I have an ESP32 microcontroller with MicroPython 1.19.1 that I'm setting up as a wifi access point. But, when I attempt to print the IP address with print(f'{wlan.ifconfig()}') it gets stuck in a reboot loop.
Here's the code in my boot.py:
from network import WLAN, AP_IF
from config import AP_NAME, AP_PASS
print('Starting in wifi access point mode...')
wlan = WLAN(AP_IF)
wlan.config(authmode=3, essid=AP_NAME, password=AP_PASS)
wlan.active(True)
while (wlan.active() == False):
print('.')
print(f'SSID: {AP_NAME}')
print(f'Password: {AP_PASS}')
print(f'{wlan.ifconfig()}')
Commenting out the print(f'{wlan.ifconfig()}') fixes the reboot loop, as does inserting a delay just before the statement.
This leads me to believe the access point is not fully ready by the time I'm calling ifconfig(). But, I'm working under the assumption the while (wlan.active() == False) is supposed to take care of that. Though in the serial output, there's not a single dot printed to indicate it looped even once.
Serial output looks like this (after inserting a delay to mitigate the reboot loop):
Starting in wifi access point mode...
SSID: Lab
Password: ********
('192.168.4.1', '255.255.255.0', '192.168.4.1', '0.0.0.0')
If the while loop were actually waiting for the access point to come up, I would expect a few lines with dots between the 'Starting' message and the printing of SSID. So I'm thinking wlan.active() is just telling me what I set in the line above: wlan.active(True) and is not a true reflection of the access point's readiness.
I tried help(wlan) to see what methods might be available to determine the state of the access point. Some of the more promising ones and their results are shown below.
>>> wlan.active()
True
>>> wlan.isconnected()
False
>>> wlan.status()
>>>
I'm not surprised by isconnected() returning false since it's probably just for wifi station mode. I had high hopes for status(), but it only returns None
Every tutorial I've found so far uses the while loop to check active(), but obviously that's not working. Sticking a random delay in seems like a bad solution.
Is there a reliable way to ensure the access point is fully ready before asking for its IP address?
If I have:
analogWrite(4, 123);
Do I need to turn the PWM off like this:
analogWrite(4, 0);
If I'd like to set pin HIGH or LOW?
digitalWrite(4, HIGH);
In practice, changing pin HIGH/LOW works without turning PWM off but I'm encountering some unexpected behavior (my ESP8266 hangs) and I wonder if that could be the problem?
On my NodeMCU, once you call analogWrite on a pin, any later calls to digitalWrite have no effect; you're doomed to using analogWrite(pin, 0) or analogWrite(pin, PWMRANGE) which seems to work just fine.
Yeah I know there is similar questions in this community But they didn't help.
It's for some days that I play with SIM800l.It's response to my at commands is good but when I want to send SMS I'll get problem.I think this Screenshot says most of story:
AT commands and response
https://ibb.co/bXxwFQ
u can see that I have signal (AT+CSQ = 19).but my module can't find and connect to operator (forgot to test AT+CREG but it returns 0,3)
and I can set CREG to 1,3 by AT+CREG=1 command.Does it help?
oh at last I should say that I'm using lm2596 for supplying and my module blinks 70 times in a minute.more than 1 time in a sec (searching for network) and less than 2 time in a sec (connected)
ANY help would be appreciated
Maybe you're not powering it up with enough supply. Your module does not automatically register to network. It happened to me when I power my sim800l with the arduino 5v, it works smoothly at first but it keeps on resetting after a while. Try to use at commands such as cband, cops, creg, and csca to manually register to network.
Does anyone know if there is an API to get the current monitor state (on or off) in Windows (XP/Vista/2000/2003)?
All of my searches seem to indicate there is no real way of doing this.
This thread tries to use GetDevicePowerState which according to Microsoft's docs does not work for display devices.
In Vista I can listen to GUID_MONITOR_POWER_ON but I do not seem to get events when the monitor is turned off manually.
In XP I can hook into WM_SYSCOMMAND SC_MONITORPOWER, looking for status 2. This only works for situations where the system triggers the power off.
The WMI Win32_DesktopMonitor class does not seem to help out as well.
Edit: Here is a discussion on comp.os.ms-windows.programmer.win32 indicating there is no reliable way of doing this.
Anyone else have any other ideas?
GetDevicePowerState sometimes works for monitors. If it's present, you can open the \\.\LCD device. Close it immediately after you've finished with it.
Essentially, you're out of luck—there is no reliable way to detect the monitor power state, short of writing a device driver and filtering all of the power IRPs up and down the display driver chain. And that's not very reliable either.
