raspberry-pi3

问题 I'm working on voice recognition system with Raspberry pi 3B and while running some code I face some problem which is given below. I was tried so many stuffs from the internet but couldn't found some specific problem so please help me about below error! ALSA lib pcm.c:2495:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.rear ALSA lib pcm.c:2495:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.center_lfe ALSA lib pcm.c:2495:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.side ALSA lib pcm.c:2495:(snd

问题 I'm writing an audio decoding program for ALSA, which among others detects audio capabilities. It uses the snd_pcm_hw_params_get_XXX() functions for that. This works well on my Ubuntu PC but on Raspberry Pi 3 these calls return no information. They return success but the min and max values are meaningless. For instance the period: int err; snd_pcm_t *pcm; snd_pcm_hw_params_t *hw_params; const char* device_name = "hw:0,0"; // open audio device err = snd_pcm_open(&pcm, device_name, SND_PCM

问题 So i have a firebase database and this is my code to get specific data db = firebase.database() test = db.child("Users").order_by_child("IDNumber").equal_to(222333123).get().val() print(test) then the result returns as an OrderedDict OrderedDict([('Ays', {'Ays': 'Baby', 'IDNumber': 222333123})]) i want to extract the data and have Ays = Baby and IDNumber = 222333123 as two separate variables. i tried using .items() and putting it into list but i can't seem to separate it. is there any other

问题 So i have a firebase database and this is my code to get specific data db = firebase.database() test = db.child("Users").order_by_child("IDNumber").equal_to(222333123).get().val() print(test) then the result returns as an OrderedDict OrderedDict([('Ays', {'Ays': 'Baby', 'IDNumber': 222333123})]) i want to extract the data and have Ays = Baby and IDNumber = 222333123 as two separate variables. i tried using .items() and putting it into list but i can't seem to separate it. is there any other

问题 I have a problem with automatic running of service. I would like to run a script after user login. Once I have succeeded, however when I tried to automatize it, I'm getting an error and I can't find a mistake. Service: Description=Service desc [Service] Type=oneshot Environment=DISPLAY=:0.0 Environment=XAUTHORITY=/home/albert/.Xauthority Environment=HOME=/home/albert/ User=albert Group=albert RemainAfterExit=true StandardOutput=journal ExecStart=/home/albert/.startup-script.sh [Install]

问题 I used hostapd, dnsmasq and apache2 for implementing the wifi-hotspot with captive portal on my Raspberry Pi 3B+, before I implement this project, I have never get in touch with wifi networks. Hence I search a lot of post on how to implement one. Below is the configuration I used: /etc/apache/apache.conf: # Apple RewriteEngine on RewriteCond %{HTTP_USER_AGENT} ^CaptiveNetworkSupport(.*)$ [NC] RewriteCond %{HTTP_HOST} !^192.168.0.200$ RewriteRule ^(.*)$ http://192.168.0.200/index.html [L,R=302

问题 I used hostapd, dnsmasq and apache2 for implementing the wifi-hotspot with captive portal on my Raspberry Pi 3B+, before I implement this project, I have never get in touch with wifi networks. Hence I search a lot of post on how to implement one. Below is the configuration I used: /etc/apache/apache.conf: # Apple RewriteEngine on RewriteCond %{HTTP_USER_AGENT} ^CaptiveNetworkSupport(.*)$ [NC] RewriteCond %{HTTP_HOST} !^192.168.0.200$ RewriteRule ^(.*)$ http://192.168.0.200/index.html [L,R=302

问题 I have a Bluetooth LE Remote which I would like to pair with my Raspberry Pi Zero. ] I was able to successfully pair the remote with an Android phone and it then worked like a Keyboard and I was able to type numbers on the keypad into a blank note and even change the volume on the phone. It seems raspbian does not support HID over Gatt, which means that I need to implement/mimic a minimal HID over GATT behaviour using python. (Please correct me if there is a more straight-forward way to do

问题 I have a Bluetooth LE Remote which I would like to pair with my Raspberry Pi Zero. ] I was able to successfully pair the remote with an Android phone and it then worked like a Keyboard and I was able to type numbers on the keypad into a blank note and even change the volume on the phone. It seems raspbian does not support HID over Gatt, which means that I need to implement/mimic a minimal HID over GATT behaviour using python. (Please correct me if there is a more straight-forward way to do

问题 I have a Bluetooth LE Remote which I would like to pair with my Raspberry Pi Zero. ] I was able to successfully pair the remote with an Android phone and it then worked like a Keyboard and I was able to type numbers on the keypad into a blank note and even change the volume on the phone. It seems raspbian does not support HID over Gatt, which means that I need to implement/mimic a minimal HID over GATT behaviour using python. (Please correct me if there is a more straight-forward way to do