Another flashmeter

Hi everybody.
As I told Thierry yesterday, I am going to write in english as my french is almost forgotten
I am going to build the flashmeter. As I have already made arduino circuits, I have at home some components that might be useful... I'd like to check with you.
First, I have an arduino nano that already comes with an usb... May I use it instead the arduino mini+FTDI?
http://www.ebay.es/itm/Mini-USB-Nano-V3 ... 1190208618

Arduino nano

IMAG0312.jpg (306.26 Kio) Consulté 8419 fois

I case I needed to buy a mini arduino... could I use to load the program a "usb to serial" that already have to connect an arduino ethernet (I attach a picture) instead the FTDI?

Poosible alternative to FTDI

IMAG0311.jpg (268.08 Kio) Consulté 8419 fois

I also have some bluetooth modules. I think the same type you propose, but the pin names are different... I attach a few pictures to confirm.

Bluetooth

IMAG0315.jpg (293.26 Kio) Consulté 8419 fois

That's all for the moment.
Thanks!

[ThierryD]

Hi and welcome on the forum,
I suppose that you are Juan ?

- For the Arduino, it is not possible to use another Arduino that Arduino pro mini 5V Uc368 for some reasons.
The PCB is designed only for Arduino Pro mini.
I use some instructions (direct acces registry) only for Pro mini.

-For the FTDI module, I don't see the pin DTR and CTS, I suppose that is not compatible (see my picture for the good pins).

-For the Bluetooth module, I think that is possible but the pins has not at the good position (use wires for change pins)


But if I search on Ebay (include price and shipping):
- Arduino pro mini = 1.45 Euros (exactly the same model that I use) : http://www.ebay.fr/itm/Redesign-Pro-Mini-atmega328-5V-16M-Replace-ATmega128-Arduino-Compatible-Nano-/311450780945?hash=item4883e9c511:g:j5QAAOSwFnFWAj-T
- FTDI module = 1.63 Euros : http://www.ebay.fr/itm/FT232RL-3-3V-5-5V-FTDI-USB-to-TTL-Serial-Adapter-Module-for-Arduino-Mini-Port-/351667288290?hash=item51e100f8e2:g:L5AAAOSwmmxW1kDH
- Bluetooth HC-06 = 3 Euros : http://www.ebay.fr/itm/HC-06-4-Pin-Serial-Wireless-Bluetooth-RF-Transceiver-Module-For-Arduino-H-/281900027386?hash=item41a28d0dfa:g:OokAAOSwKtlWiOoc
- Mini PIR = 1.40 Euros : http://www.ebay.fr/itm/Mini-HC-SR505-Infrared-PIR-Motion-Sensor-Precise-Infrared-Detector-Module-/272041590306?hash=item3f56f13e22:g:y~UAAOSwT4lWRX1m

Recycled components are not a good idea :
- Compatibility problems
- Difficulty to find your problem if the Flashmeter not work after build
- ...




NB: If you don't find with a good price the resistor of 100K 0.5%, I have found this (2.01 Euros + shipping 2.55 Euros for 5 resistor, it is very expansive but if you don't find a low price, you could buy it) :
http://www.ebay.fr/itm/5-X-RESISTOR-100K-0-25W-0-5-50PPM-Part-MCMF0W4DF1003A50-/390614557577?hash=item5af2712389:g:v58AAOxyDEVSa75x
This resistor is only a resistor with tolerance <= 1%, good tolerance is 0.5% or very best 0.1%

For the 3.3 / 5 V boost converter, you can found it on website : solarbotics.com/product/18888
5.50 $ + shipping to spain 9.02 $
Lipoly website is down and if you buy this shield directly at CircuitAtHome, the shipping price is very expansive.

Regards,
ThierryD.

[ThierryD]

Hi,
on Ebay I have found a small DC-DC boost converter for a small price : 2.75 Euros (with shipping)
http://www.ebay.fr/itm/mini-dc-dc-Converter-0-8-5V-to-DC-5V-Step-UP-Boost-Module-for-Breadboard-Arduino-/271734570473?hash=item3f44a47de9:g:cfoAAOSwu4BVpSJK
It is compatible with the Flashmeter (pins and size)


ThierryD.

