Toys for arduino based add-ons

[Dave_D]

Anyone had a play with these? 

looks interesting for arduino I/O stuff... only 6 quid on fleabay.

[fireshipjohn]

Hi,

Yes, but a 6 quid all I see are the cases, were up to around 13 quid for the real thing, or 18 quid for the case included. Still seems a good deal for tinkerers!

John

 

[Dave_D]

ahhh... place i ordered mine from had them at 6 quid yesterday... i paid 8

 

[Gina]

Cheapest I can find on ebay is £15 for the kit plus £12 for the case - total £27   Bit more than £6!!

[Gina]

Amazon UK have the kit at £18.95 guaranteed genuine and the case at £6.98 - total just under £26.

I have an oscilloscope with LCD display but it's only small and quite difficult to see.  This kit has a far bigger and better display and looks very useful.

[ringz]

My oscilloscope is an ancient Tektronix that I bought from a friend for £5

[Gina]

I've made a couple of oscilloscopes in the past - one with valves and one with transistors in both cases using an electrostatic deflection cathode ray tube - ex radar type.  We used Tektronix scopes at work many many years ago.

[Gina]

I've ordered the kit from Amazon - due to arrive Thursday.  I can 3D print a case.

[Icosahedron]

IMHO this is a toy. Bandwidth is everything as oscilloscopes go and this device does not deliver. If you have to buy new: Hantek 6022BE, 2 channels with probes, 20 MHz bandwidth for £37.

[astromerlin]

1 hour ago, Icosahedron said:

IMHO this is a toy. Bandwidth is everything as oscilloscopes go and this device does not deliver. If you have to buy new: Hantek 6022BE, 2 channels with probes, 20 MHz bandwidth for £37.

Compared with a proper ocilloscope, a toy maybe. With most of the current projects I'm working on it would be handy to use a scope, my 200mhz scope is the size of a suitcase and difficult to lug about. The Hantek would still need a laptop and the usual psu,cables a place to lay it all out etc..

So a battery powered scope the size of your hand with it's own screen seems very attractive as long as you're aware of the limitations. 

[Gina]

Yes, that's the way I see it.  I often find I want to watch a DC voltage or a low frequency waveform eg. a PWM output or stepper motor pulses.

[astromerlin]

2 hours ago, Gina said:

I've made a couple of oscilloscopes in the past - one with valves and one with transistors in both cases using an electrostatic deflection cathode ray tube - ex radar type.  We used Tektronix scopes at work many many years ago.

I still have a Tektronix scope, it still works although I dont use it mainly because it's the size of a tea chest so it resides in my cupboard of "It might be worth something one day" items.

[Dave_D]

"Yes, that's the way I see it.  I often find I want to watch a DC voltage or a low frequency waveform eg. a PWM output or stepper motor pulses."

And thats all i want/need so no point paying more.

Just checked fleabay and oh bum... http://www.ebay.co.uk/usr/ay2kkl?_trksid=p2057872.m2749.l2754

This doesnt look good :/ wasnt like this on monday so fingers crossed my item was actually sent.

 

[Gina]

Oh dear, that doesn't look good   I'm always wary of buying from someone I haven't used before and always check the feedback.  Not too bothered about anything under a tenner though.  If Amazon have the item at similar price or just a couple of pounds more I tend to buy from them.  OTOH I have had undelivered items or other problems with ebay but these have been sorted out to my satisfaction - I pay by PayPal and they have handled my complaint at times - good service

[Dave_D]

4 hours ago, Gina said:

Oh dear, that doesn't look good   I'm always wary of buying from someone I haven't used before and always check the feedback.  Not too bothered about anything under a tenner though.  If Amazon have the item at similar price or just a couple of pounds more I tend to buy from them.  OTOH I have had undelivered items or other problems with ebay but these have been sorted out to my satisfaction - I pay by PayPal and they have handled my complaint at times - good service

Yeah i always use paypal. The 'dispatched' icon went up almost 2 weeks ago so fingers crossed. Maybe they were giving up selling and flogging stuff off cheap, which could explain why it was 8 quid, and 6 quit a day later. Still... not gonna get all maudlin over it

[Gina]

My kit complete with instructions came this morning and looks really good   The Y sensitivity and timebase ranges exceed the handheld oscilloscope I bought some years back from Maplin. 

