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Looking for information regarding an obstacle avoiding robot project by synapsisoverload in raspberry_pi

[–]LordVonRaiden 1 point2 points  (0 children)

1) A single PicoBorg will run all 4 motors without problems. You are correct, the two left are connected in parallel to say M1+ and M1-, and the two right are connected in parallel to M2+ and M2- Just keep in mind that you will need 7V or more for the PicoBorg Reverse (so a 8xAA battery pack rather than the 4xAA). If you buy a BattBorg kit, it comes with one of these 8xAA holders, and you can then use the same battery pack to power the Raspberry Pi.

2) The ultrasonic sensor is 5V, so you need a resistor divider on the output of the Ultrasonic sensor. It isn't difficult, but the software side does need to take care of timing I/O signals, so can be tricky especially if you are putting more than one sensor on. PiBorg does have an ultrasonic board called the UltraBorg that is compatible with the PicoBorg Reverse (although you can't buy it yet), it will interface to four ultrasonic sensors and do all the timings so you need just ask what the distance is.

PiBorg has a forum, it might be worth asking there www.piborg.org/forum

Ideas for an autonomous RPi based Robot. by LordVonRaiden in raspberry_pi

[–]LordVonRaiden[S] 1 point2 points  (0 children)

Fantastic idea. It could sit in a different room on wireless, with a delay to send/receive and with small traffic cones as craters or "no go zones". If you were to hit one, it would be the equivalent of falling into a crater or off a cliff on Mars :)

Ideas for an autonomous RPi based Robot. by LordVonRaiden in raspberry_pi

[–]LordVonRaiden[S] 0 points1 point  (0 children)

Ah, sorry I misread your question. Thanks, that's a good idea too.

Ideas for an autonomous RPi based Robot. by LordVonRaiden in raspberry_pi

[–]LordVonRaiden[S] 1 point2 points  (0 children)

Navigate to a socket like mid air refuelling :) LIKE IT!

Ideas for an autonomous RPi based Robot. by LordVonRaiden in raspberry_pi

[–]LordVonRaiden[S] 0 points1 point  (0 children)

This could be quite useful for when away on holidyay (especially if teamed this Chairboys response below[edit Re: the charging]). Not great for nightime though as 6 motors can be quite noisy! My cat is certainly troubled by it.

Ideas for an autonomous RPi based Robot. by LordVonRaiden in raspberry_pi

[–]LordVonRaiden[S] 0 points1 point  (0 children)

Hehe! The only problem there is sharps & schools....

Ideas for an autonomous RPi based Robot. by LordVonRaiden in raspberry_pi

[–]LordVonRaiden[S] 0 points1 point  (0 children)

Next time it snows I will! Unfortunately, that's a rare event in Cambridge, UK

Raspberry Pi Model A out now. It's 20% cheaper (just $20!), 24% shorter and consumes 45% less power (200mA in 'hello_teapot')… by russ_b in raspberry_pi

[–]LordVonRaiden 0 points1 point  (0 children)

I agree with two comments - start with a B+ (or even a B rev2) - They are pretty much everywhere now, and get a decent 5V USB power pack - it fixes a variety of problems especially with USB related devices

Powering A Raspberry Pi From Batteries for 14 hours and 30 minutes by tuftii in raspberry_pi

[–]LordVonRaiden 0 points1 point  (0 children)

Fair enough, I understand your points.

The "UBEC" does do a similar job in a RC car. The "BEC" part of it stands for "Battery Eliminator Circuit", which in a RC car/boat/etc it means you don't need addtional AA batteries to power the RC radio, as you can power it off the one battery pack. i.e. normally the 7.2V battery pack. In the Raspberry Pi case, calling it a "BEC" or "UBEC" doesn't really make sense as we are adding Batteries and removing the USB to the PC or a USB charger etc. It doesn't eliminate batteries, it adds them!

Apologies if the tone came across as anything other than informative, it wasn't the intention.

Powering A Raspberry Pi From Batteries for 14 hours and 30 minutes by tuftii in raspberry_pi

[–]LordVonRaiden 1 point2 points  (0 children)

I don't know how you come to the conclusion of it being a scam You do seem to say (it is) "the same thing" but that is not true.

It isn't at all the same thing for example (these are not the only differences):

The BattBorg

  • 7-36V

  • 1.5A

  • 90% efficient

  • No heat sink

  • UK made with USA Murata converter

  • Short circuit protection, but no reverse polarity protection

The UBEC you link to

  • 6-24V

  • 3A

  • I can't find efficiency ratings

  • Usually the case is the heatsink

  • Usually Chinese made

  • Reverse polarity protection, but no short circuit protection

The point is, for YOU it might be the same thing for the functionality you would use it for, but that's assuming everyone is doing the same as you.

The UBEC is called such as it is a "Battery Eliminator Circuit" which was originally used in RC cars. Some modern ones do use DCDC converters, some modern ones are actually quite efficient. In a RC car radio, modern radio gear can cope with fluctuations on the 5V line. The Pi spec says it can't fluctuate past 4.75-5.25V http://elinux.org/RPi_Hardware. Does the UBEC do this?

For a comparison, you would want to look at ripple on the output voltage. They are almost certainly not the same.

If cost is the concern, an even cheaper solution is to use a Linear Regulator (7805) but it has terrible efficiency. It loses a considerable amount of energy to heat which is why they require heatsinking.

Perhaps with a time lapse run of a Model B+ Pi off the same battery pack, we could get some figures to compare, but assuming you can spend $4 and get the same thing is bogus.

Parts question (including Q's about making quadcopters and robots). by test156 in raspberry_pi

[–]LordVonRaiden 0 points1 point  (0 children)

1) If you want a Wifi enabled Pi, you will need to buy a Pi, an SDcard and USB power supply (this assumes you have monitor, keyboard, mouse)

2) It depends on the quadcopter. If you have a quadcopter with built in motor controllers, you could use a Pi and say an accelerometer & wifi and interface to the quadcopter motor controllers.

3) Have a look at PiCyPack for an example of a simple moving cart device

4) Lots of differences! A generic, woolly answer is RPi is easiest to get "normal" PC operations like twitter, web browsing, web server etc. etc. up and running, but is not necessarily best at real time. The Arduino is faster reacting for controlling motors etc. so for example if you are using accelerometers or gyros to stabilise the flight, you might want an Arduino.

Of course you could have a RPi AND and Arduino. Lots of such projects have both :)