# HG changeset patch # User Daniel O'Connor # Date 1384952205 -37800 # Node ID 8031548a5d48508863670bb848ff409d2cce8f4c # Parent e9efe3ddc9a7083479891ebd0e6aa56cff11efde Add some hardware notes. diff -r e9efe3ddc9a7 -r 8031548a5d48 hw/README --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/hw/README Wed Nov 20 23:26:45 2013 +1030 @@ -0,0 +1,23 @@ +The schematic is designed using TinyCAD +http://sourceforge.net/projects/tinycad/ + +The stripboard was laid out using VeeCAD +http://veecad.com/ + +It is loosly based on an Elektor circuit +http://www.elektor.com/magazines/2002/march/iec1107-electricity-meter-interface.55617.lynkx + +The photodiode is an OSRAM BP104, the IR LED a generic IR LED from Jaycar +(ZD1947) with a spectral peak of 940nm. The opamp is an LM348 clone (ZL3348 from Jaycar). + +The 6 pin interface is a TinyOS FTDI breakout +http://www.tinyosshop.com/index.php?route=product/product&product_id=186 + +Mine is running at 5V but it works at 3.3V. + +I needed to use the FTDI EEPROM tool to invert the TX & RX sense using FT_Prog from +http://www.ftdichip.com/Support/Utilities.htm + +The need to invert could be rectified by modifying the circuit, but modifying the +EEPROM was a lot easier than changing the circuit. +