Show Posts
Pages: 1 ... 14 15 [16] 17 18 ... 28
226  Using Arduino / Project Guidance / Re: Has anyone got practical experience of Solar on: May 07, 2013, 06:50:19 pm
Ive made a number of remote operated devices which run off Micros In my case using PICS not Arduinos , but the principle is the same.
You need to know the daily power draw of the device to be powered.
You then need to know the worst case sun hour value for the middle of winter, usually around 2 - 3.
You then have to allow for multiple days of cloudy weather , usually 5 days is a good compromise , but varies somewhat depending on your latitude.
You can then size the battery and the solar panel to suit.
Try and reduce the power draw of the device to an absolute minimum when its not doing anything useful.

227  Using Arduino / Project Guidance / Re: Communicate with third party RF transmitter on: May 02, 2013, 05:45:10 pm
You need to know a lot more about the Transmitter.
How does it send data, what type of modulation is used.
Without an oscilloscope, this will be very difficult to do.
228  Using Arduino / Motors, Mechanics, and Power / Re: Flywheel as quadcopter power source on: May 02, 2013, 03:03:56 am
The other factor thats missing from the demo is how much power was put in to spinning up the flywheel
compared to what was stored.
229  Using Arduino / Motors, Mechanics, and Power / Re: Using solar panel to power small DC Motor 6/9v on: May 02, 2013, 03:00:48 am
Whats the motor going to be powering?
For how much of the day will the motor be running?
Do you want the motor to run in the middle of winter?
All these factors are needed to size the solar panel.
230  Using Arduino / Networking, Protocols, and Devices / Re: Control simultaneously 40 Led DIMMER with RF on: April 30, 2013, 06:32:23 pm
The latency you are seeing is largely caused by the encoder / decoder chips you are using, mainly the decoder.
Its inherant in the way that they work.
You will need some other method for 40.
231  Using Arduino / Networking, Protocols, and Devices / Re: nubee, please help, wanting a simple wireless setup. on: April 28, 2013, 06:23:58 pm
You can buy wireless USB extenders, which will do what you want.
Be warned though, these devices are very expensive.
232  Using Arduino / Networking, Protocols, and Devices / Re: Problem/Question about receiving serial communication from Garmin GPS on: April 28, 2013, 03:07:37 am
Software Serial uses the CPU to calculate the timing of the bits , so it can either receive or transmit but not both at the same time.
When you are transmitting a character, any incoming characters will be lost.
You need to use the hardware Usart in the Micro.
233  Using Arduino / Project Guidance / Re: Grove Temperature and Humidity Sensor shows no value/timeout error on: April 27, 2013, 12:13:53 am
You need a CRO to test the sensor.
Until you verify that the sensor is actually working properly, theres no point in trying to write code to test it.
234  Using Arduino / Project Guidance / Re: Home Alarm - Need a wireless solution to send PIR information to the MCU on: April 26, 2013, 06:21:39 pm
Look at using a SC2262 and a cheap 433 Mhz ASK transmitter to send your PIR data.
They can send 4 bits , which allows for 16 differant states.
You will need a SC2272 to decode the data.
235  Using Arduino / Project Guidance / Re: Grove Temperature and Humidity Sensor shows no value/timeout error on: April 25, 2013, 11:54:49 pm
You need to test the Sensor to make sure its operating properly.
The Sensor is a 1 wire sensor which uses bidirectional data transmission on the data line.
If you pull the data line low for 20 ms and then release it , the sensor will send a binary data stream
which comprises 5 bytes of data.
The sensor normally sends nothing until you ask it to send.
236  Using Arduino / Networking, Protocols, and Devices / Re: Arduino on the Internet. problems with port forwarding? on: April 23, 2013, 07:44:26 pm
Many routers with Nat and port forwarding wont allow an external connection , if it appears to be coming from
inside the LAN.
So, to test that your port forwarding works, you have to test it from outside your lan.
237  Using Arduino / Project Guidance / Re: Wireless USB? on: April 22, 2013, 05:32:15 pm
The problem with running USB over wireless is meeting the USB speed standards.
USBV1.1 which is the slowest, requires 12 Mega bits/sec which is viable using wireless but
very hard to implement.
You can buy wireless USB extenders , but they are expensive .
238  Using Arduino / Displays / LCD displays using the HD44870 , power consumption. on: April 22, 2013, 12:21:31 am
Many of the common 2 X 16 LCD display use this chip.
Does anyone have any ideas of how to reduce the power consumption of the display.
Most of the common displays require around 1 - 1.5 ma without a backlight yet the HD44780 controller chip specs require only 150 ua .
I dont know where the rest of the power goes.
The display Im using only changes its value around once every 1 1/2  minutes so data writes dont occur very often.
Trying to make a small battery powered Temperature sensor , and 1.5 ma
draw kills the AAA batteries.
239  Using Arduino / Sensors / Re: Where to get sensors for weather station? on: April 19, 2013, 04:55:33 am
Do you actually want to make the sensors , or do you want to use existing commercial sensors.
You may be interested in this project.
Its called Weather Station data Logger and it uses an Arduino with a custom shield to simulate an Oregon Weather Station Console and allows
PC monitoring of a wide range of Weather conditions.
It can measure Humidity, Temperature, wind speed & direction , UV , Rainfall,Barometric Pressure.
Ive built 2 Arduino based Weather Shields, and Im now in the process of making my own Temperature / Humidity Sensors using DHT22 sensors.
240  Using Arduino / Project Guidance / Re: Arduino MPPT - Tim Nolan version without battery on: April 18, 2013, 04:49:13 am
The reason that a battery is needed for a MPPT type charger is to accomodate the situation where the power output from the solar panel
is lower than the power required by the load.
Solar panels over the course of a day, provide a varying amount of output power based on the amount of solar irradiation falling on them.
To start a motor which will be the case with a water pump, you need sufficient current to start the motor.
Starting a motor needs far more current than whats required to keep it running.
If the Solar panel has sufficient capacity to provide the current , then as the previous poster has indicated, you dont need a MPPT converter or any kind
of controller.
All you need to do is connect the Solar panel directly to the pump, with just a relay to turn the pump on and off.
If the Solar panel doesnt have sufficient capacity to start the pump, then a MPPT controller without a battery wont help at all.
Pages: 1 ... 14 15 [16] 17 18 ... 28