I am thinking about getting a new monitor. Short of plugging one in and seeing what happens, how can I tell if my laptop can output 4k resolution?
Is there a command I can run that will tell me this?
I thought maybe I could xrandr, but I think that only tells me what each monitor is capable of (even if the controller is capable of more.)
I also thought maybe I could look up the device from the lspci and find it on google, but I couldn't find much.
My lspci -v says:
00:02.0 VGA compatible controller: Intel Corporation 3rd Gen Core processor Graphics Controller (rev 09) (prog-if 00 [VGA controller])
Subsystem: Lenovo Device 500d
Flags: bus master, fast devsel, latency 0, IRQ 45
Memory at f3000000 (64-bit, non-prefetchable) [size=4M]
Memory at d0000000 (64-bit, prefetchable) [size=256M]
I/O ports at 6000 [size=64]
Expansion ROM at <unassigned> [disabled]
Capabilities: <access denied>
Kernel driver in use: i915
Update: Mr. Llama's suggestion about xrandr made me think that this output could be useful to someone who knows more than I do. Here's my xrandr:
Screen 0: minimum 8 x 8, current 5206 x 1080, maximum 16384 x 16384
eDP-1-0 connected 1366x768+0+0 309mm x 173mm
1366x768 60.1*+
... other resolution options removed for brevity ...
320x240 60.1
HDMI-1-0 connected 1920x1080+3286+0 160mm x 90mm
1920x1080 60.0*+ 50.0 59.9
... other resolution options removed for brevity ...
640x480 60.0 59.9
DisplayPort-1-1 connected 1920x1080+1366+0 509mm x 286mm
1920x1080 60.0*+
... other resolution options removed for brevity ...
720x400 70.1
VGA-1-0 disconnected
HDMI-1-1 disconnected
DisplayPort-1-0 disconnected
Looks like the xrandr command might be of use to you. It lists the available and current monitor resolution.
See this SuperUser question for more information.
Related
I am working with the Songhe Mega2560 + WiFi R3 Mega2560 + ESP8266 4MB Memory integrated circuit for a project involving connecting to a WiFi signal and reading the RSSI value.
Below is a basic sketch that I uploaded to the Mega2560 to communicate to the ESP8266 through Serial3 to test the firmware:
#include "WiFiEsp.h"
// Emulate Serial3 on pins 6/7 if not present
#ifndef HAVE_HWSERIAL3
#include "SoftwareSerial.h"
SoftwareSerial Serial3(6, 7); // RX, TX
#endif
void setup() {
// initialize serial for debugging
Serial.begin(115200);
// initialize serial for ESP module
Serial3.begin(115200);
// initialize ESP module
WiFi.init(&Serial3);
// check for the presence of the shield
if (WiFi.status() == WL_NO_SHIELD) {
Serial.println("WiFi shield not present");
// don't continue
while (true);
}
// Print WiFi MAC address
printMacAddress();
}
void loop() {
// do nothing
}
I flashed different versions of espressif's AT firmware but the serial monitor keeps showing this:
22:28:07.009 -> [WiFiEsp] Initializing ESP module
22:28:08.023 -> [WiFiEsp] >>> TIMEOUT >>>
22:28:10.026 -> [WiFiEsp] >>> TIMEOUT >>>
22:28:12.022 -> [WiFiEsp] >>> TIMEOUT >>>
22:28:14.023 -> [WiFiEsp] >>> TIMEOUT >>>
22:28:16.020 -> [WiFiEsp] >>> TIMEOUT >>>
22:28:17.006 -> [WiFiEsp] Cannot initialize ESP module
22:28:23.017 -> [WiFiEsp] >>> TIMEOUT >>>
22:28:23.017 -> [WiFiEsp] No tag found
22:28:23.017 -> WiFi shield not present
I am not sure if it is a firmware issue so I have tried multiple versions of AT firmware. The baud rate I have set is 115200. I have been looking at many other sources online, but I cannot seem to initialize WiFiEsp's WiFi module and I would really appreciate some help on this matter.
I have been following these steps for flashing and testing.
