error: pll_cal exceeds 2ms! wifi issue

[DanielTerletzkiy]

Board

esp32c6

Device Description

dfrobot firebeetle 2

Hardware Configuration

this board has a waveshare display and is powered by a 2000mah battery

Version

latest development Release Candidate (RC-X)

IDE Name

Arduino IDE

Operating System

Windows 11

Flash frequency

80Mhz

PSRAM enabled

no

Upload speed

921600

Description

while operating on battery (as far as i know not happening while connected via usb) and waking up after deep-sleep mode (after a few hours of doing so), the device refuses to connect to any WiFI networks and prints this message into the Serial interface when booting: error: pll_cal exceeds 2ms!.

the board went to sleep and booted for about 5 days perfectly without fail and always connected to the internet afterwards, this issue started just yesterday, when i saw that the display had old data on it, when i plugged in my pc while on battery, i saw the message above and a constant reboot loop, because it cannot connect.

i have found out that the hardware reset button fixes this issue, but pressing this every time is not good enough, i have written code to reset the device via software, tried ESP.restart() that didn't work, abort() also without luck, next thing to try will be a cable connected with gpio to the rst button.

As of now i also don't know the exact time it takes for this problem to happen, but once it happens the device can only recover via hardware reset.

currently i also have not found any info on the internet, but i did find one that has the same board and problem as me here: esp8266/Arduino#2566 (comment)

i also opened a forum post on the dfrobot page here: https://www.dfrobot.com/forum/topic/334203

Sketch

setup
///
Serial.begin(115200);
analogReadResolution(12);

#ifdef DEVELOPMENT
    delay(1000);
#endif

    General::InitDevice()

////

 

RTC_DATA_ATTR unsigned long bootCount = 0;
RTC_DATA_ATTR unsigned long requestFails = 0;

 

void General::InitDevice() {
    Serial.println("---------------------");

    Serial.print("bootCount: ");
    Serial.println(bootCount);

    Serial.print("requestFails: ");
    Serial.println(requestFails);

    if (requestFails > 2) {
        abort();
        //ESP.restart();
    }

    Serial.println("Init Device");
    preferences.begin(PROJECT, false);

    ++bootCount;

    String uid = preferences.getString("uid", "");
    if (uid.length() <= 0) {
        uid = General::GenerateUUID();
        preferences.putString("uid", uid);
    }

    Serial.print("uid: ");
    Serial.println(uid);

    String hostname = PROJECT + String("-") + uid.substring(0, 8); //project name + first 8 chars from uid
    WiFiClass::setHostname(hostname.c_str());

    Serial.print("SSID: ");
    Serial.println(WIFI_SSID);

    uint8_t wifiFails = 0;

    WiFiClass::mode(WIFI_STA);
    //WiFi.setAutoReconnect(true);

    WiFi.begin(WIFI_SSID, WIFI_PASS);
    while (WiFiClass::status() != WL_CONNECTED) {
        delay(500);
        Serial.print(".");
        if (wifiFails > 24) {
            requestFails++;
            General::PutToSleep();
        }
        wifiFails++;
    }
    Serial.println("Connected!")

///


void General::PutToSleep(unsigned long microSeconds) {
    uptime += millis();
    General::UpdateStatus(DeviceState::SLEEP);

    //WiFi.setSleep(false);
    WiFi.disconnect();
    ESP.deepSleep(microSeconds);
}

Debug Message

pll_cal exceeds 2ms!
pll_cal exceeds 2ms!
bootCount: 2
requestFails: 2
Init Device
uid: f5bf7243-f04c-49d6-ab3a-0d179fb352cc
SSID: -redacted-
......................
(gets put to sleep, wakes up after 2 sec and tries again, 
after two tries it does abort(); and the cycle continues
)

Other Steps to Reproduce

No response

I have checked existing issues, online documentation and the Troubleshooting Guide

• I confirm I have checked existing issues, online documentation and Troubleshooting guide.

[lbernstone]

This is a power issue. I don't know how you are managing your power, but once the battery is unable to adequately supply the LDO, you are not going to get enough current to start WiFi.

[DanielTerletzkiy]

thank you for the quick answer!
with this i currently assume that i have a broken board from dfrobot.
The board itself just has a PH-2 battery header and should manage everything by itself as there is no documentation for it.
strange is also, that i can plug the usb-c cable into my computer and it still shows the pll_cal error message, even after i disconnect the battery.
If however i do a hardware reset (with and without battery) it will boot as if nothing happened...
my bet is definitely on a broken board, as i have never had problems with my type of battery since i used it on other esp32 boards in the past

[SuGlider]

This is not an Arduino issue. I'll transfer it to the discussion session. Please treck it there. Thanks.

[lbernstone]

Well, what I can tell you is that I have definitely seen that error pop up when the device was not getting enough current. I use a battery charger chip on my designs, and it allows adjustment of the current. At 100mA (with no battery), it gives this error. At 200mA, no error.