| ??? 02/19/08 20:32 Read: times |
#151165 - lots of i/o |
Hello Forum
I got a task to do some test equipment. This device will of course be 8051 powered, and need some 32 inputs and 32 outputs. I will then have 32 pins, wich can be read - input - and written - output. Something like the inside of of a std. 8051 i/o pin, but with aditional components for protecting the pins against the nasty outside world. I dont want lots of '573 devices - to manny wires, to much buscapacitance etc. I did considder using PCF8574 and PCF8574A on a i2c bus. I does however take up a lot of PCB realestate. I thought about using small 8051 as slave devices. A P89LPC935 in a nice PLCC28 package will give me 8 inputs and 8 outputs for aprox 2 USD - or the same as a asingle PCF8574. I'll gues I could tie 8 slaves together on a rx/tx bus, using wired or, and have the master control the party. Any comments greatly apreaciated! Per |
| Topic | Author | Date |
| lots of i/o | 01/01/70 00:00 | |
| There are 16-bit Expanders | 01/01/70 00:00 | |
| The + and - of the slave processor | 01/01/70 00:00 | |
| the logical solution is to ... | 01/01/70 00:00 | |
| Roll 'yer own, and get exactly what you want | 01/01/70 00:00 | |
| why bother | 01/01/70 00:00 | |
| you're right, if "conventional" I/O ports are OK | 01/01/70 00:00 | |
| Max 7301 | 01/01/70 00:00 | |
| lots of i/o part 2 | 01/01/70 00:00 | |
| Theres a 40way NXP I/O expander | 01/01/70 00:00 | |
| Simple Distributed Concept | 01/01/70 00:00 | |
| very valid point | 01/01/70 00:00 | |
| For sure.....the multi-port job.... | 01/01/70 00:00 | |
| lots of i/o part 3 | 01/01/70 00:00 | |
| I love slave processors | 01/01/70 00:00 | |
MCP23008 | 01/01/70 00:00 |