Go to advanced search

by fixitsan
Wed Oct 23, 2013 6:15 pm
Forum: Advanced users
Topic: Raspberry vs Arduino
Replies: 2
Views: 1114

Re: Raspberry vs Arduino

Do yoiiu want the device holding the DB to be available via the internet, by wifi ? Added to files already in the FAT format on an SD card....or what about USB stick ? Maybe yoiui want to show the data on a screen in a graphical form, using a GUI ? The Arduino is difficult to deal with when you star...
by fixitsan
Wed Oct 23, 2013 1:23 pm
Forum: Other projects
Topic: 12v Li-ion charging circuit?
Replies: 14
Views: 6951

Re: 12v Li-ion charging circuit?

Okay, then yoiu just need a 'step down' power supply. A switched mode step down regulator is better than a linear regulator because it is so much more efficient, wasting much less energy as heat. There are plenty to choose from on eBay, which take upto 30V input and buck it down to 5V. They only cos...
by fixitsan
Wed Oct 23, 2013 5:51 am
Forum: Other projects
Topic: OBD2 Ford Focus DPF
Replies: 8
Views: 13542

Re: OBD2 Ford Focus DPF

Hi Squirrel, thankfully the MOT testers use their intelligence and don't fail a car which is missing it's dpf. The law stipulates a maximum smoke level and if the car passes then it passes. It is not the same issue as the recently introduced legislation which covers the removal of catalytic converto...
by fixitsan
Wed Oct 23, 2013 5:28 am
Forum: Other projects
Topic: 12v Li-ion charging circuit?
Replies: 14
Views: 6951

Re: 12v Li-ion charging circuit?

A quick look on ebay and yoiu can find 'lithium cell chargers which delivery upto 1A, and switched mode power supplies to output 12V But now I've said that I realise you haven't mentioned what the configuration of your battery is, it's voltage, and what voltage you have available for charging it. If...
by fixitsan
Sat Oct 19, 2013 9:31 pm
Forum: Automation, sensing and robotics
Topic: remote web based interface (Klone ?)
Replies: 1
Views: 615

remote web based interface (Klone ?)

I'm building an application whichuses the Pi to serve RSS feed data to a digital display. The configuration of which feeds to retrieve, how often to look, and so on, is all stored as a few fields in a local files. As an ideal goal I would like to give local network access to the contents of those fi...
by fixitsan
Sat Oct 19, 2013 10:18 am
Forum: Other projects
Topic: OBD2 Ford Focus DPF
Replies: 8
Views: 13542

Re: OBD2 Ford Focus DPF

I have Alfa Romeo 159, which had similar dpf problems. Probably the best solution for a dpf is to drill it, to only a shallow depth, at the rear(exit side). This will unblock the channel caps , because the construction is that of a wall flow filter. Since doing that I experimented some more, and dri...
by fixitsan
Fri Oct 18, 2013 6:56 pm
Forum: Other projects
Topic: (?) Wall clock + RSS with 32x32 LED Matrix
Replies: 1
Views: 2256

Re: (?) Wall clock + RSS with 32x32 LED Matrix

I'm working on a similar project. Getting the RSS is easy as Pi ;) I used the urllib module and just opened the page required, saved the results of read() to a string and then parsed out the fields I want to use. I'm going to eventually use 14 segment giant sized B7971 neon based 'nixie' tubes from ...
by fixitsan
Thu Oct 17, 2013 8:29 am
Forum: Other projects
Topic: Safely discharge a LiPo cell
Replies: 3
Views: 1098

Re: Safely discharge a LiPo cell

Sounds like you're well protected !
by fixitsan
Wed Oct 16, 2013 8:13 pm
Forum: Other projects
Topic: Li-ion batteries surcharge and discharge protection
Replies: 2
Views: 1147

Re: Li-ion batteries surcharge and discharge protection

It's difficult to see what configuration the cells are...it looks like there are 5 cells, but maybe there are 6 and one is under the pcb ? Anyway, you must replace the electronics, with things like these http://www.ebay.co.uk/itm/PCB-Charger-for-4-Packs-3-7V-Li-ion-Li-Lithium-18650-Battery-Rechargea...
by fixitsan
Wed Oct 16, 2013 8:07 pm
Forum: Other projects
Topic: Safely discharge a LiPo cell
Replies: 3
Views: 1098

Re: Safely discharge a LiPo cell

I can validate those numbers. I shouldn't worry about the resistor temp, and they all have different temperature characteristics anyway. Monitor the battery temperature though. I think staying below 40 degrees C is a sign that they're happy enough, and I would be surprised if the cell temperature ro...
by fixitsan
Wed Oct 16, 2013 6:56 pm
Forum: Advanced users
Topic: Yet another battery thread.....
Replies: 10
Views: 5768

Re: Yet another battery thread.....

The simple answer unfortunately is that there is no simple answer. If you're adaman that you'll be powering the Pi from the second battery then you need to recharge that battery while the car is being driven (trying to charge it while the car is stationary amounts to simply powering the Pi from the ...
by fixitsan
Tue Oct 15, 2013 8:12 am
Forum: Advanced users
Topic: Yet another battery thread.....
Replies: 10
Views: 5768

Re: Yet another battery thread.....

You could power down the GPS, only turning it on in the alarm state to begin outputting position coords for tracking purposes. It might even be better to use a bespoke alarm system, one with a low current drain designed for the job - most of them have outputs which switch on activation, so you could...
by fixitsan
Mon Oct 14, 2013 8:56 pm
Forum: Advanced users
Topic: Yet another battery thread.....
Replies: 10
Views: 5768

Re: Yet another battery thread.....