You could hook up a webcam, point it at your screen and do some analysis on the images you receive ;)
Before doing anything based on the monitor state, just remember that users can use a machine with remote desktop of other systems that don't require a monitor connected to the machine - so don't turn off any visualization based on the monitor state.
You can't.
Look like all monitor power capabilities connected to the "power safe mode"
After searching i found here code that connecting between SC_MONITORPOWER message and system values (post number 2)
I use the code to testing if the system values is changing when i am manually switch off the monitor.
int main()
{
for(;monitorOff()!=1;)
Sleep(500);
return 0;
}//main
And the code is never stopped, no matter how long i am switch off my monitor.
There the code of monitorOff function:
int monitorOff()
{
const GUID MonitorClassGuid =
{0x4d36e96e, 0xe325, 0x11ce,
{0xbf, 0xc1, 0x08, 0x00, 0x2b, 0xe1, 0x03, 0x18}};
list<DevData> monitors;
ListDeviceClassData(&MonitorClassGuid, monitors);
list<DevData>::iterator it = monitors.begin(),
it_end = monitors.end();
for (; it != it_end; ++it)
{
const char *off_msg = "";
//it->PowerData.PD_PowerStateMapping
if (it->PowerData.PD_MostRecentPowerState != PowerDeviceD0)
{
return 1;
}
}//for
return 0;
}//monitorOff
Conclusion : when you manually switch of the the monitor, you cant catch it by windows (if there is no unusual driver interface for this), because all windows capabilities is connected to "power safe mode".
In Windows XP or later you can use the IMSVidDevice Interface.
See
http://msdn.microsoft.com/en-us/library/dd376775(VS.85).aspx
(not sure if this works in Sever 2003)
With Delphi code, you can detect invalid monitor geomerty while standby in progress:
i := 0
('Monitor'+IntToStr(i)+': '+IntToStr(Screen.Monitors[i].BoundsRect.Left)+', '+
IntToStr(Screen.Monitors[i].BoundsRect.Top)+', '+
IntToStr(Screen.Monitors[i].BoundsRect.Right)+', '+
IntToStr(Screen.Monitors[i].BoundsRect.Bottom))
Results:
Monitor geometry before standby:
Monitor0: 0, 0, 1600, 900
Monitor geometry while standby in Deplhi7:
Monitor0: 1637792, 4210405, 31266576, 1637696
Monitor geometry while standby in DeplhiXE:
Monitor0: 4211194, 40, 1637668, 1637693
This is a really old post but if it can help someone, I have found a solution to detect a screen being available or not : the Connecting and Configuring Displays (CCD) API of Windows.
It's part of User32.ddl and the interesting functions are GetDisplayConfigBufferSizes and QueryDisplayConfig. It give us all informations that can be viewed in the Configuration Panel of windows.
In particular the PathInfo contains a TargetInfo property that have a targetAvailable flag. This flag seems to be correctly updated on all the configurations I have tried so far.
This allow you to know the state of every screens connected to the PC and set their configurations.
Here a CCD wrapper for .Net
If your monitor has some sort of built-in USB hub, you could try and use that to detect if the monitor is off/on.
This will of course only work if the USB hub doesn't stay connected when the monitor is consider "off".
I'm working with the NetworkUtils.java class created by Sameer Nafdey in his blog post regarding accuiring a network connection within a Blackberry Application. However I recently noticed that my application was using the cell network even when a WiFi connection was available. I realized this was the case when we tested the application on a Torch with no SIM card and the app failed. After some debugging I found that:
if (WLANInfo.getWLANState() == WLANInfo.WLAN_STATE_CONNECTED){...}
was returning false despite the fact that the WiFi network was setup correctly (I was able to use web browser to visit Google). We had to return the Torch but while debugging the app in the simulator I noticed that if WiFi was on but the Data Network was turned off then this call would work correctly. However I would then get an exception (java.io.ioexception: Radio is off) when executing this block:
httpConnector = (HttpConnection)Connector.open(URL);
httpConnector.setRequestMethod(HttpConnection.GET);
httpConnector.setRequestProperty("Content-Type", "text/plain; charset=UTF-8");
in = httpConnector.openInputStream();
I've seen a lot of issues related to the Torch's WiFi connectivity problems but I'm currently concerned that this behavior may also be affecting other models. Anyone seen anything like this or have an idea of how to fix it?
You could try:
if( RadioInfo.areWAFsSupported( RadioInfo.WAF_WLAN )
&&
( RadioInfo.getActiveWAFs() & RadioInfo.WAF_WLAN ) != 0
&&
CoverageInfo.isCoverageSufficient( 1 , RadioInfo.WAF_WLAN, false) )
{ ... }
It's been working so far, on Blackberry OS 6.0 (Torch 9800). Tested on device and sim.