Skip to main content

Current draw of a D1 Mini in deep sleep

To measure the deep sleep current draw of the D1 Mini, I hooked up 4 NiMH AA batteries in series (~5.2V) to its 5V and GND pins.

The sketch uploaded to the D1 Mini was a nominal:

void setup() {
  ESP.deepSleep(60)*60*1000000UL, WAKE_RF_DEFAULT);
}

void loop() {
}

The current draw was a pretty steady 0.8mA, or 800uA. That's a obviously a far cry from the sub-100uA reportedly achievable with the barebones ESP-01 due to all the extra components on the D1 Mini.

Reported deep sleep current draw for the D1 Mini is all over the place, from 0.21mA (5V), to 0.3mA (3.3V), to 6mA (USB)!

Notes:

1. Connecting a 18650 battery (~4V) to the 5V pin did not work. In theory, the MC6211 LDO used by the D1 Mini means anything higher than 3.56V should work. But when connected, the onboard LED started to flash in a slow but erratic fashion, I suspect it is randomly resetting (because each time the D1 Mini powers up, the onboard LED flashes briefly).

2. Connecting a 18650 battery to the 3.3V pin did work, though in theory it shouldn't be done because the 3.3V is not connected to any voltage regulator. So the 4V goes directly to the ESP8266, which has a theoretical upper limit of 3.6V. But it did work for me (others have reportedly connected up to 5V to the ESP8266 with no problems, but don't push your luck!), and the deep sleep current draw was ~1.5mA. I suspect if I could hook up a regulated 3.3V source to the pin, the deep sleep current draw should fall closer to the 0.8mA range.

3. Connecting 2 x alkaline AA (3.2V) to the 3.3V pin did not work. The onboard LED started to flash erratically again. In theory, this should work, since the ESP8266 has a minimum operating voltage of 2.5V, but there have been many reports of the chip being finicky with the input voltage, so who knows.

Comments

Popular posts from this blog

Adding "Stereo Mixer" to Windows 7 with Conexant sound card

This procedure worked for my laptop (Thinkpad E530) with a Conexant 20671 sound card, but I suspect it will work for other sound cards in the Conexant family. I was playing with CamStudio to do a video capture of a Flash-based cartoon so that I can put it on the WDTV media player and play it on the big screen in the living room for my kids. The video capture worked brilliantly, but to do a sound capture, I needed to do some hacking. Apparently, there was this recording device called "Stereo Mixer" that was pretty standard in the Windows XP days. This allowed you to capture whatever was played to the speaker in all its digital glory. Then under pressure from various organizations on the dark side of the force, Microsoft and soundcard makers starting disabling this wonderful feature from Windows Vista onwards. So after much Googling around, I found out that for most sound cards, the hardware feature is still there, just not enabled on the software side. Unfortunately, to

Attiny85 timer programming using Timer1

This Arduino sketch uses Timer1 to drive the LED blinker: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 /* * Program ATTiny85 to blink LED connected to PB1 at 1s interval. * Assumes ATTiny85 is running at 1MHz internal clock speed. */ #include <avr/io.h> #include <avr/wdt.h> #include <avr/sleep.h> #include <avr/interrupt.h> bool timer1 = false , led = true ; // Interrupt service routine for timer1 ISR(TIMER1_COMPA_vect) { timer1 = true ; } void setup() { // Setup output pins pinMode( 1 , OUTPUT); digitalWrite( 1 , led); set_sleep_mode(SLEEP_MODE_IDLE); // Setup timer1 to interrupt every second TCCR1 = 0 ; // Stop timer TCNT1 = 0 ; // Zero timer GTCCR = _BV(PSR1); // Reset prescaler OCR1A = 243 ; // T = prescaler / 1MHz = 0.004096s; OCR1A = (1s/T) - 1 = 243 OCR1C = 243 ; // Set to same value to reset timer1 to

Hacking an analog clock to sync with NTP - Part 5

This is how it looks after I have put everything together. The Arduino sketch is available here . The 2 jumper wires soldered to the clock mechanism are connected to pins D0 and D1 on the ESP-12 (in any order). When the device first boots up, it presents an access point which can be connected to via the PC or smartphone. Once connected, the captive portal redirects the web browser to the configuration page:     A custom field has been added to the WiFi configuration page to enter the current clock time in HHMMSS format. Try to set the clock time to as close to the current time as possible using the radial dial at the back of the clock so the clock will have less work to do catching up. In the config page, the HTML5 Geolocation API is also used to obtain your current location (so if your web browser asks if you would like to share your location, answer "yes"). This is then passed to the Google Time Zone API to obtain the time and DST offset of your time z