see this Mastech M9803R

manual
http://web.cecs.pdx.edu/~jmorris/ECE241/ECE241%20Winter%202008/ECE241L%20Labs/Instrum%20Multimeter%20-%20Mastech%20M9803R%20Guide.pdf

shot from his box, with schematic
http://www.rapidonline.com/pdf/85-2295.pdf


you can buy from amzon
http://www.amazon.com/gp/product/B0007ZKESG/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=AMH4W1K8OCGMX#productDetails

review

(1) Lightweight
(2) Backlighted display
(3) Convenient form factor, and it has a fold out stand, which I find necessary.
(4) Compartments for either AA or 9V batteries are a nice touch, as is the hatch on top to stow the probes and cables.
(5) The display is clear and easy to read, although it provides limited visibility when viewed from above at an angle of perhaps 60 degrees (it offers sufficient lateral visibility).
(6) Carrying handle is, well, handy.
(7) Measures capacitance and frequency in addition to the usual suspects
(8.) Auto-ranging
(9) Faux analog meter
(10) RS-232 port/cable to link with computer (some serial-to-USB adapters may not work with this device; this is typically a driver issue)

On the minus side:

(1) Insubstantial (cheesy) and unusable probes. These could even be a safety hazard around high voltages. I had a professional set on hand that I am using with the M9803R.
(2) No marker on the FUNCTION/RANGE SELECTOR knob, so you can tell which setting it's pointing to. I corrected this by daubing a line of red model paint in the appropriate groove.
(3) The beep, for making continuity checks, for example, is not loud enough!
(4) Tiny little Philips screw to access the battery compartment
(5) No auto shutoff
(6) "Chinglish" Users Manual -- One of my faves: "The Continuity Measurement is always fixed the range." Hey, Honey. I fixed the range! When's supper?

also here it is the source code for the uart RS232 interface
http://sourceforge.net/projects/mmeter-read/



the price seems good, what do you think about ?

Fluke model 45

this is a very well documented multimeter, the RS232 protocol is pretty documented and explained, unfortunately this multimeter is very expensive and difficult to be found

thanks you guys, what do you think about "Lafayette DMB-1" ? I don't know Lafayette at all: is it a good product ?

the DMB-1 has the RS232 interface

Various models are easily found in Google

yes, searching "multimeter with RS232" is producing results from our friend "google", but ... how many of these results are providing "programming manual" or other details about the protocol used by the RS232 interface ?

they are used only to provide you a Windows software which has this knowledge while i need to write my own data logger system (on FreeBSD), so i need details about the protocol, or should i reverse it ?

yeppa, i am looking for a good multimeter equipped with a RS232 interface with a well documented protocol

True RMS, AC/DC voltage and current needed
nothing special else required, but it should be used remotely from the RS232

any item suggested ?
thanks =)

yeah, too hard life.

It was also difficult to get the fpga soldered at a reasonable price, the only fpga chip costs $40, while getting the chip soldered on the breakout-board costs $90 (a bit expensive, don't you think ?).

really a too hard life for a student  

btw, i have been knocking at the ST's doors explaining them my problem and asking them for a free sample as they are producing an equivalent chip to the Maxim's one. To be honest i prefer the Maxim's one: if the ST''s guys will say "no way", i think i will try to get money to go to buy the part from Mouser. This will take me a lot of time, so i will probably miss the exam's practical laboratury. That's life.

However, that does not mean that you have any right to expect to receive components just for furthering your own hobby or indeed your own education.

No right at all, i am not pretending nothing from them, just wandering why in the past (early 2000 years) it was possible and now it is not. My brother got his university degree in 2005 and it was 20% supported by Maxim in his university project, i have payed the 90% of the components of my project and now i only need a chip from Maxim, a chip that is very difficult to obtain with a reduced price if you pick up an order as private individual: 30 euro of difference, for example.

You can't use Yahoo or Gmail addresses but, you do not have to use a corporate address either.

the first time i used @gmail.com, the second time i used @polimi.it, that is my student email domain

I don't know if you are using a public computer but, if your not, you should have an address that your internet provider will give you access to.

i am not using a public computer, i am using my ADSL, my provider is Telecom and they only provide me ADSL flat service with a dynamic IP, no email with their @telecom.it domain

In the information portion of their forms, I made it clear I was a hobbyist and my plans for a product are well into the future.

i did too, when they asked "which company are you ?" i have filled the name of my university, also i filled "university project" in the field where they ware asking "which use is this chip for ?"

but no way: could i ask which domain @xxxx??? have you used ?

