sleep w memory rentention problem

[mr_creosote]

hi,

i'm not able to have the nRF24LE1 go to sleep. I'm using the example at the link below, to which I've added code for UART and ADC usage. Is there a way to end the UART (the opposite of the hal_uart_init() function)?

I need the LE1 to wake up, take an analog reading, write it to the UART, then go to sleep for x seconds. I'd like it to sleep for 10 seconds but it seems 2 is the maximum I can get with this MUP.

code example:

www.nordicsemi.com/.../How-to-setup-memory-retention-timers-on-on-the-nRF24LE1

In the example, what do these lines do?

IEN1 = 0x20; EA = 1;

// Go to standby mode and wait for RTC interrupt

PWRDWN = 0x07; // Clear power down

PWRDWN = 0x00;

Thanks!

Mahesh

[mr_creosote]

Hi, I'm not able to get the sample code working -- the entire file from your website is listed at the very end. What am I missing? i have some questions about the code:

In the function mcu_init():

---------------------------

1. what is it's purpose?
2. there is a comment "XOSC32K input". Is there anything in THIS function that has to do with the clock?
3. for the 32-pin nRF24LE1 package, can setting P2DIR, P3DIR, P2 and P3 be skipped?
4. does OPMCON = 0x00 just keep the pin directions PxDIR in memory during sleep?

the function wakeup_tick():

---------------------------

1. is it an ISR? 
2. is it executed only on wake up from the tick? 
3. do interrupts need to be disabled before doing any work in this? 

the function main():

--------------------

1. does mcu_init() need to be the first thing that's called?
2. is the code within the else {...} executed ONLY ONCE, upon startup, i.e. wake up is not from tick?
3. is the code within if(PWRDWN & 0x40) {...} executed during the 2nd and all subsequent invocations of main()?
4. what happens when PWRDWN is set to 0x00? bits 2:0 are b000. table 60, page 113 of the prod spec v1.16 does not specify what this means. it reads "Set system to power down if different from 000."

general question:

------------------

should WUCON be used at all?

SAMPLE CODE BELOW:

------------------------

from: www.nordicsemi.com/.../How-to-setup-memory-retention-timers-on-on-the-nRF24LE1

/*

* An nRF24LE1 MEMORY RETENTION TIMER ON example application 

*/

#include <Nordic\reg24le1.h>

#include <stdint.h>

#include "hal_clk.h"

#include "hal_rtc.h"

uint8_t xdata toggle;

void mcu_init(void)

{

// XOSC32K input

P0DIR = 0x03;

P1DIR = 0x00;

P2DIR = 0x00;

P3DIR = 0x00;

P0 = 0x00;

P1 = 0x00;

P2 = 0x00;

P3 = 0x00;

// Open latch 

OPMCON = 0x00; 

}

void wakeup_tick() interrupt INTERRUPT_TICK

{

// Toggle output on wakeup

P02 = toggle;

toggle = !toggle;

}

void main(void)

{

mcu_init();

// If wakeup from tick, turn on LED

if(PWRDWN & 0x40)

{

IEN1 = 0x20;

EA = 1; 

// Go to standby mode and wait for RTC interrupt

PWRDWN = 0x07;

// Clear power down

PWRDWN = 0x00;

} 

else

{

// Init RTC timer

hal_rtc_start(false);

hal_clklf_set_source(HAL_CLKLF_XOSC32K); 

hal_rtc_set_compare_mode(HAL_RTC_COMPARE_MODE_0);

hal_rtc_set_compare_value(0x7FFF);

hal_rtc_start(true); 

}

// Lock latch

OPMCON |= 0x02;

// Memory retention mode timer on, system reset on wakeup

PWRDWN = 0x03; 

while(1);

}