grim_reaper
Senior Member
I'm thinking about a new project, which without going into detail, will require reading the state of around 40 reed switches. Usually I head straight for the 74HC165 (8 bit parallel in, serial out shift register), but I've noticed on several suppliers sites that they don't stock it any more.
I did a quick forum search and got this recent thread which references PCA9555 (16 bit I2C expanders) - I thought 'Yay! Newer technology!'.
Unfortunately, I don't have any experience with surface mount soldering (willing to try, but not at £4 a chip!) or designing boards for said system. 90% of my circuits reside on breadboards for years and only get assembled onto Veroboard when they are deemed reliable and I run out of breadboards!
So aside from the options of paying a larger amount for a break-out board with a PCA9555 on it, or getting 74HC165 chips from E-bay (with the associated risks), is there any kind of DIP chip anyone knows of that's as cheap as the 165? Preferably 16 bit and I2C like the PCA!
What other options are there for monitoring lots of individual digital inputs (aside from using 40X2s! - the reeds are in groups of between 6 and 15, so that would make wiring messy)?
I did a quick forum search and got this recent thread which references PCA9555 (16 bit I2C expanders) - I thought 'Yay! Newer technology!'.
Unfortunately, I don't have any experience with surface mount soldering (willing to try, but not at £4 a chip!) or designing boards for said system. 90% of my circuits reside on breadboards for years and only get assembled onto Veroboard when they are deemed reliable and I run out of breadboards!
So aside from the options of paying a larger amount for a break-out board with a PCA9555 on it, or getting 74HC165 chips from E-bay (with the associated risks), is there any kind of DIP chip anyone knows of that's as cheap as the 165? Preferably 16 bit and I2C like the PCA!
What other options are there for monitoring lots of individual digital inputs (aside from using 40X2s! - the reeds are in groups of between 6 and 15, so that would make wiring messy)?