Toggle DIP switches 5,6,7 to ON and all else OFF and RXD/TXD to RXD0
Connect USB cable from port COM3 (on my computer) to integrated PCB with Mega2560 + ESP8266 WiFi
Use esptool.py to flash firmware to the ESP8266
The latest, released firmware for ESP8266 is the "ESP8266-IDF-AT_V2.2.1.0.zip" downloadable at espressif.com
I download the factory_xxx.bin to address 0 since I read that it indicates all hardware configurations for the ESP module. Below is the command I ran:
esptool.py --chip auto --port COM3 --baud 115200 --before default_reset --after hard_reset write_flash -z --flash_mode dio --flash_size 4MB 0x0 factory_WROOM-02.bin
Disconnect USB cable
Toggle DIP switches 1,2,3,4 to ON and all else OFF and RXD/TXD to RXD3
Connect USB cable and upload sketch with Arduino IDE and read serial monitor
This is the procedure I have been trying to debug. If anymore information is required for better help, please let me know and I will try my best to provide.
The screenshot below is the command I run which successfully flashes (I think):
C:\Users\[MY NAME]\Downloads\ESP8266_NONOS_SDK-3.0.5\ESP8266_NONOS_SDK-3.0.5\bin>esptool.py write_flash --flash_mode dout --flash_size 4MB-c1 0x0 boot_v1.7.bin 0x01000 at/1024+1024/user1.2048.new.5.bin 0x1fb000 blank.bin 0x1fc000 esp_init_data_default_v08.bin 0xfe000 blank.bin 0x1fe000 blank.bin
esptool.py v4.4
Found 1 serial ports
Serial port COM3
Connecting....
Detecting chip type... Unsupported detection protocol, switching and trying again...
Connecting....
Detecting chip type... ESP8266
Chip is ESP8266EX
Features: WiFi
Crystal is 26MHz
MAC: a4:e5:7c:b6:77:c0
Uploading stub...
Running stub...
Stub running...
Configuring flash size...
Flash will be erased from 0x00000000 to 0x00000fff...
Flash will be erased from 0x00001000 to 0x00065fff...
Flash will be erased from 0x001fb000 to 0x001fbfff...
Flash will be erased from 0x001fc000 to 0x001fcfff...
Flash will be erased from 0x000fe000 to 0x000fefff...
Flash will be erased from 0x001fe000 to 0x001fefff...
Flash params set to 0x0360
Compressed 4080 bytes to 2936...
Wrote 4080 bytes (2936 compressed) at 0x00000000 in 0.4 seconds (effective 92.5 kbit/s)...
Hash of data verified.
Compressed 413556 bytes to 296987...
Wrote 413556 bytes (296987 compressed) at 0x00001000 in 26.2 seconds (effective 126.1 kbit/s)...
Hash of data verified.
Compressed 4096 bytes to 26...
Wrote 4096 bytes (26 compressed) at 0x001fb000 in 0.1 seconds (effective 373.3 kbit/s)...
Hash of data verified.
Compressed 128 bytes to 75...
Wrote 128 bytes (75 compressed) at 0x001fc000 in 0.1 seconds (effective 11.8 kbit/s)...
Hash of data verified.
Compressed 4096 bytes to 26...
Wrote 4096 bytes (26 compressed) at 0x000fe000 in 0.1 seconds (effective 365.1 kbit/s)...
Hash of data verified.
Compressed 4096 bytes to 26...
Wrote 4096 bytes (26 compressed) at 0x001fe000 in 0.1 seconds (effective 357.1 kbit/s)...
Hash of data verified.
Leaving...
Hard resetting via RTS pin...
After this, I test it with Arduino's SerialPassThrough sketch replacing Serial1 with Serial3 and I get no response from running the command: AT.
I would appreciate any help on how to resolve this and where I could possibly be going wrong. Thanks!
I am trying out the NREAL Air, and after extensive testing I've found that it is more comfortable for me to use it at the not-edid-available 90 Hz mode. I was able to find this by setting the following parameters in the "screen" section of my xorg conf.
Option "UseEDID" "false"
Option "ModeDebug" "true”
Option "ExactModeTimingsDVI" "true"
Option "ModeValidation" "NoEdidModes, NoMaxPClkCheck, AllowNonEdidModes"
And then appropriately configuring the rest of my xorg.conf. See https://gist.github.com/cnlohr/9375d6fc0097b50f73c4da7b75a20e83
This has the added beneift of you being able to use custom ModeLine with xrandr. Which is awesome, btw!
sudo xrandr --output DP-2 --newmode HS2 200 1920 1952 1968 2000 1080 1089 1094 1250 +hsync +vsync
sudo xrandr --addmode DP-2 HS2
sudo xrandr --output DP-2 --mode HS2
But, this does not work with display managers, like lightdm, which switch into my desired mode, and then immediately switch to the default 1024x768 for both monitors, which my laptop display cannot handle.
