ZBasic Forum

I have a project based around a ZX24a which is performing the main tasks, however i need to decode a 38khz IR signal and was wondering about using a native mode chip to decode the signal and simple signal the zx24a when the correct signal is received.

Never having using native mode before I have a couple of questions:-

do i need some interface h/w to download to something like a zx-328n

is the pin out of 328 by and wild chance the same as the parallax sx range of chips (now discontinued) - if so i can use the dev board i have

Is the 328 the right choice for this front end task given i don't have surface mount skills ?

thanks

Your append has several different points in it. In terms of native mode devices, there is more available than just the 328n. There is also the 24-pin ZX-24n and 40-pin ZX-24nu. The ZX-24n is probably most compatible with a 24-pin Stamp.

In terms of the mega328 there are several different versions including a barebones 28-pin DIP (328n) and a 28-pin module called the ZX-328nu - neither of these devices require any SMD soldering.

I was considering the 328n because of cost mainly I guess. If I go down the zx24n route then I get more speed (over zx24a) but same cost as zx24a or thereabouts.

In terms of pins i only need a couple so no need to consider the bigger devices in this case.

thanks for your input

FFMan wrote:is the pin out of 328 by and wild chance the same as the parallax sx range of chips (now discontinued)

Not at all. I suppose that you could hand-wire an adapter board of some sort if you wanted to take advantage of I/O on the dev board. You'd need to put the crystal and serial interface circuitry on the adapter and route only the I/O pins to the dev board.

FFMan wrote:I was considering the 328n because of cost mainly I guess.

dkinzer wrote:...you could hand-wire an adapter board of some sort if you wanted to take advantage of I/O on the dev board. You'd need to put the crystal and serial interface circuitry on the adapter and route only the I/O pins to the dev board.

Cost is a relative term. As Don says you also need the associated circuitry and a serial port interface. If you only have USB then you also need a USB to RS232 adapter - it all adds up.

Or you get get a ZX-328nu which integrates everything and is cheaper than the ZX-24n or ZX-24nu. It may also fit into your Stamp board as the "top" 24 pins are similar with Digital I/O on one side and ADC/Digital on the other. The only difference is that pins 1-3 carry TTL signals rather than RS232 levels but then again you do have USB onboard. The only real compatibility issue is a physical one - is there enough room for a 28 pin 600 mil device in the 24-pin socket? A few female headers may be all you need to raise the height of the ZX-328nu PCB.

Is there a circuit diagram available somewhere of a basic zx24n setup to get me started ?

thanks

FFMan wrote:Is there a circuit diagram available somewhere of a basic zx24n setup to get me started ?

I'm not sure why you have posted this twice in 2 different threads. Perhaps you can delete the other post.

The pinout for the ZX-24n is the same as the ZX-24a. If you meant a ZX-328n circuit diagram (instead of ZX-24n) then the need to look at appendix G of the documentation.

posted twice becuase my fingers got in a muddle - other psot now deleted.

yes sorry i meant 328 - busy day here at the factory

thanks for the pointer to appendix g - now if only i didn't have to wait a month for stuff to get to the UK !