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1  Using Arduino / Programming Questions / Re: Serial read more than 64 bytes? on: August 29, 2014, 01:17:51 am
@ Nick G... +1

2  Using Arduino / General Electronics / Re: Bread Boards & wishful thinking? on: August 25, 2014, 08:36:08 pm
One last item would be replaceable contact strips for the few that will eventually go bad..
If I just had $10.00 for every hour in the past 40 years that I've spent in locating and rewiring or replacing whole breadboards..
My retirement might well be on an island in the Pacific instead of hot and humid Southern California...
Nice dream.. Though.

3  Using Arduino / Programming Questions / Re: Arduino GPS/GPRS real time tracker on: August 25, 2014, 01:03:16 pm
Or another pin for a CD4052 and simply switch between the two serial data streams..
I'd be more worried that the relatively wimpy Uno power supply was adequate to the task of supporting the GPRS module..
I'd also ditch the Adafruit code because that interrupt will occur during any GPRS communications.
the whole GPS data stream repeats every second... So I probably would choose the TinyGPS++ library by Mikal Hart instead.
I've used it many times and it just works. In comparison the Adafruit example is rather clunky.. At best, Great for n00bs? but a big time hog as it decodes all the GPS sentences where two (GGA and GRMC? not sure of the last but it has all the right letters... Perhaps one more for velocity?, I've never needed to use that information so  I never looked into it and this then leaves you about 700 - 800 mS for your own stuff.
just a thought.. My only reservation about the CD4052 is the available drive current considering the possibility of using Long wires on either of the two switches (transmission gates, bilateral) as they are 400 to 500 ohm resistors when on and open when off.
There are several data selectors that are or can easily be made to be that are digital and capable of more drive...
The reason for presenting this was to point to some alternate design methods rather than say it can't be done.
Even gating the GPS off is not an issue for the time in sending a GPRS message unless you are trying to do real time tracking rather than periodic measurements is easily available W/O disturbing the location data stream for very long at all, If any..

4  Using Arduino / Programming Questions / Re: MATHS help reqired for HSI project. on: August 25, 2014, 09:19:34 am
@Paul + 1

5  Using Arduino / Microcontrollers / Re: voltage across LCD(16x2) is fluctuating when connection HC-06 with arduino UNO on: August 24, 2014, 12:42:45 am
The Uno USB protection is a Poly-Fuse.. IT IS a small value resistor effectively... But thermally sensitive. When the ~500mA current is drawn from the USB power source it comes through the Poly Fuse. The current rating is 500 mA to protect your computers USB port... and the max available current from an USB port is.... "500"mA!.....
Your current measurements indicate that it is in it's 'trip' range and what you are seeing is the resistance of the Poly-Fuse as it approaches it's fault current trip point.
It is never a great idea to draw more than ~ 400 mA from a computer USB port as this will cause unspecified results.
Most if not all of your issues are caused by drawing more current than your power (USB Port+ Poly-Fuse limits) supply is capable of.
Adding a large capacitor across the Vcc source is always a Good Idea... but in this case.. May (or should according to the supplied data be of small use) for alleviating your low voltage - over current power supply issues.
As a side note a 7.5V 1A Wall-Wart or power supply is nearly the perfect input voltage for the series polarity protection diode and will cause the least possible heating of the AMS1117_5.0 linear regulator while supplying enough voltage for the series protection diode loss and the dropout voltage of the linear regulator.. I have used them this way for many years with different regulation methods and LDO Linear Regulators..
With consistent satisfactory results..

6  Using Arduino / Project Guidance / Re: Project HELP NEEDED!!! on: August 23, 2014, 08:28:18 pm
without code and external parts spec's.. an accurate diagnosis of your efforts clearly is impossible.
So post your best code  attempt after using the Auto-formatting too (Ctrl +T), a pencil drawing of your schematics and a clear idea of what you need to do..
Or go find the Time Library in the Arduino playground.. There are several code samples that might be applicable..
The Time library can handle repeated alarms... but it might not be a truly great OOBE.. You might have to add some code to "Stitch" it together.
Alternately you could use an irrigation clock.. There are several inexpensive residential devices that can fill the bill, nicely as Mon to Fri and set times usually can be set to eight or more per 24 Hr period per 'zone'.  Many of the available devices are quite versatile as to scheduling
Three zones or area's can handle Weekday, Saturday and Sunday can be silent or used as the situation requires.
Your design looks to require a lot of hardware that apparently you have little experience with..
As a teaching tool your project is an ideal learning experience from several aspects..
How many bells and over what distance and zones.. one minute tardy reminders, are very do-able assuming that Emergency notifications (Fire...  general emergencies) for safety are best handled by devices approved for that purpose. in order to avoid questions of suitability to purpose
Ideal for home schooling and smaller school use.. With the caveats mentioned and Be assured that I've not aware of them all.
Beyond that there are many commercial devices intended to purpose and you may very have to deal with "Approved Equipment sources" to clear the local and state approval/acceptance requirements..
This as a most slippery slope you are on..
How many bells, spread over what area and what other possible uses might this device be responsible for as well??
Some few small thoughts on design parameters and project spec's..

7  Using Arduino / Programming Questions / Re: Problems with firecracker x10 library on: August 23, 2014, 07:42:44 pm
Post your code using the # button above and a copy of the error messages (click on the messages and hit Ctrl C.. First.
Mind reading and crystal balls are notoriously inaccurate.. So WE need to see both or go fishing as none of us are really willing to get into a guessing contest..
Clearly the error I see is on line 37 of the???.h file that you forgot to include.. ..
But I don't ever bet for another persons time and money... So?

