0

Unknown Schematic values in bluetooth module example
Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.

Unknown Schematic values in bluetooth module example

by erich81 on Mon Jan 31, 2011 1:26 am

I was going to try and build a USB/Serial to bluetooth converter that would allow me to try and interface some hardware at work with my Android phone..after which I'm going to try and port one of our apps from winmo to android (it's all java based). I was looking at the example schematic provided by National, and had some questions regarding the resistors in it. they have values of "OR" and "NM". I've never seen this before, and after asking some of the engineers at work, they had no idea either.

Anyone know?
LMX9838Schematic.png
LMX9838Schematic.png (77.27 KiB) Viewed 1368 times

erich81
 
Posts: 35
Joined: Wed Jan 05, 2011 3:50 pm

Re: Unknown Schematic values in bluetooth module example

by ImaginaryAxis on Tue Feb 01, 2011 5:22 pm

Considering the schematic is using the rectangle symbol for a resistor, I am wagering that it is also using other European short hand.

NM - Not Mounted
0R - 0 Ohms

R is being substituted for the Omega symbol.

I have colleagues from Belgium that use 5kR for 5 kohms in their schematics.

Damn Europeans and their funny symbols. They drive stick-shift too.

ImaginaryAxis
 
Posts: 267
Joined: Sat Nov 13, 2010 3:16 pm
Location: Phoenix, AZ

Re: Unknown Schematic values in bluetooth module example

by dbc on Wed Feb 02, 2011 2:50 pm

Yup, L.A.W. has it right -- EU schematic conventions. It looks like the board is laid out so that you can get either TTL level or RS232 level signals based on a population option. "Zero ohm resistors" -- in other words, jumpers in an SMT package that are identical to the resistors that the board stuffing robot already handles -- are a common way of handling boards that can be populated N different ways to yield N different products.

dbc
 
Posts: 62
Joined: Thu Jan 06, 2011 7:37 pm
Location: Sunnyvale, CA

Please be positive and constructive with your questions and comments.