I refer you to the master of battery powered Raspberry Pi - the high altitude helium balloonist, Dave Akerman: http://www.daveakerman.com/?page_id=1294 That's excellent real world info. Getting the current down to 100mA seems almost realistic, which is 2.4Ah per day. Over a period of 10 days that's...
by fixitsan
Mon Oct 14, 2013 7:35 pm
Forum: Advanced users
Topic: Yet another battery thread.....
Replies: 10
Views: 5768

Re: Yet another battery thread.....

What is your worst case scenario ? For me it would be the car left for 10 days while I go on a holiday. The whole point of an alarm is to protect the car while you're not there, so an alarm which flattens the battery a few days in would be of little use. I drive an Alfa 159, which are notorious for ...
by fixitsan
Mon Oct 14, 2013 7:09 pm
Forum: Beginners
Topic: How to store POST forms and field data ? (baseHttpServer
Replies: 0
Views: 299

How to store POST forms and field data ? (baseHttpServer

I have a need for some very basic local network application control connectivity. I want to give my project a browser based front end, on a Pi which will operate headlessly, with a wifi dongle. It will make intermittent connections to the 'net to grab RSS feed data. I would like to make a small fron...
by fixitsan
Tue Oct 08, 2013 2:53 pm
Forum: General discussion
Topic: USB Flash Drive 24/7 read/write
Replies: 17
Views: 7000

Re: USB Flash Drive 24/7 read/write

I was reading about a similar issue somewhere else recently The bottom line was to make sure you write to unused space as much as possible, which in your case would mean something like don't delete everything as often as possible, just when you absolutely have to, and spread the wear over different ...
by fixitsan
Sun Oct 06, 2013 1:17 pm
Forum: Beginners
Topic: Powering raspberry pi portable?
Replies: 1
Views: 435

Re: Powering raspberry pi portable?

The power supply probably can power it, but it might be incorrectly labelled. What you need to know is the maximum current the supply can provide from each output. It lists the outputs in units of mAh , when it should be mA. At a guess it is about 3A for 12V and 5A for 5V (both of those seem a bit h...
by fixitsan
Sun Oct 06, 2013 12:59 pm
Forum: Beginners
Topic: Power supply
Replies: 9
Views: 1543

Re: Power supply

A usb car charger is similar to a power bank, but requires an input voltage of 10V-12V You'ld need to have enough voltage from whatever batteries you will have to buy, to provide the minimum input voltage requirement of the USB charger (I guess over 10 volts) So after you buy the car charger you'ld ...
by fixitsan
Fri Oct 04, 2013 7:36 am
Forum: Beginners
Topic: Battery Power for Portable Pi
Replies: 9
Views: 1352

Re: Battery Power for Portable Pi

Same topic came up here http://www.raspberrypi.org/phpBB3/viewtopic.php?f=91&t=56825 The bottom line is that it's better to use switch mode supplies rather than resistive droppers or linear regulators. The RC battery packs in the range of 7V-10V are readily available, cheap, in a variety of capacities
by fixitsan
Thu Oct 03, 2013 4:16 pm
Forum: Beginners
Topic: Open Collector to GPIO Pin
Replies: 28
Views: 11000

Re: Open Collector to GPIO Pin

I don't know about the mulktimeter being the cause, maybe if it were set to the resitance range and it leaked current onto the lines. one question though, you do always have both units on the same ground don't you ?: A poor quality ground connection between them could easily explain some drift. With...
by fixitsan
Thu Oct 03, 2013 12:48 pm
Forum: Python
Topic: quadrature problems
Replies: 18
Views: 4770

Re: quadrature problems

I always used the state table idea, even for a rotary encoder switch, but recently I ried this for a switch (Is the OP using a rotary switch or is he continually mesuring rotation on a shaft ?) For a switch you often get 4 state changes per detent and 12 detents per rotation is typical. You usually ...
by fixitsan
Thu Oct 03, 2013 12:30 pm
Forum: Beginners
Topic: Help me . . .
Replies: 8
Views: 1139

Re: Help me . . .

I had a problem SD card (2 actually). I couldn't get a proper installation working on an 8GB or a 16GB card. The power led was on (and the green led was very very dim) My solutions was to use (Win XP) Start> Control Panel>Administrative Tools>Computer management>storage>disk management. *MAKE SURE* ...
by fixitsan
Thu Oct 03, 2013 9:02 am
Forum: Beginners
Topic: Open Collector to GPIO Pin
Replies: 28
Views: 11000

Re: Open Collector to GPIO Pin

I know you don't want to , but I would add another pullup, at least just on croc clips for now somewhere on the alarm line. Although the output is open collector, there may also be a diode across the transistor, there may be an LED and resistor wired across the same pins to show when the alarm outpu...
by fixitsan
Wed Oct 02, 2013 7:21 pm
Forum: Beginners
Topic: Need help choosing a Normally Closed, 9VAC relay.
Replies: 19
Views: 3382

Re: Need help choosing a Normally Closed, 9VAC relay.

Don't forget the reverse biased diode across the relay, A 1N4001 would
img019diode.JPG
img019diode.JPG (34.95 KiB) Viewed 3360 times
do
by fixitsan
Wed Oct 02, 2013 5:20 pm
Forum: Beginners
Topic: Battery Powering the PI
Replies: 10
Views: 2290

Re: Battery Powering the PI

Traditionally, BEC = Battery Eliminator Circuit, which allows the radio receiver to be powered from the main motor battery and not a separate 3xAA battery pack uBEC, probably means microBEC. It's just a twist on the battery eliminator idea. Switch mode supplies are so much more efficient than linear...

Go to advanced search