Author: acassis

Using GSM Modem on NuttX with DNS support

I already demonstrated how to use NuttX with GSM modem. But I realized that it wasn’t with DNS support enabled. Then I decided to enable DNS and test it again:

 ATE1
 OK
 chat: OK AT+CGDCONT=1,"IP","tim.br"
 AT+QACCM=0,0
 OK
 chat: OK ATD99**1#
 AT+CGDCONT=1,"IP","tim.br"
 OK
 chat: CONNECT 
 ATD99**1#
 CONNECT
 IP: 192.168.254.254 
 IP: 100.86.71.207 IP: 100.86.71.207 
nsh> mount -t procfs /proc
nsh> ifconfig
ppp0    Link encap:TUN at UP
        inet addr:100.86.71.207 DRaddr:192.168.254.254 Mask:0.0.0.0
nsh> ?
help usage:  help [-v] []
[         cp        exec      hexdump   mh        set       umount    
  ?         cmp       exit      ifconfig  mount     sh        unset     
  addroute  date      false     kill      mw        sleep     usleep    
  break     dd        free      ls        nslookup  test      xd        
  cat       echo      help      mb        ps        true      
Builtin Apps:
  ping        testlogbuf  leds        pppd        
nsh> nslookup google.com
Host: google.com  IPv4 Addr: 172.217.29.110
nsh> ping google.com
PING 172.217.29.110 56 bytes of data
56 bytes from 172.217.29.110: icmp_seq=0 time=420 ms
56 bytes from 172.217.29.110: icmp_seq=1 time=490 ms
56 bytes from 172.217.29.110: icmp_seq=2 time=530 ms
56 bytes from 172.217.29.110: icmp_seq=3 time=840 ms
56 bytes from 172.217.29.110: icmp_seq=4 time=410 ms
56 bytes from 172.217.29.110: icmp_seq=5 time=500 ms
56 bytes from 172.217.29.110: icmp_seq=6 time=540 ms
56 bytes from 172.217.29.110: icmp_seq=7 time=590 ms
56 bytes from 172.217.29.110: icmp_seq=8 time=640 ms
56 bytes from 172.217.29.110: icmp_seq=9 time=680 ms
10 packets transmitted, 10 received, 0% packet loss, time 10100 ms
nsh> 

I just followed the video tutorial #044:

Ping on NuttX returning EALREADY

After the GSM modem connection I’m trying to “ping 8.8.8.8” and it is returning an error:

 ATZ
 OK
 chat: cmd 1, arg ON
 chat: cmd 4, arg 30
 chat:  ATE1
 chat: OK AT+QACCM=0,0
 ATE1
 OK
 chat: OK AT+CGDCONT=1,"IP","tim.br"
 AT+QACCM=0,0
 OK
 chat: OK ATD99**1#
 AT+CGDCONT=1,"IP","tim.br"
 OK
 chat: CONNECT 
 ATD99**1#
 CONNECT
 IP: 192.168.254.254 
 IP: 100.74.7.202 
 IP: 100.74.7.202 
 nsh> ifconfig
 nsh: ifconfig: opendir failed: 20
 nsh> mount -t procfs /proc
 nsh> free
              total       used       free    largest
 Umem:        24416      15016       9400       9400
 nsh> ifconfig
 ppp0    Link encap:TUN at UP
         inet addr:100.74.7.202 DRaddr:192.168.254.254 Mask:0.0.0.0
 nsh> ping 8.8.8.8
 PING 8.8.8.8 56 bytes of data
 No response from 8.8.8.8: icmp_seq=0 time=1000 ms
 No response from 8.8.8.8: icmp_seq=1 time=1000 ms
 No response from 8.8.8.8: icmp_seq=2 time=1000 ms
 No response from 8.8.8.8: icmp_seq=3 time=1000 ms
 No response from 8.8.8.8: icmp_seq=4 time=1000 ms
 No response from 8.8.8.8: icmp_seq=5 time=1000 ms
 No response from 8.8.8.8: icmp_seq=6 time=1000 ms
 ERROR: sendto failed at seqno 7: 114
 7 packets transmitted, 0 received, 100% packet loss, time 7070 ms
 nsh>

I suspect the issue is in the Mobile Operator TIM

UPDATE: I was using a bad antenna. Using a better GSM antenna everything worked fine:

Blender VSE using animation on Transform effect

Blender is a very powerful 3D software, but it also has internally a good Video Editor (VSE – Video Sequence Editor).

If you want to learn it, there is a good video tutorial playlist here:

The Blender VSE has a very power effect feature called Transform, you just select the your video strip and Add -> Effect Strip -> Transform. Then you can offset, zoom in/out, rotate, etc.

But it is also possible to use Keyframe with Transform, but it is a little bit tricker because it doesn’t follow the traditional Blender way. You need to edit the Transform strip Properties (press N case it is not visible) and edit the values, for each edited value press ENTER to confirm and then type I to Insert keyframe.

If it worked you will see the Property field changing its color to yellow: