FrequencyTimer2 arduino Mega

Forum 2005-2010 (read only) Hardware Interfacing
1

I have been trying to interface an HDPM01 combination pressure/compass sensor. The datasheet section on the pressure sensor is largely the same as the HP03 and so I have been trying to use Michael Margolis' HP03 library which calls FrequencyTimer2. I have an Arduino Mega and I found this posting about using FT2 with that board.
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1239820770/15
and using those tips I got it to compile.

there is a comment in HP03 that FT2 is hard coded to pin 11. I recall that the pin/port correspondence is not constant, see:
http://spreadsheets.google.com/pub?key=rtHw_R6eVL140KS9_G8GPkA&gid=0

worse, it seems like the pin 11 is timer 1 on one and timer2 on the other.

I think this clarifies what was going wrong in the earlier forum discussion I cited, but leaves me needing to know a LOT more about the arduino timers than I do. It looks like FT2 is unlikely to work on the Mega unless someone has built a newer version than I have found.

2

Digging into this a little more, FT2 is written in PORT commands, pin 11 on the 168 is PB3. so whatever corresponds to PB3 on the mega is actually what's being manipulated in FT2. That is pin 50 on the mega, which (at least in the spreadsheet) is not listed as having a timer associated with it.
Worse and worse.

3

I think the answer, in general, may be the Tone() library which I have not used. That seems to be able to produce square wave output at up to 32k hz. It is written so that all of the Arduino boards are supported.

I can produce a 32K hz square wave from a DS1307 and so I will not need Tone at this time, I think.