It does, however, work with startx but I'd rather not use my system that way, as I like display managers.
Even if I use custom ModeValidation commands, as soon as I don't disable UseEDID the NVIDIA drivers seem to block xrandr from doing any particularly interesting modes, failing with the following error:
X Error of failed request: BadMatch (invalid parameter attributes)
Major opcode of failed request: 140 (RANDR)
Minor opcode of failed request: 18 (RRAddOutputMode)
Serial number of failed request: 45
Current serial number in output stream: 46
So, I'm in a bit of a pickle. If I want to use the smoother, less headache-inducing mode for the NREAL AIR, I can't use EDIDs, but what is a life without EDIDs?
I have this LCD panel:
LED panel's backlight is driven by the MIC2297 chip which takes two signals:
BRT - PWM signal for setting brightness of the LCD's background LEDs.
BL_EN that - gpio signal that enables or disables the LCD's background LEDs.
MIC2297 is powered from the +12V.
Now I connected this display to the Beaglebone Black's (BBB's) expansion connector and I am already running Linux on the BBB's microcontroller AM335x.
In order to enable the backlight I have to properly define it in the device tree i.e. .dts file. Currently I managed to set this up:
backlightt: backlight {
compatible = "pwm-backlight";
pwms = <&ehrpwm1 0 500000000>;
power-supply <>; // ???
enable-gpios = <&gpio2 3 0>;
brightness-levels = <0 4 8 16 32 64 128 255>;
default-brightness-level = <7>;
};
What I don't understand is the property power-supply. How can I know which regulator to use? My devicce uses external 12V! This is really confusing! Why do we even have to specify the regulator?
I found solution...
PWM backlight requires a property "power-supply" that points to some regulator inside the AM335x. This regulator is used to set the output voltage of the PWM - so we don't need to put any kind of voltage regulator between an AM335x and the backlight IC (which might only support 1.5V PWM input on some mobile devices). This is actually really useful.
I am working with a Beaglebone Black and I would like to use the mmc2 slot.
according to AM335xx TRM, a beaglebone black should have 3 mmc available:
mmc0 (sd card);
mmc1 (2G flash),
mmc2.
I am trying to enable mmc2 by device tree (and I am quite sure to have the right pin settings) but, by doing
dmesg
I obtain:
/ocp/mmc#47810000: can't find DMA channel
omap_hsmmc mmc.11: unable to obtain RX DMA engine channel 65
By putting the oscilloscope probe on the header (e.g. the mmc2 clk signal), I do not see any transition.
I already removed R 160 to have mmc2 cmd accessible but I do not see any transition also there.
I tried both to enable it by
echo > /sys/devices/..../slots
and by
capemgr.enable_partno
with no success:
I can see it in
/sys/devices/..../slots
(with the L meaning loaded)..but no way to see any signal on the header.
I already googled it but answers are not clear at all.
Any ideas?
My
uname -a
is:
Linux beaglebone 3.8.13 #1 SMP Tue Jun 18 02:11:09 EDT 2013 armv7l GNU/Linux
Thanks for your help.
You need to configure the mmc2 DMA events to some DMA channel since these events are not direct mapped.
I was not able to do this successfully using device tree overlays. So I made a change in the
am335-x-bone-common.dtsi directly (not sure this is the best way though):
&edma {
ti,edma-xbar-event-map = <32 12>, /* gpevt2 -> 12 */
<30 20>, /* xdma_event_intr2 -> 20 */
+ <1 32>,
+ <2 33>;
};
In the example above the event 1 (SDTXEVT2) was mapped to channel 32 and event 2 (SDRXEVT2) to channel 33.
In case you want to pick another open DMA channel check tables 11-23. Direct Mapped and Table 11-24. Crossbar Mapped from the technical reference manual Rev J.
In your device tree overlay file add these channels in the mmc3 node:
dmas = <&edma 32
&edma 33>;
dma-names = "tx", "rx";
I'm trying to get RSSI or signal strength from WiFi packets.
