badbiki
Junior Member level 2
16x16 map
This is an automotive related topic. Basicaly i have the following citcuit up and running. but for some strange reason, when its accessing the upper regions (colum 13,14,15,16) of the 16x16 matrix its having issues.. could be a circuit problem or an atmel micro issue.
The outputs from the 374 latch goto a port on an atmel processor, which constantly reads in the port, and sends it via serial.. where my software catches the bit stream, finds the start bit and displays where it is on a 16x16 matrix.. Very simple VB coding..
Can anyone outline any issues i may be encountering here? any chip selections i should make? HCT or HC series etc?
Assumptions
*200ns OE -> data output valid eprom times
*Map locations only read twice per rpm. motors reving to ~ 7,500rpm
*Atmel Serial BAUD rate @ 19,200
The 4-16 and 3-8 line decoders are used to select which region to look in for a given 256bit address range(16x16 matrix)... only ever one switch on each dil bank is selected at one time for one output from the 138 and 154..
This is an automotive related topic. Basicaly i have the following citcuit up and running. but for some strange reason, when its accessing the upper regions (colum 13,14,15,16) of the 16x16 matrix its having issues.. could be a circuit problem or an atmel micro issue.
The outputs from the 374 latch goto a port on an atmel processor, which constantly reads in the port, and sends it via serial.. where my software catches the bit stream, finds the start bit and displays where it is on a 16x16 matrix.. Very simple VB coding..
Can anyone outline any issues i may be encountering here? any chip selections i should make? HCT or HC series etc?
Assumptions
*200ns OE -> data output valid eprom times
*Map locations only read twice per rpm. motors reving to ~ 7,500rpm
*Atmel Serial BAUD rate @ 19,200
The 4-16 and 3-8 line decoders are used to select which region to look in for a given 256bit address range(16x16 matrix)... only ever one switch on each dil bank is selected at one time for one output from the 138 and 154..