All Forums  GQ Electronics Forums  2.GQ Geiger Muller Counter  Using Geigerbot/Safecast-App with Iphone&GMC320

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Screensize: 640 x 480 800 x 600 1024 x 768 1280 x 1024 UserName: Password: Format Mode: Basic  Help  Prompt  Format: Font Andale Mono Arial Arial Black Book Antiqua Century Gothic Comic Sans MS Courier New Georgia Impact Lucida Console Script MT Bold Stencil Tahoma Times New Roman Trebuchet MS Verdana   Size 1 2 3 4 5 6   Color Black Red Yellow Pink Green Orange Purple Blue Beige Brown Teal Navy Maroon LimeGreen Message: * HTML is OFF * Forum Code is ON Smilies [quote][i]Originally posted by Nudnik[/i] [br]Finally I had some spare time to hook the GMC320 up with an Iphone 4s and find parameters for the safecast app. The first problem I encountered was the Iphone, not accepting audio input from the headphones mic in. I knew, this needs an extra resistor across mic in and ground for the iphone to switch the input path from built in mic to headphones mic. The internet suggested 1kohm. Guess what, I was out of 1k resistors so I tried a first shot with 680ohm but that didn't work. Then I tried 1.2kohm but that didn't work either. I then fiddled around with capacitors and serial resistors and what not, with no result. To make a long story short, after using a combination of 1.5kohm and 100kohm my Iphone finally decided to accept the 'headphone mic in' as audio input path. [img]uploaded/nudnik//schematics.jpg[/img][br] In app settings: Gamma sensitivity conversion factor: CO60: 39 (M4011 geiger bot default) Cs137: 33 (for 0.005 If you prefer 0.0065 set to 26) Offset CPM: 0 Not sure if I should set cpm offset to 12 due to tube noise (see datasheet)? Deadtime Correction: off RMS window: 1 Dead Time: 27 Sample Rate: 44.1kHz (max count: cpm = 60/(RMSxDT/SR) = 98.000cpm) Volume threshold: 10000 Input polarity: Both Input gain control: 0.90 These are preliminary parameters which seem to work. I will do further testing with different count rates and may come up with updated values. Regards Nudnik PS: sorry for my english. I'm not a native speaker. [/quote]    Insert an Image File Check here to include your profile signature.