Changes between Version 3 and Version 4 of Prototype/Two

Timestamp:

07/05/10 19:36:33 (14 years ago)

Author:

art

Comment:

--

Prototype/Two

@@ -1 +1 @@
 = Second Prototype (SMD version) =
 
+== Prepare ==
 Finally I spend around one month (only my free time) to prepare a layout design with EAGLE for my second prototype. This time it is all based on SMD components and should be pretty small. The problem now is to find a good company which could etch the board for me. I finally stopped at [http://www.pcb-pool.de PCB-Pool.de] which did the work really good. I had to order there a 1dm^2^  board, so that I got second kit for free. For the etching process, I payed around 50.- Euros. For all the components used on the board, I payed again around 80.- Euros. However I had to order the components of the board in big packages. I've received all of them from [http://de.rs-online.com/web/ RS-Online.de]. If I compute the final material price for one such kit, then we will end up in around 60-70.- Euros, just for the material, which is still ok for a prototype. 
 
@@ -6 +7 @@
 
 [[Image(http://www.tevs.eu/stuff/pcb.png, 400px)]]
+[[Image(http://www.tevs.eu/stuff/bmw/IMAG0030.small.jpg, 220px)]]
 
+Finally after one week the PCBs arrived and I was surprised about the quality. Unfortunately my camera was not available at this time, hence I had to make pictures with my cell-phone :(
+
+== Build ==
+After several weekends of soldering (have I told already that I am working only on weekends on this project), I build the prototype into the housing. Now I am using 14MHz crystal to drive the ATmega. Additionally I am using [http://www.nxp.com/documents/data_sheet/PCF8574.pdf PCF8574] port expanders to ask for button and rotary encoders state. This helps me also to reduce wirings and to make everything more suitable for this small housing.
+
+[[Image(http://www.tevs.eu/stuff/bmw/IMAG0032.jpg, 630px)]]