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91
If you treat a 5-wire motor as bipolar but always energize both coils, the centre of each coil must be at
V/2 whichever way round you energize it.  This is not the normal way of driving bipolar motors though.

Of course to treat a 5-wire as bipolar you have to identify the phases correctly.
Hi MarkT! Thanks for your help and explanation. Just to make sure I got the correct understanding - do you mean that supply voltage of 'V/2' volts needs to be applied to the centre of each coil?

I was thinking that supply voltage applied to the centre was typically 'V' volts (rather than V/2), so was confused about the reason for V/2. Is using V/2 related to maximum power handling requirements of the coils?

Thanks MarkT.

 
92
Project Guidance / Re: Delayed shutdown
Last post by lordasriel - Feb 07, 2016, 11:30 pm
This is actually....very good advice.
I could select a nice quality charger, maybe even with the option of charging to a lower level.
I'll start searching.
93
Sensors / what's wrong with my heart rat...
Last post by bmarconi - Feb 07, 2016, 11:29 pm
i was looking at my arduino serial plotter. When I have my heart rate sensor plugged in with no skin contact, and pointed away from me, I have this periodic oscillation. the oscillation pattern is pretty constant, as well as the period (~2seconds).


see the wave toward the right? it looks just like a heart beat... i got all excited over nothing :(


when i unplug everything i get a pretty consistent flat line. when i plug in a piece of wire i pick up noise that's pretty consistent, no oscillatory patterns with a period of 2s.

is it the circuit?
94
Programming Questions / Re: Probleme compilation
Last post by Thomas_D - Feb 07, 2016, 11:28 pm
#include "Configuration.h"
#include "pins.h"

#if ENABLED (ULTRA_LCD)
  #if ENABLED (LCD_I2C_TYPE_PCF8575)
    #include <Wire.h>
    #include <LiquidCrystal_I2C.h>
  #elif ENABLED (LCD_I2C_TYPE_MCP23017) || ENABLED(LCD_I2C_TYPE_MCP23008)
    #include <Wire.h>
    #include <LiquidTWI2.h>
  #elif ENABLED(DOGLCD)
    #include <U8glib.h> // library for graphics LCD by Oli Kraus (https://code.google.com/p/u8glib/)
  #else
    #include <LiquidCrystal.h> // library for character LCD
  #endif
#endif

#if HAS_DIGIPOTSS
  #include <SPI.h>
#endif

#if ENABLED (DIGIPOT_I2C)
  #include <Wire.h>
#endif

#if ENABLED (HAVE_TMCDRIVER)
  #include <SPI.h>
  #include <TMC26XStepper.h>
#endif

#if ENABLED (HAVE_L6470DRIVER)
  #include <SPI.h>
  #include <L6470.h>
#endif
95
Hi,
I am new to Arduino and wanted to use the Ethernet Shield 2 (W5500) for my project. Same as many people, I too had difficulties in getting the right library for W5500.

Now I have updated the Arduino IDE to version 1.7.8 which has a pre-installed Ethernet 2 examples such as Web Server.

However, I am still unable to connect to web using that!!

I have entered the Ethernet shield's MAC address and am entering the IP address as shown by my computer while using port 80.

I have also disabled the SD card by making pin 4 high and setting as output.

Can anybody please tell me what I might be doing wrong here?

Thanks.
96
General Electronics / Re: soldering photo resistor o...
Last post by shadybrady55 - Feb 07, 2016, 11:27 pm
I can just change the great than > to < less than and it works. But I don't fully understand how the LDR works.   I thought more light = higher value for the LDR. That was the case when I had it setup on the breadboard with the resistor and the wire the way they had it.

In this case where I soldered everything on one unit, it has done the opposite and the higher the light, the lower the value.

#feeling perplexed
97
the circuit photo
98
It is also possible some clones knew and used fake chips anyway.  There's no way to find out with so many different clones out there.  The source of my early clones had closed up a couple years ago when eBay suspended him for too many complaint and opened claims.  It would have been about the time FTDI released update that bricked fake chips and it must have caught the seller off guard and he just dropped off the face of the Earth to avoid dealing with numerous return and refund.

One of my older clone from that seller had a fake FTDI chip and it had been a few years before the first problem I experienced that time.  It was way too long ago for return or refund so I just swapped the chip and it has been working fine since then.
99
Programming Questions / Re: debouncing a button code
Last post by GoForSmoke - Feb 07, 2016, 11:27 pm
The code in the original post has a delay() in it.

When you want to have code with independent buttons (controls) and lights (status led, if it blinks the sketch runs) and coordinated real time not turn based actions, you will learn why wasting 80,000 CPU cycles doing nothing while waiting sucks the response right out of your app.

Checking current to previous state is for Change Detection. Only change is interesting here. Did the switch change?

You can differentiate between the pin, the real hardware and the abstract simpler "button".

The pin connected to a contact switch is messy making and breaking contact. Have one piece of code watch it go through the bounce until the pin hasn't changed state in some period of time, I find if it doesn't change for 2 ms, the pin is stable -- it is the Stability to look for, change the value of Button when the pin is stable. Button value is for the process code, pin should be hidden inside the button code. You need examples?

Tip:
I keep my current and previous states in the same byte as bits 0 and 1. Before every read I clear off bits 1 to 7 (mybyte &= 1) then shift bit 0 into bit 1 (mybyte <<= 1) and finally add the digital read (must be 0 or 1) and have my new current and previous states value.
0 is LOW->LOW
1 is LOW->HIGH
2 is HIGH->LOW
3 is HIGH->HIGH
It works great with switch-case. Current state is (mybyte & 1).
100
Tutoriels et cours / Re: Découverte de l'ESP8266 et...
Last post by atrakeur - Feb 07, 2016, 11:27 pm
Je suis d'accord que l'intérêt est limité mais comme précisé dans l'article, il s'agit d'une première prise en main.

Je ne sais pas si tu à lu mon article mais dans la dernière partie, j'évoque les limites des commandes AT et je renvoie vers un autre qui explique comment flasher l'ESP pour utiliser un firmware plus évolué.

Encore une fois, j'essaye de fournir des ressources complètes et fiables (en français) aussi bien sur des choses basiques que sur des choses plus évoluées. Après si tu as des éléments précis que je peux améliorer ou des sujets que je pourrais couvrir, n'hésite pas à m'en faire part! ;-)
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