CCS C Software and Maintenance Offers
FAQFAQ   FAQForum Help   FAQOfficial CCS Support   SearchSearch  RegisterRegister 

ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

CCS does not monitor this forum on a regular basis.

Please do not post bug reports on this forum. Send them to CCS Technical Support
Sleep Currents

 
Post new topic   Reply to topic    CCS Forum Index -> General CCS C Discussion
View previous topic :: View next topic  
Author Message
Gabriel



Joined: 03 Aug 2009
Posts: 1080
Location: Panama

View user's profile Send private message

Sleep Currents
PostPosted: Sat Jun 27, 2026 9:43 am     Reply with quote
Hi all,

Im developing a Temperature LORA sensor.
I have a custom board with a PIC18F47Q84, EEPROM, and RTC to wake up via EXT INT.
The board is powered by 3x 18650s (paralleled) through a MCP1700 LDO.
Im using the RYLR896 radio and BME280 as the sensor.

I cant get sleep Current under 0.100mA which is absurd - or maybe i hit my boards limit? i refuse to belive this, and battery life obviously sucks when i have such a large bank.

Edit: also ive taken care of checking every pull up on the board, to ensure none are kept low during sleep, this was happening with botht the RTCs interrupt pins... huge current gains obviously.

Edit_2: fuses

Code:
#include <18F47Q84.h>
#device PASS_STRINGS=IN_RAM
#device adc=8
#fuses MCLR
#fuses NOWDT
#fuses NOLVP
#fuses NOXINST
#fuses NODEBUG
#fuses NOBROWNOUT
#fuses NOLPBOR
#fuses NOPROTECT
#fuses HS
#fuses RSTOSC_EXT_PLL
#use delay(clock=64MHz)


CODE:


Code:

disable_interrupts(INT_RDA);
                sleep(SLEEP_FULL|REG_LOW_POWER);
                delay_ms(2);
                setup_oscillator(OSC_EXTOSC_PLL|OSC_CLK_DIV_BY_1|OSC_PLL_ENABLED|OSC_EXTOSC_READY);
                delay_ms(1);


this is my sleep "method".

ive taken particular care to disable everything i can think of. i even have a function called "Disable_Everthing();"
PIN BY PIN!


Code:

void Disable_Everything()
{
    setup_wdt(WDT_OFF);
    setup_ccp1(CCP_OFF);
    setup_ccp2(CCP_OFF);
    setup_ccp3(CCP_OFF);
    setup_counters(RTCC_OFF,RTCC_DIV_1);
    setup_timer_0(T0_OFF);
    setup_timer_1(T1_DISABLED);
    setup_timer_2(T2_DISABLED,0,0);
    setup_timer_3(T3_DISABLED);
    setup_timer_4(T4_DISABLED,0,0);
    setup_timer_5(T5_DISABLED);
    setup_timer_6(T6_DISABLED,0,0);
    setup_pwm1(PWM_DISABLED);
    setup_pwm2(PWM_DISABLED);
    setup_pwm3(PWM_DISABLED);
    setup_pwm4(PWM_DISABLED);
    setup_spi(SPI_DISABLED);
   
    setup_clc1(CLC_DISABLED);
    setup_clc2(CLC_DISABLED);
    setup_clc3(CLC_DISABLED);
    setup_clc4(CLC_DISABLED);
    setup_clc5(CLC_DISABLED);
    setup_clc6(CLC_DISABLED);
    setup_clc7(CLC_DISABLED);
    setup_clc8(CLC_DISABLED);
   
    setup_smt1(SMT_DISABLED);
    setup_smt2(SMT_DISABLED);
   
    setup_dsm(DSM_DISABLED);
   
           
#ifdef VERSION_1
    input(BAT_SENS); //A0
#endif
   
#ifdef VERSION_2
    setup_comparator(NC_NC_NC_NC);
    setup_vref(VREF_OFF);
    setup_dac(DAC_OFF);
    output_low(PIN_A2);
#endif   
   
