<?xml version="1.0" encoding="UTF-8"?><rss xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:content="http://purl.org/rss/1.0/modules/content/" xmlns:atom="http://www.w3.org/2005/Atom" version="2.0"><channel><title><![CDATA[Connecting to WIFI: Guru Meditation Error]]></title><description><![CDATA[<p dir="auto">Hi,</p>
<p dir="auto">i am currently trying to connect to a WPA2-Enterprise (eduroam) network as described <a href="https://docs.pycom.io/tutorials/all/wlan/" target="_blank" rel="noopener noreferrer nofollow">here</a> on a Lopy4 with Pysense Expansion board.<br />
This is my <code>main.py</code> file (no other files are used in this project):</p>
<pre><code>from network import WLAN
from machine import SD
import os
import time

sd = SD()
os.mount(sd, '/sd')

wlan = WLAN(mode=WLAN.STA)
nets = wlan.scan()
for net in nets:
    print(net.ssid)
    print(net.channel)
    if net.ssid == &quot;eduroam&quot; and wlan.channel() == net.channel:
        print('Wifi found. connecting.')
        wlan.connect(ssid='eduroam', auth=(WLAN.WPA2_ENT, '[username]', '[pw]'),
                     identity='[identy]', ca_certs='/sd/cert/ca.pem')
        break
</code></pre>
<p dir="auto">The device boots up and runs the script without error. However <code>wlan.isconnected()</code> will always return <code>False</code>.</p>
<p dir="auto">Then, after a couple of seconds the device crashes with the error message:</p>
<pre><code>&gt;&gt;&gt; Guru Meditation Error: Core  0 panic'ed (LoadProhibited)
. Exception was unhandled.
Register dump:
PC      : 0x40188721  PS      : 0x00060630  A0      : 0x801832fa  A1      : 0x3ffe39f0
A2      : 0x3ffe3f9c  A3      : 0x00000001  A4      : 0x3fbc64a4  A5      : 0x00000001
A6      : 0x3ffe3ac4  A7      : 0x00000001  A8      : 0x8018871d  A9      : 0x3ffe4988
A10     : 0x00000000  A11     : 0x000000ff  A12     : 0x3ffe3f9c  A13     : 0x00000000
A14     : 0x00000002  A15     : 0x00000005  SAR     : 0x00000018  EXCCAUSE: 0x0000001c
EXCVADDR: 0x00000001  LBEG    : 0x40187509  LEND    : 0x4018750f  LCOUNT  : 0x00000000
</code></pre>
<p dir="auto">After a long sequence of printed core dumping the system will restart.</p>
<p dir="auto">The device is apparently setting up the connection in the background and will at some point fail. I investigated the Guru Meditation error (details <a href="https://docs.espressif.com/projects/esp-idf/en/latest/api-guides/fatal-errors.html" target="_blank" rel="noopener noreferrer nofollow">here</a>) and found that:</p>
<p dir="auto">LoadProhibited, StoreProhibited:</p>
<p dir="auto">This CPU exception happens when application attempts to read from or write to an invalid memory location. The address which was written/read is found in EXCVADDR register in the register dump. If this address is zero, it usually means that application attempted to dereference a NULL pointer. If this address is close to zero, it usually means that application attempted to access member of a structure, but the pointer to the structure was NULL. If this address is something else (garbage value, not in 0x3fxxxxxx - 0x6xxxxxxx range), it likely means that the pointer used to access the data was either not initialized or was corrupted.</p>
<p dir="auto">So apparently the application attempted to access member of a structure, but the pointer to the structure was NULL. That doesn't really help me, however.</p>
<p dir="auto">Is anybody facing the same problem or has some advice?</p>
<p dir="auto"><strong>Notes on the code:</strong></p>
<p dir="auto">I am checking <code>wlan.channel()==net.channel()</code> as eduroam is available at least twice on different channels. The Lopy4 is set on channel 6 and I also find on instance of eduroam on this channel. I don't know if that is important as my problem persists and I can't connect to WIFI either way.</p>
<p dir="auto">The <code>ca.pem</code> file that I have stored on SD is the same that I am using on my Ubuntu Laptop to (successfully) connect to eduroam.</p>
]]></description><link>https://forum.pycom.io/topic/5026/connecting-to-wifi-guru-meditation-error</link><generator>RSS for Node</generator><lastBuildDate>Tue, 12 May 2026 03:49:02 GMT</lastBuildDate><atom:link href="https://forum.pycom.io/topic/5026.rss" rel="self" type="application/rss+xml"/><pubDate>Thu, 18 Jul 2019 11:57:58 GMT</pubDate><ttl>60</ttl><item><title><![CDATA[Reply to Connecting to WIFI: Guru Meditation Error on Thu, 18 Jul 2019 11:57:58 GMT]]></title><description><![CDATA[<p dir="auto">Hi,</p>
<p dir="auto">i am currently trying to connect to a WPA2-Enterprise (eduroam) network as described <a href="https://docs.pycom.io/tutorials/all/wlan/" target="_blank" rel="noopener noreferrer nofollow">here</a> on a Lopy4 with Pysense Expansion board.<br />
This is my <code>main.py</code> file (no other files are used in this project):</p>
<pre><code>from network import WLAN
from machine import SD
import os
import time