I want also RSSI from 'WiFi probe requests' (when somebody is searching for a WiFi hotspots).
I managed to see it from kismet logs but that was only to make sure it is possible - I don't want to use kismet all the time.
For 'full time scanning' I'm using scapy. Does anybody know where can I find the RSSI or signal strength (in dBm) from the packets sniffed with scapy? I don't know how is the whole packet built - and there are a lot of 'hex' values which I don't know how to parse/interpret.
I'm sniffing on both interfaces - wlan0 (detecting when somebody connects to my hotspot), and mon.wlan0 (detecting when somebody is searching for hotspots).
Hardware (WiFi card) I use is based on Prism chipset (ISL3886). However test with Kismet was ran on Atheros (AR2413) and Intel iwl4965.
Edit1:
Looks like I need to access somehow information stored in PrismHeader:
http://trac.secdev.org/scapy/browser/scapy/layers/dot11.py
line 92 ?
Anybody knows how to enter this information?
packet.show() and packet.show2() don't show anything from this Class/Layer
Edit2:
After more digging it appears that the interface just isn't set correctly and that's why it doesn't collect all necessary headers.
If I run kismet and then sniff packets from that interface with scapy there is more info in the packet:
###[ RadioTap dummy ]###
version= 0
pad= 0
len= 26
present= TSFT+Flags+Rate+Channel+dBm_AntSignal+Antenna+b14
notdecoded= '8`/\x08\x00\x00\x00\x00\x10\x02\x94\t\xa0\x00\xdb\x01\x00\x00'
...
Now I only need to set the interface correctly without using kismet.
Here is a valuable scapy extension that improves scapy.layers.dot11.Packet's parsing of present not decoded fields.
https://github.com/ivanlei/airodump-iv/blob/master/airoiv/scapy_ex.py
Just use:
import scapy_ex
And:
packet.show()
It'll look like this:
###[ 802.11 RadioTap ]###
version = 0
pad = 0
RadioTap_len= 18
present = Flags+Rate+Channel+dBm_AntSignal+Antenna+b14
Flags = 0
Rate = 2
Channel = 1
Channel_flags= 160
dBm_AntSignal= -87
Antenna = 1
RX_Flags = 0
To summarize:
signal strength was not visible because something was wrong in the way that 'monitor mode' was set (not all headers were passed/parsed by sniffers). This monitor interface was created by hostapd.
now I'm setting monitor mode on interface with airmon-ng - tcpdump, scapy show theese extra headers.
Edited: use scapy 2.4.1+ (or github dev version). Most recent versions now correctly decode the « notdecoded » part
For some reason the packet structure has changed. Now dBm_AntSignal is the first element in notdecoded.
I am not 100% sure of this solution but I used sig_str = -(256 - ord(packet.notdecoded[-2:-1])) to reach first element and I get values that seems to be dBm_AntSignal.
I am using OpenWRT in a TP-Link MR3020 with extroot and Edward Keeble Passive Wifi Monitoring project with some modifications.
I use scapy_ex.py and I had this information:
802.11 RadioTap
version = 0
pad = 0
RadioTap_len= 36
present = dBm_AntSignal+Lock_Quality+b22+b24+b25+b26+b27+b29
dBm_AntSignal= 32
Lock_Quality= 8
If someone still has the same issue, I think I have found the solution:
I believe this is the right cut for the RSSI value:
sig_str = -(256-ord(packet.notdecoded[-3:-2]))
and this one is for the noise level:
noise_str = -(256-ord(packet.notdecoded[-2:-1]))
The fact that it says "RadioTap" suggests that the device may supply Radiotap headers, not Prism headers, even though it has a Prism chipset. The p54 driver appears to be a "SoftMAC driver", in which case it'll probably supply Radiotap headers; are you using the p54 driver or the older prism54 driver?
I have similar problem, I set up the monitor mode with airmon-ng and I can see the dBm level in tcpdump but whenever I try the sig_str = -(256-ord(packet.notdecoded[-4:-3])) I get -256 because the returned value from notdecoded in 0. Packet structure looks like this.
version = 0
pad = 0
len = 36
present = TSFT+Flags+Rate+Channel+dBm_AntSignal+b14+b29+Ext
notdecoded= ' \x08\x00\x00\x00\x00\x00\x00\x1f\x02\xed\x07\x05
.......