You want a part? go buy the part!

Well, this is an university project which i am running in as hobby in my free time, i am considering it "hobby" because it is a complementary part of an university exam: it is not required in oder to pass the exam, but it could be a good opportunity to translate theory into something of practical, anyway it is very appreciated as learning experience. I bought an fpga of 100 euro, other analog parts for other 110 euro, for a total of  210 euro (which are a lot of money for a student), now i need a nvram at 512Kb/3.3V in DIP package (i have no skill and no money to buy the tools required for SOIC or other smd stuff) and an other little chip which is terrible difficult/expensive for me to find and buy from resellers.

I am wondering if to switch from Maxim (bye bye Maxim) to an other chip vendor: for example ST for the zeroram parts and Analog Devices for the analog sample i need.

Hi,
When try to request samples i got this message:

Order Denial
Please note that public domain e-mail addresses (e.g. @yahoo.com, @gmail.com, etc.) are not supported with free samples.
If you are using a public domain e-mail address, please logout and re-login with a business or educational e-mail address.

Sorry, but we are unable to process sample requests from non-business or non-educational e-mail addresses via this site.

Your options are:
Click here to purchase parts.
Resubmit your request using a business or educational e-mail address registered with Maxim.
Contact your local Maxim distributor.

does maxim stop to give out sample, or it block the free e-mail now ?

As did the login with my personal @gmail.com mail I asked for samples again
but this time i did the login with my educational e-mail address.
My university has provided me an email account ending with @their.domain

but still no way ='(

Sorry, but we are unable to process sample requests from non-business or non-educational e-mail addresses via this site.

This let me suppose to be happening because guys have misused Maxim's service, putting different addresses and names and ordering quite a lot of components by putting >1000s of pieces as their project requirement, so Maxim were sending samples straight away with high expectations on a bigger order in near future, but later they have realised that it is just a fraud: no mass quantity orders by individuals.

I think It should be really okay to order one or two free samples for experiments by people like students which aim to realize a circuit which needs a pair of Maxim's components, also it could be fine for them: students are are the people who will join the industry one day, so they will introduce the good products that they have been experimenting throughout the past for bigger projects.

That means a real big order of a real quantity of >1000 of Maxmim chips, placed from a real Company. So I think they should clearly identified this and they should make that restriction without blacklisting the whole country and universities.

Anyway, the domain of my university seems banned ='(

Yes it's an iPad App, i did a mistake, so it's perfect for my iPad mini! Thanks.

@robtillaart

It's the 70% of what i am looking for. It uses the on screen keyboard while i'd like to use the pencil, also it's OK only for Android Tablet while i have an iPad tablet on my hands. BTW it's OK to satisfy my goal: it allows you to add notes to pdf, so, if i will find nothing similar for iPad it may be i will get this Android's App running on a new Nexus tablet for xmas =P

@dhenry
I need something like this App for my university

Thanks =)

Hi
i am looking for an iPad App which makes me able to read a pdf document, adding my page notes, as naturally as you could imagine to write notes on the screen with capacitive pencil over the capacitive glass of the tablet. I know they sell such a special pen that males you able to write on the screen, i am looking for that App.

Any iPad App ? If no, is there something similar for Android ? If so, which Android Tablet do you suggest ?

hi
i need to realize a pyQt application (App.py) that means using python as programming language and QtOpenGL as framework.
My problem is to put all this software on macOSX 10.7, i got a lot of issues about running QtOpenGL.

i am using mac-ports, i have installed a lot of things, OpenGL should be installed by default in MacOSX-10.7.5, but running my App.py i got this

Traceback (most recent call last):
  File "cal_gui.py", line 3, in <module>
    from ui_cal import Ui_Cal
  File "ui_cal.py", line 483, in <module>
    from pyqtgraph.opengl import GLViewWidget
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pyqtgraph/opengl/__init__.py", line 1, in <module>
    from .GLViewWidget import GLViewWidget
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pyqtgraph/opengl/GLViewWidget.py", line 1, in <module>
    from pyqtgraph.Qt import QtCore, QtGui, QtOpenGL
ImportError: cannot import name QtOpenGL

pyQtOpenGL has been installed as python wrapper to QtOpenGL

Anybody toying with this on mac ? On linux it is pretty working but i need to put it on mac.