Thank you all =) For the past couple days we have been working on the user interface. This is the result do far: http://www.youtube.com/watch?v=NwBKmTFYuQk
The rotary encoder changes between the different measurements. As I add more features I can just add more cases to the loop, making it easy at the software. Bill: Vitaly wrote me a email offering some for sale. Lets see how this turns out. Otherwise I will go to ebay. Your link came back "Item 190675257 is no longer available." Do you remember the name of the seller? Jens: I am still studying how to approach other measurements, but I am happy with the results so far. I think I failed on explaining how I am doing it. Take a look at the INA219. It is the one I am using. For less than $3,00 I gave it a shot and it works quite nice. "The INA219 senses the small drop across the shunt for shunt voltage, and senses the voltage with respect to ground from VIN– for the bus voltage". It looks like the hobbyists are just starting to use it, or my google skills are quite modest, because I could not find anything better than the datasheet. Anyway I ended up drawing the component at eaglecad and writing the library for the arduino. I am trying some R and C measuring designs on the breadboard but nothing too promising so far. A box is on the way. At least is on the paper. http://tobiasmugge.files.wordpress.com/2012/06/nixieatmegav3.png http://tobiasmugge.files.wordpress.com/2012/06/nixieatmegav3_frontal.png http://tobiasmugge.files.wordpress.com/2012/06/nixieatmegav3_lateral.png Tobias On 1 jun, 04:42, jb-electronics <[email protected]> wrote: > Hello Tobias, > > nice project! I would very much like to see how this evolves. > > But just one thing: You mention you measure voltage before and after the > shunt to get a current reading. This sounds to me like you are wasting a > lot (!) of ADC resolution for that fact because you would always > subtract two voltages who are roughly of the same magnitude. > > Ever thought about an instrument amplifier (very sensitive differential > amplifier) across the shunt? You could also use some current sense ICs > who have all of these included (Linear Technologies has a lot of them). > > Jens > > > > > > > > > Hello, I am new to this group and I would like to introduce myself > > with a project that I have been working on. > > > This is my attempt to create a DMM using IN-12s, a IN-15A and a IN-15B > > as display. I used my nixie clock board as base, so it can double as a > > clock when not used as multimeter =) > > >http://tobiasmugge.files.wordpress.com/2012/05/dscn4039.jpg > >http://tobiasmugge.files.wordpress.com/2012/05/dscn4034.jpg > > > The uC is a Atmel Atmega328p. I downloaded arduino bootloader on it. > > I am using supertex HV5522 as drivers for the nixies. Two of them for > > 64bits. A friend of mine wrote a library for it that includes > > brightness control via the HV5522 blank pin. He is currently > > programming the clock while I work on the DMM. > > > Power consumption is around 3W. DC power supply from 9 to 12V. The > > voltage for the tubes is boosted from the input voltage using a switch- > > mode power supply based on the TubeHobby one. > > > The pictures and video shows voltage reading: is the only measurement > > I implemented on the software so far. Still thinking how to approach > > the scales/units. > > > I have a shunt resistor on the board and I plan on having voltage, > > current, power, frequency and duty cycle for DC. I am using a I2C A/D > > with a PGA, measuring voltage on both sides of the shunt. This was a > > fairly cheap solution, but the way I did it only works for DC and the > > range is 0 to 32V. But allows me to measure current and voltage at the > > same time =) > > > I have a video of the thing > > working:http://www.youtube.com/watch?v=PNYnFTeADow > > The maximum error I measured was 1,2% when comparing to my not-that- > > bad-multimeter. > > > I plan on implementing resistance, capacitance, inductance and AC > > voltage/current capabilities. Suggestions will be greatly appreciated! > > > The IN-15A showed on the pictures is not fully lightened. I am > > following Nick suggestion to burn it at 6mA for one hour. So far so > > good. > > > I am still trying to find some IN-12B as those include the dot. I do > > have 4 bits free on the HV5522 that I could use to drive IN-12B dots > > or INS-1. -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
