ESP8266 connecting to the network after ESP.deepSleepInstant() command

Question

Hi. Looking to get my module working on batteries, I decided to use the espNow functionality and deepSleep. And now I'm experimenting with different ways of putting the microcontroller to sleep, it turns out that probably the least current-consuming mode is It allows the maximum reduction of...

khoam · Accepted Answer

. Does this mean that esp_now_init() returns a code different from zero? ESP.deepSleepInstant() causes the chip to fall asleep immediately, without waiting for WiFi to turn off, as ESP.deepSleep() does. Try calling WiFi.mode(WIFI_SHUTDOWN) before calling deepSleepInstant().

khoam · Accepted Answer

. As a quick note, you can change this delay(100) to e.g. delay(10) and check that it initialises correctly. This is in the Adafruit_BME280.cpp library file, around line 135. . There is no I2C hardware controller on the ESP8266, so that 400 kHz is a pipe dream .

khoam · Accepted Answer

I looked at another library for the BME280 (Sparkfun: Link ). No such tricks with delay() there either.

Zubiik · Answer

I haven't actually checked this. You are a master regardless of whether I call ESP.deepSleepInstant() or ESP.deepSleep(); ESP resumes transmitting after sleep. Another mAh saved. The last bottleneck in my application is the BME280 which initialises in about 100ms. Anyway, now from waking up by reading the BME and sending it via esp_now (great stuff by the way, and I've seen practically no examples with this protocol on the Polish web) it takes 300ms with the biggest current draw of 60mA taking only 100ms. HUGE thanks! .

khoam · Answer

. All in all, I'm not surprised. Imagine that in the code of the Adafruit_BME280::init() function, a delay(100) command is inserted at the very end. I have no idea why . Code: C / C++Log in, to see the code . You could try an alternative library for the BME280 and ESP8266: Link . It's a bit 'old', but uses the original Bosch code.

Zubiik · Answer

. And it's a shambles :/ interestingly I tried to get around this delay because from the waveforms it seemed that after 15ms the BME was ready to work i.e. the last frame was sent to it after that time. However, trying to read earlier than the begin() function finished was not giving correct results. I don't want to duplicate posts because I also asked about solving this problem on forbot. There I described in more detail what and how And so I thought there must be something wrong with this lib from Adafruit because it's impossible that such a chip takes so long to start.

Zubiik · Answer

That's how I was combining it too. The problem is that a while ago I messed up the last ESP that receives data and sends to the server, I will see via uart what happens after modifying the libs. Added after 12 [minutes]: . . I just combined as much as possible to make the esp work as short as possible. I don't want to make excuses ... . This is the SCL line although probably if the esp was loaded more then the sampling would probably drop below 100kHz Added after 44 [minutes]: So I checked this delay in the functions from BME. Unfortunately any delay other than 100ms in the while loop (isReadingCalibration()); returns the result of the nan measurement, which is not a number in float encoding. I will check later this library from bosch

khoam · Answer

. I didn't mean delay() in the while loop (isReadingCalibration()), but it's at the end of the Adafruit_BME280::init() function Code: C / C++Log in, to see the code

Zubiik · Answer

Well understood that delay I was changing, fact it's not in the loop, my mistake.

Zubiik · Answer

OK I took this library from sparkfun, and now about 233ms elapses from reset to ESP sleep. This includes 100ms for start up and 40ms for measuring and sending data, where the current peak is 93mA in 10ms. Unfortunately I am not able to determine if the data is being sent correctly because as I wrote before, yesterday I fried myself an ESP that was working as a slave, tomorrow it will be new. I think that these results are very good, I intend to take measurements once every 10...15 minutes so the battery must last for a year (although I haven't counted it exactly yet), especially that the data will be sent only if the values of the new measurement are different from the values of the previous measurement,for this I will use the RTC memory.

Zubiik · Answer

So it works. No problem connecting to the slave, nor does the slave make problems when connecting to the network when you need to send data. I am impressed how low the power consumption of these esps can go. I think they can compete with NRF chips. Oddly enough, I could only find one topic about espNow on the internet, hmm why not post something about it in the future? To conclude this offtopic, I would like to share my results. As far as the oscilloscope measured it correctly, with all the measuring and sending it came out 7mAs, sometimes it is a bit less sometimes more.

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khoam · Answer

. Starch, starch about that low power consumption, as there are a lot of rumours so far about the current consumption of the ESP8266 in deep-sleep. Which module from ESP are you using? By the way, I guess you can still go down with the BME initiation time by storing the state of the initialised object in RTC memory and replaying it after the wake-up instead of reinitialising it. But if you are happy with the results ...

Zubiik · Answer

Haha meaning I know what to do I'm running on esp 07 the one with the ceramic antenna, I blew the leds right away, same in the BME module the 3.3V stabiliser. BME is in FORCE mode. At the moment I still want to polish the code so that it doesn't send data when the last measurement is the same as the current one. Well, and generally do some tidying up. The esp12E works as a slave

krzbor · Answer

In order to save energy, we usually use deep-sleep. ESP has another interesting CH_PD pinout offering even lower power consumption. Of course there is the problem of wake-up, but if we have an RTC, it is worth thinking about a circuit with an alarm. Such a circuit can periodically wake everything up.

Zubiik · Answer

As far as I understood the documentation, when ch_pd is in low state, even rtc doesn't work. Yes, it is possible to combine with additional microcontroller e.g. attiny4 or similar, which would control this leg. This was on my mind when I was trying to do this project, but after trying Deep sleep I decided that this function meets my expectations.

khoam · Answer

. Putting LOW on CHIP_EN cuts power to the whole chip, so the RTC memory is also turned off.

krzbor · Answer

You wrote RTC. I thought you meant a real RTC e.g. type DS1337. Otherwise my statement makes no sense .

Zubiik · Answer

Well I didn't specify also cool. One other thought occurs to me.... If you look at these oscillograms you can see that the microcontroller itself takes about 80ms to start. I guess that's how long it takes to start oscillator and stabilize PLL, couldn't it be somehow speeded up?

khoam · Answer

This timing is mainly due to the 'spitting out' of diagnostic information on the UART, regardless of whether it is further transmitted or not. Theoretically, it would be possible to disable the sending of this information, but this already requires rebuilding the entire Arduino Core and NonOS-SDK on which the is based.

ESP8266 connecting to the network after ESP.deepSleepInstant() command

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