Why not use a I2C extender such as the PCF8574 (8 bit) or the PCA9535 (16 bit). Since we already have I2C read and write routines for the Si570, this would require 0 additional lines. The extenders have three address lines which set their address. As long as each device has a different address, there is no problem.
Dave - WB6DHW <http://wb6dhw.com> On 2/26/2014 11:08 AM, Dan Reynolds wrote:
Never mind my questions. I figured out how the 4017 works. In mine I think I will use a 74HC595. It uses three lines from the Arduino but can have multiple output lines high and I was thinking of switching the "other" LPF's with it as well.Again, I'm learning a whole lot by following along in all these discussions. A whole lot!! And I think that's a good thing. I really like that you're bring the Arduino and the ham world together in this project.73 Dan -- KB9JLO https://sites.google.com/site/on30ng/On Tue, Feb 25, 2014 at 10:59 AM, Dan Reynolds <on30ng@xxxxxxxxx <mailto:on30ng@xxxxxxxxx>> wrote:When will the radiono code have the bandswitching for this design in it? I'm not pushing just more curious about what the code will look like. Are you still using the original bandswitching code & hardware for the (2) receiver LPF's? Or were you planning to run them also off the CD4017 here? Thanks Farhan. I'm learning a lot by following along in this process. At some point though I think I need to build something! Hi, hi! :-) 73 Dan -- KB9JLO https://sites.google.com/site/on30ng/ On 23/02/2014 6:34 AM, Ashhar Farhan wrote:I just finished a linear amp that is entirely RC-coupled except for the power stage's output. I have built two of them and they appear to very quite stable and clean. It uses just the 2N3904s in the chain except for the power output stage. The details are here http://www.hfsignals.org/index.php/RF386 It started with the a stupid question "Why can't the LM386 be used in an RF linear?" I am particulary curious to know what value should one pick for the 100 ohms in the Q4. I am quite kicked by the one-line band-switching arrangement. - farhan