sd = SD()
os.mount(sd, '/sd')

wlan = WLAN(mode=WLAN.STA)
nets = wlan.scan()
for net in nets:
    print(net.ssid)
    print(net.channel)
    if net.ssid == &quot;eduroam&quot; and wlan.channel() == net.channel:
        print('Wifi found. connecting.')
        wlan.connect(ssid='eduroam', auth=(WLAN.WPA2_ENT, '[username]', '[pw]'),
                     identity='[identy]', ca_certs='/sd/cert/ca.pem')
        break
</code></pre>
<p dir="auto">The device boots up and runs the script without error. However <code>wlan.isconnected()</code> will always return <code>False</code>.</p>
<p dir="auto">Then, after a couple of seconds the device crashes with the error message:</p>
<pre><code>&gt;&gt;&gt; Guru Meditation Error: Core  0 panic'ed (LoadProhibited)
. Exception was unhandled.
Register dump:
PC      : 0x40188721  PS      : 0x00060630  A0      : 0x801832fa  A1      : 0x3ffe39f0
A2      : 0x3ffe3f9c  A3      : 0x00000001  A4      : 0x3fbc64a4  A5      : 0x00000001
A6      : 0x3ffe3ac4  A7      : 0x00000001  A8      : 0x8018871d  A9      : 0x3ffe4988
A10     : 0x00000000  A11     : 0x000000ff  A12     : 0x3ffe3f9c  A13     : 0x00000000
A14     : 0x00000002  A15     : 0x00000005  SAR     : 0x00000018  EXCCAUSE: 0x0000001c
EXCVADDR: 0x00000001  LBEG    : 0x40187509  LEND    : 0x4018750f  LCOUNT  : 0x00000000
</code></pre>
<p dir="auto">After a long sequence of printed core dumping the system will restart.</p>
<p dir="auto">The device is apparently setting up the connection in the background and will at some point fail. I investigated the Guru Meditation error (details <a href="https://docs.espressif.com/projects/esp-idf/en/latest/api-guides/fatal-errors.html" target="_blank" rel="noopener noreferrer nofollow">here</a>) and found that:</p>
<p dir="auto">LoadProhibited, StoreProhibited:</p>
<p dir="auto">This CPU exception happens when application attempts to read from or write to an invalid memory location. The address which was written/read is found in EXCVADDR register in the register dump. If this address is zero, it usually means that application attempted to dereference a NULL pointer. If this address is close to zero, it usually means that application attempted to access member of a structure, but the pointer to the structure was NULL. If this address is something else (garbage value, not in 0x3fxxxxxx - 0x6xxxxxxx range), it likely means that the pointer used to access the data was either not initialized or was corrupted.</p>
<p dir="auto">So apparently the application attempted to access member of a structure, but the pointer to the structure was NULL. That doesn't really help me, however.</p>
<p dir="auto">Is anybody facing the same problem or has some advice?</p>
<p dir="auto"><strong>Notes on the code:</strong></p>
<p dir="auto">I am checking <code>wlan.channel()==net.channel()</code> as eduroam is available at least twice on different channels. The Lopy4 is set on channel 6 and I also find on instance of eduroam on this channel. I don't know if that is important as my problem persists and I can't connect to WIFI either way.</p>
<p dir="auto">The <code>ca.pem</code> file that I have stored on SD is the same that I am using on my Ubuntu Laptop to (successfully) connect to eduroam.</p>
]]></description><link>https://forum.pycom.io/post/28783</link><guid isPermaLink="true">https://forum.pycom.io/post/28783</guid><dc:creator><![CDATA[pyoneer]]></dc:creator><pubDate>Thu, 18 Jul 2019 11:57:58 GMT</pubDate></item></channel></rss>