
   Hello.
  I'm working in a personal project with my car and I'm trying to get RPM information. For that I bought a Serial CAN-BUS Module based on MCP2551 and MCP2515 from SeeeStudio, at https://www.seeedstudio.com/Serial-CAN-BUS-Module-based-on-MCP2551-and-MCP2515-p-2924.html and I'm not getting information from my car. I'm using a teensyduino 3.1 and serial CAN Module.
  I asked for a help on seeed site but I didn't receive any help.
  My car is a Volkswagem Saveiro 2013 and on OBD-II conector doesn't have CAN-H and CAN-L cables, just K-MASS cable, and I'm catching CAN-H, CAN-L cables from instruments' panel.
  On Serial Monitor is showing that is sending information, but don't receive anything.
  Their library works with SoftwareSerial library to create aditional serial port but my teensyduino has three serial ports and I'm thinking that the problem is with their library.
  I'm connecting the module, tx on pin 7 and rx on pin 8 of teensy.
  Could you help me please?
  Thank you.
2
Education and Teaching / Re: mBlock vs Arduino IDE
Last post by lighty - Today at 11:21 pm
Good question  :)

I think it is hard for me to say, since I know programming on a decent level now, I did teach both Arduino and LEGO mind storms, for different audiences.

There are different aspects to it:

What is really good about the drag and drop blocks (blockly, scratch, duinoblocks, whatever) is that it is really easy to explore, as a novice in a certain language, When you don't know the words to express yourself, this makes it easier to find words from this limited list of 'blocks'.

Something like a proper autocomplete might also help a lot with this 'problem', still a user might not know what to start typing, but a exploratory user might get faster results this way.


Another thing is the visual aesthetics of the program. This is subjective, but I could imagine that Arduino code, looks way more scary than a sequence of blocks 'blockly'. I'm not saying that we should always design non-scary looking programming environments, but they should not make it look more complex than it is, but also not less.

Microsoft tried to do this (still inline programming, while having suggestions and making it visually different). But for me it feels painful https://www.microbit.co.uk/app/#edit:095b88c0-b8f0-45c0-c2f6-24d4a842c5cc:wQo27nqYS32Onv2q https://github.com/Microsoft/TouchDevelop and the development will be stoped by the end of this year

Besides all these practicalities ask yourself the question why, why do they learn 'programming/STEAM' is it really to learn c++ (than definitely use Arduino/VScode/Atom). Is it (mechanical) problem solving, make the (mechanical) problems challenging. Is it learning about how the real world works, let them take apart devices, and hack into them... Is it learning that the world is make-able, let them work on changing the current world. Is it data and privacy, let them collect data in the school (in a visible way) and start conversations around it.

PS: Live debugging (seeing where the program is in the code is also super-nice for education, because this makes the whole debugging more visual and it is easier to explain concepts).

PS: Recently I heard that Buddy++ is popular in China to use as Arduino IDE, which indeed has auto-correct and the list of functions on the left.
3
Français / Re: Couveuse d'oeufs (de Pâque...
Last post by BrUnO14200 - Today at 11:21 pm
Salut

Petite MàJ !

J'ai commencé à monter l'enceinte de la couveuse .

L'électronique a avancée également . Tout ce qui est dispo fonctionne pour l'instant : température , PWM pour le ventilo , relais pour la pompe .

J'ai juste eu un problème avec un A4988 qui n'arrive pas à alimenter correctement mon PàP ..bizarre j'ai déja utilisé ce type de module ..

En solution de secours, je vais utiliser un module L298N que j'aime moins car il chauffe bcp durant l'utilisation mais je vais couper son alimentation avec le deuxième relais que j'ai de dispo quand le moteur ne tournera pas .

Du coup , faut que je modifie ma carte ...

Je suis dans l'attente de mes éléments chauffants .



4
Friends, I have an arduino project for the Electronics 1 course.I need to build a robot that moves in an area and sketches the places he goes.This robot will be a robot that escapes both the obstacle and sends the mapping information to the computer or phone.I don't know much about my Arduino shields.I will be grateful even for the slightest help..


How can I do mapping?

How do I send the information to the PC?
5
The datasheet for any relay you choose will have a "mechanical life" rating. That's the rating that the manufacturer is sure it will do, before it starts to be come "unreliable". Most relays will perform many times longer than that rated life. The first datasheet I could find at my favourite supplier has a mechanical life of 1 million cycles, at 180 cycles per minute.

You aren't going to hit the relay this hard. Your heater may switch on twice per hour every hour of the day. You are also switching a very benign load - a 12V signal line is nothing like switching the main power actually going to the fan motor. So you're definitely going to get close to the manufacturer's rating. At that rate you're going to get 57 years of reliable operation out of your relay.

I think the mechanical relay is the best choice for this application. But remember only the tiniest of tiny relays can be driven directly from the Arduino pin. It's best to buy a dedicated Arduino relay shield to take care of this for you.

Solid-state relays are more dependent on knowing the exact load you are switching. An AC relay used on a DC circuit will only switch on and can never be switched off.

Optocouplers are nice and I've used them in a few projects. Their current is usually very low - you need to know if the signal you are switching is using 1mA or 10mA to set up the optocoupler correctly.
6
Sensors / Re: Interfacing a 7 Wire Load ...
Last post by atf_atf_atf - Today at 11:16 pm
Quote
The sense wires are only needed if the leads between the load cell and ADC/microprocessor are long, as they allow the micro to account for the voltage drop in the current-carrying excitation wires.
Thank you so much DaveEvans, so is it safe to continue using the HX711 as per my first design because I need to make sure that the accuracy is maintained across seasons, i.e. temperature changes which might be as high as 25 degrees C from winter to summer? This doubt arises as per this formula from Wikipedia:



It is intended to be used in a food packaging industry where the packages are as small as 25g. Unethical not to consider it I think, even if it is as small a quantity as a fraction of a gram.

Also, the load cell is 15kg C3 class. Sorry, should have mentioned it before.
7
Project Guidance / Re: My own Pinball Machine
Last post by PaulRB - Today at 11:16 pm
Yes, the MCP chips are more capable, but the i2c bus is slower than SPI bus. I am concerned about speed for your project because the sensors may only be triggered for very short period and there is a danger of missing the triggers. Also, I suggested staying with the SPI bus because the other components you want to use also use SPI bus, which keeps things simple.

So if the choice is between mcp23017 and 74hc595/165, I don't know which to recommend.

Why can't you find mcp23s17 or mcp23s08? I can see the dip package versions on eBay.
8
Project Guidance / Re: Changing ground reference
Last post by Enjin - Today at 11:15 pm
I guess I don't HAVE to have it connected, but it really would be nice.

I was also thinking this sounds like opamp territory, but I don't really know much about the with regards to proper specs, wiring

Basically do you powet it with 0-5 creating the limits and then have 17-22 as input voltage?? (Pic attached)
9
The 12v is only the signal on the switch for the central heating system right?  You won't be switching any mains voltage? Mosfet then maybe?
10
It does exactly what you see on the board - it has a reset switch for no particularly obvious reason except "it can", a 3.3 V regulator to supply the ESP-01 and the necessary connections between the pinouts and sockets.

And a "pilot" LED to annoy you.
Pages: [1] 2 3 ... 10