Hi again. I am looking for the photodiodes on ebay, and I see there are many subtypes with different filters... For example the SFH203PFA has an infrared filter. The -FA is black, the -P is transparent...
Would SFH203P work?
For example this one
http://www.ebay.com/itm/OSRAM-PHOTODIOD ... Swll1Wz~RK
and this other
http://www.ebay.com/itm/SFH203P-Fotodio ... SwRLZT63oK

have the same name but look different. I suppose the software is fine tuned for a particular type... This one looks transparent and is 200 km from my home! Would it work?
http://www.ebay.com/itm/SFH203P-Siliziu ... SwQItUKpAU


The other photodiode looks easier. Would this one work?
http://www.ebay.com/itm/1-Stk-BPW21R-/1 ... SwhAZWBvIL



By the way, I am curious to know what do each of them (the two photodiodes and the PIR) do in the circuit exactly...


Thanks a lot
Juan

[ThierryD]

Hi,

- PIR is not used, only the diffuser of the PIR
It costs less to buy a complete PIR only the only diffusor (ecxept if you find the same diffusor with a less cost, I doubt).
You buy a PIR only for use the plastic diffusor ...

-For the SFH203, if you see picture on my website SFH203 is transparent, not infrared.
Buy only a SFH203 transparent (all models is good).
SFH203 is use to detect lightning of the flash in Flash meter mode (for trigger the measure of the lightning)
This is OK : http://www.ebay.com/itm/SFH203P-Fotodio ... SwRLZT63oK
Do not use this because it is plate : http://www.ebay.com/itm/SFH203P-Siliziu ... SwQItUKpAU
Only rond and transparent.

- BPW21R is use to measure the light (in Light meter and in Flash meter)
It is important to use a BPW21R not a BPW21 (without R)n because BPW21R include a filter
(the glass is slightly green for cut infrared) because the calibration of the Light meter is with BPW21R and
because for measure visible light it is neccessary to cut infrared.


NB: for components (resistors, BPW21R, SFH203, capacitors, ....) if you cannot pass order on E44, you can use www.farnell.com
the shipping is 6.90 Euros.
Peaharps, if you order all your components on Farnell, you can cumulate only one shipping cost and peahaprs it is possible that all
components cost is lower than Ebay (component per component).
Except (Arduino, boost converter, FTDI who is less on ebay)


I hope to help your curiosity

Thanks for your help.
I have already ordered all the materials needed. Now just have to wait a few weeks !

Thanks also for the explanation about the photodiodes. Now it is clear... I was wondering how did you trigger the interrupt on arduino to measure the energy of the flash....
Can't be done everything with the BPW21?

Juan

[ThierryD]

Hi,
flash duration is in the interval 1/2000s to 1/20000s.
It is neccessary to separe trigger and measure because it is a very quick event.
If you trigger with BPW21R, you can measure after a few microseconds or even several tens of microseconds (for some internal Arduino reasons),
and lightning can during 50 uS (if flash is in low duration eg : 1/128 or 1/256).
It is not possible if you want measure the real energy of the lightning.

A+
ThierryD.

Hi again-
I've just started to build the flashmeter, as most of the components have already arrived.
I've stopped on R2, as you say 9.5MOhm, and all I have is 10MOhm. I assume it is not critical the value, and I might use 10MOhm instead of 9.5. In fact I have seen you say 10 Mohms in other parts of the explanation, but I would like to make sure...
May I use 10MOhn for R2?

Thanks again for and excellent project. I hope to be able to test it soon!

[ThierryD]

Hi,

I look at it tonight.
I'm at work and I need to consult the diagram but I'm pretty sure that the value of R2 does not matter: from 4.7 MB to 10 MB no problem.
I confirm that tonight.

Regards,
ThierryD.

[ThierryD]

Hi Zumix,
I confirm that you can put a 4.7 Mo to 15 Mo for R2, R2 is a pull up resistor.
Important resistor value is R1.

Regards,
ThierryD