n740.c File Reference

This file provides functions to control various chips on the Sensinode N740s: More...

#include "dev/n740.h"
#include "dev/uart1.h"

Go to the source code of this file.

---

Detailed Description

This file provides functions to control various chips on the Sensinode N740s:

• The 74HC595D is an 8-bit serial in-parallel out shift register. LEDs are connected to this chip. It also serves other functions such as enabling/disabling the Accelerometer (see n740.h).
• The 74HC4053D is a triple, 2-channel analog mux/de-mux. It switches I/O between the USB and the D-Connector. It also controls P0_0 input source (Light Sensor / External I/O)

Mux/De-mux: Connected to P0_3 (set to output in models.c Changing the state of the mux/demux can have catastrophic (tm) results on our software. If we are not careful, we risk entering a state where UART1 RX interrupts are being generated non-stop. Only change its state via the function in this file.

Shift Register: For the shift register we can:

• write a new instruction
• remember and retrieve the last instruction sent

The chip is connected to CPU pins as follows:

• P0_2: Serial Data Input
• P1_3: Shift Register Clock Input
• P1_1: Storage Register Clock

This file can be placed in any bank.

Author:

George Oikonomou - <oikonomou@users.sourceforge.net>

Definition in file n740.c.