• Max sampling rate :- 1M samples/sec
• Anologue B/W :- 0-200KHz
• Y range :- 10mv-5v / div
• Max I/P voltage :- 50v with 1x probe
• I/P impedance :- 1MΩ/20pF
• AC or DC input coupling
• Resolution :- 12 bits
• X display :- 1024 points
• Timebase range :- 10μs - 500s / div
• Trigger modes :- Auto, Mormal, Single Shot
• Power :- 9v DC (8-12v)
• Current :- 120mA
• Dimensions :- 117 x 76 x 15mm
• Weight :- 70g (without probe)

Also, not mentioned in the spec but can be seen from the photo :- Screen size 12 div (timebase) x 8 div signal. 

[Dave_D]

On 08/07/2016 at 12:36, Gina said:

My kit complete with instructions came this morning and looks really good   The Y sensitivity and timebase ranges exceed the handheld oscilloscope I bought some years back from Maplin. 

• Max sampling rate :- 1M samples/sec
• Anologue B/W :- 0-200KHz
• Y range :- 10mv-5v / div
• Max I/P voltage :- 50v with 1x probe
• I/P impedance :- 1MΩ/20pF
• AC or DC input coupling
• Resolution :- 12 bits
• X display :- 1024 points
• Timebase range :- 10μs - 500s / div
• Trigger modes :- Auto, Mormal, Single Shot
• Power :- 9v DC (8-12v)
• Current :- 120mA
• Dimensions :- 117 x 76 x 15mm
• Weight :- 70g (without probe)

Also, not mentioned in the spec but can be seen from the photo :- Screen size 12 div (timebase) x 8 div signal. 

you gonna do a quick review when you built it?

[Gina]

Oh yes   May also take photos as I build it.  I think I'll make it a project shortly - make a change from messing about with 3D printers  

I might design the case to accomodate a 9v battery and/or an LM317T to take 12-24v and provide 9-10v for the oscilloscope.  I must calculate how long a PP3 battery would last.  Unfortumately Li-Ion batteries are 3.7v ie. a pair gives 7.4v and less than the 8v minimum spec for the supply voltage.  Three would give 11.1v which would be fine except that charger I have charges two at a time.  I guess I could use 4 at 14.8v and drop the voltage to under 12.

[Gina]

Been looking at the discharge curve of various types of batteries both primary and rechargeable.  A nominal 9v battery drops to 8v very quickly so this is not a viable option despite what the blurb says.  A 9v PSU would be alright but I would prefer to have a self-contained unit with no external connections to transmit interference to the oscilloscope other than the test probe.

[ringz]

what about a cheap boost converter, that should be able to power the scope from 2 LIPO cells. They are quite efficient these days.

Like one of these for example. http://www.ebay.co.uk/itm/XL6009-DC-DC-Voltage-Step-Up-Boost-Converter-replace-LM2577-3-32v-input-UK-Fast-/400858208676?hash=item5d5502d9a4:g:ADoAAMXQstJTlgtv

[Gina]

That looks pretty good   Cheaper than the cost of the third cell.  I'll give it a go - thank you   I've used step down switching regulators like that before but not step up.

Edit... Ordered a couple to play with

[Gina]

I've started building this kit but I think I'll start a new thread as I don't consider this as a "toy" but as a tool!

The resistors are very small and the colour coding is not the familiar E24 range but seems to be a 3 figure value plus multiplier etc.  Even with reading glasses and a 3x illuminated magnifier I find the coding hard to see so I took the advice and measured each and every resistor before fitting.

Another reason for starting a new thread is that I intend to design and print my own case and incorporate a rechargeable battery so that this becomes a fully fledged test instrument which can be used in the field with battery powered equipment as well as indoors on the work bench.

[Gina]

Resistors soldered in.

[Gina]

I shall be posting further progress reports and photos in my own thread :- Digital Oscilloscope for Testing & Debugging Astro Remote Controls

[MarkyD]

15 hours ago, Gina said:

Another reason for starting a new thread is that I intend to design and print my own case and incorporate a rechargeable battery so that this becomes a fully fledged test instrument which can be used in the field with battery powered equipment as well as indoors on the work bench.

I personally would not have a LIPo battery permanently installed in the case to charge.  These should be charged with a dedicated balance charger in a fire proof container or as I do in a clay wine cooler and if it looks iffy, puffed or the cells are way out of balance - outside on a concrete block.  They can go up in flames with no warning.  Equipment that does have LiPo as a power source usually has a dedicated internal charger/balance circuit built in

LiFe is a slightly safer route as they are less volatile and more tolerant to imbalance.  When I charge my RC planes any LiPo I take out to charge.  NiMh and LiFe I charge in the model itself occasionally performing a balance charge on the LiFe.  LiPo is always balance charged - My charger doesn't allow a LiPo unbalanced charge for safety.  I also store my LiPo's in an ammunition Box.

http://www.revolectrix.com/pl6_description_tab.htm