8  Using Arduino / General Electronics / Re: Lifespan of old NOS electrolytic capacitors. on: August 23, 2014, 07:32:39 pm
My Standard method for old electrolytics was to reform them as advised above.. But measure the drop across the resistor at the end of the 24 hour cycle and if not zero leave it in place for another 24 hours.. If at the second reform cycle the drop hand't improved it. It was leaky, I'd just toss them..
Devices that passed the DC check were measured for the actual capacitance and If that was within the typical +80/-20% then measure the ESR.. That's a big really important part and failing any of the test's effectively disqualified the part for anything but a door stop..

9  Using Arduino / Programming Questions / Re: how to make a attiny85 go to sleep? on: August 23, 2014, 04:55:53 pm
Yes, a simple search of the forum with the search term "Sleep + Tiny85" returned several answers.. This appears to be good and it is well tested and documented. I know the author.. slightly..

Note: Jacks reference is a GREAT starting point... [Doc]
10  Using Arduino / Microcontrollers / Re: existentialist question: why arduino leonardo Takes that name? on: August 19, 2014, 02:41:28 pm
@KeithRB +1
Too Funny.. ROFL

11  Using Arduino / Microcontrollers / Re: Arduino pro micro atmega32uf no aref pin? on: August 18, 2014, 11:16:43 pm
The LM7805 isn't a good choice for a voltage reference for two main reasons, One is that Accurate ones are scarce. Production starts IIRC @ +/- 5%.
The second is the quiescent current or no load current is about 10 mA.
Good accurate devices such as the Analog Devices part or an equivalentcan be found in several places with prices comparable to Fleabay and one to 3 day shipping.. Microchip sells several devices that should work well and at relatively low cost in 5 piece quantities, I think singles are available but I can't remember for sure and TI will sample as well as will National Semiconductor in 1 to 3 quantities for trivial parts.
As I remember I paid about $0.55 ea for 5 TO-89 MCP1702's and about the same for 5 TO-92 MCP 2703's in addition they are available in 50 mV output voltage increments from ~1V to 5V and at current levels to 250 mA (TO-89) and with voltage inputs from Vout + ~.3V to 16V max. Although this is not a reference device, Per Se, it is an example of what can be found easily and inexpensively including really accurate parts too, Should you require them.
Finally several of the companies offering liberal samples also offer free or relatively inexpensive shipping...

12  Using Arduino / Microcontrollers / Re: attiny 85, any pointers?/ on: August 17, 2014, 10:55:13 pm
In re-reading your last post I realized I'd overlooked one crucial point.. When Stanley forked the nRF lib he rewrote both the Mirf and SPI libs
to accommodate the USI port available from the  Tiny 84 & 85's.  Due to the flash restrictions imposed by the 'small' code space.
This might help you in your search.
An Arduino port of the library. It works with most nRF24L01+ modules.

For this fork, I include :-
* SPI85 libs for attinyXX support
* attiny84 examples codes working with RF24

From xdarklight/arduino-nrf24l01 forks :-
This fork includes the following changes:
* Added support for the SPI85 library on ATtiny85 chips.
* Compatible with ATmega and ATtiny chips (tested with ATtiny85).
* Can connect to devices using the RF24 library by setting
  "Mirf.baseConfig = _BV(EN_CRC) | _BV(CRCO);" before calling
* Reduced binary size.

Other information:
* This library supports changing less popular registers without
  having to "hack" the libraries code. An example for changing
  the RF_SETUP register:
  "Mirf.configRegister(RF_SETUP, _BV(RF_DR_LOW));"


There is code for both the tiny 84's and the 85's in the examples.

13  Using Arduino / Microcontrollers / Re: attiny 85, any pointers?/ on: August 17, 2014, 03:44:19 pm
From Stanley's advice I removed ALL of the nRF24lXX references from my IDE installation [ver 1.05] to avoid possible lib incompatibilities, at Stanley's advice) I then downloaded the nRF24l01 library for the Tiny84 and installed it under Users/../.My Documents/Arduino/libraries/... and was able to compile and program an '84 with the library.. although I never got around to testing it.
I had several issues, initially in comping his code and I PM'ed him about the issues.
His advice is what I mentioned above and it worked.
The '85 is a really nice little controller but there is one free pin... Two IF you disable the reset... I'd advise you to consider the 84... Most highly.
Stanley is approachable... PM him or extract his contact info from the Google search I mentioned and email him...

14  Using Arduino / Programming Questions / Re: calling pinMode in the constructor on: August 17, 2014, 03:08:36 pm
F Malpartida's Liquid Crystal library?.. It does handle several different serial implementations.. I use the one for the I2C implementation  using a PCF8574. It is more than fast enough for my purposes..

15  Using Arduino / Microcontrollers / Re: attiny 85, any pointers?/ on: August 17, 2014, 02:57:31 pm
Yes, A forum member .. Stanley Seow has done it for both the '84 and '85.. Among others, by fixing or rewriting the MIRF class..
My best advice would be to Always remember that "Mr. Google" is your best research friend..
Google sez.. "73400" replies to Stanley Seow.... And this is I think the most salient...,d.cGU
Also search the Forum for nRF24l00 + Stanley Seow, It returns 7 replies...

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