  //output_low(PIN_A0);  //LECTURA DE BAT
    output_low(PIN_A1);
  //output_low(PIN_A2);  //OFF EN V.2 y INPUT en V.1
    output_low(PIN_A3);
    output_low(PIN_A4);
    output_low(PIN_A5);
   
  //output_low(PIN_B0);  //INTERRUPT
  //output_low(PIN_B1);  //INTERRUPT
    output_low(PIN_B2);
   output_high(PIN_B3);  //LORA RESET
  //output_low(PIN_B4);  //LORA UART
  //output_low(PIN_B5);  //LORA UART
    output_low(PIN_B6);
    output_low(PIN_B7);
 
    output_low(PIN_C0);  //FTDI   
    output_low(PIN_C1);  //FTDI 
    output_low(PIN_C2);
  //output_low(PIN_C3);  //I2C 
  //output_low(PIN_C4);  //I2C   
    output_low(PIN_C5);
    output_low(PIN_C6);
    output_low(PIN_C7);
   
   
    output_low(PIN_D0);
    output_low(PIN_D1);
   
#ifndef USE_DS
    output_low(PIN_D2);
    output_low(PIN_D3);
#endif
    output_low(PIN_D4);
    output_low(PIN_D5);
    output_low(PIN_D6);
    output_low(PIN_D7);
   
    output_low(BAT_SENS_ENABLE); //E0/enable in V.1
    output_low(PIN_E1);
    output_low(PIN_E2); 
}


im on my second revision of the board, the previous used an opamp and internal DAC to check the 18650 voltage indirectly... that was costing me about 0.400mA! - thats gone now - i managed to get that board revision down to 0.250mA.

still crazy sleep currents.

what am i missing? getting down to 0.050mA would be a huge win a this point.

thanks,
G
Code:

_________________
CCS PCM 5.078 & CCS PCH 5.093
Ttelmah



Joined: 11 Mar 2010
Posts: 20096

View user's profile Send private message

PostPosted: Sat Jun 27, 2026 11:11 am     Reply with quote
What commands are you sending to the LoRa module to put it to sleep????
If it is staying awake, it'd explain a lot of this. You need to send the
sleep command to the module.
Also the MCP1700, is a low power regulator, but is a linear regulator. So
will waste you quite a lot of power.
Also you don't show how you are programming the BME. If it is left in
continuous sample mode, as opposed to being put back into sleep mode
it'll draw a lot more current.
How is the PIC being woken up?. What interrupt are you using?.
Remember interrupts need to be cleared before you sleep, or the chip
won't sleep but will awake immediately.
Gabriel



Joined: 03 Aug 2009
Posts: 1080
Location: Panama

View user's profile Send private message

PostPosted: Sat Jun 27, 2026 12:05 pm     Reply with quote
hi Ttelmah!

for the lora im just using the AT command sleep:
Code:
fprintf(LORA,"AT+MODE=%u\r\n",LORA_SLEEP);


LORA_SLEEP is defined as 1 - mode 1 is sleep.

im using EXT and EXT1 to wake up.
for context: the RTC has a Minute alarm, and a seconds alarm.
I wake up every minute, go back to sleep for random amount of seconds, and then transmit... as a transmission overlap avoidance method (i have multiple of these sensors laying around).

ext1 on the minute alarm, ext on the seconds.


for the BME its in single shot mode - however i have this code setup to work with S17021, DS18B20, and BME280 (i like having choices) - same issue across the sensor line - witht the DS18B20 i even go as far a removing power with a dedicated pin - same issue.

I am NOT clearing the interrupts, thank you for that.
i will test and report!

thank you!
G
_________________
CCS PCM 5.078 & CCS PCH 5.093
Display posts from previous:   
Post new topic   Reply to topic    CCS Forum Index -> General CCS C Discussion All times are GMT - 6 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group