H's Blog

I was able to transmit video using ADALM PLUTO and DATV Express to a Satellite receiver. ADALM PLUTO is modified to transmit up to 6GHz. The software I used are DATV Express and vMix Basic. They are both free. DATV Express is beta so use at your own risk. The laptop is Acer Aspire Timeline X Core i7 with 8GB RAM. The receiver is a cheap DVB-S2 receiver from China. Nothing fancy. I cannot find any brand name or model number. I will not be able to upgrade to a newer firmware. I bought it for $21 from eBay. The wifi dongle came broken. That does not affect our project. But with wifi dongle, I can watch YouTube from this little box. The replacement is on the way from China. The antenna did not come with it. I borrowed one from USB TV tuner I had. This is the exact model as shown in these videos. https://www.youtube.com/watch?v=qknWQi54oCo https://www.youtube.com/watch?v=m290NR5pEfY&t=1121s Since I've never used satellite receiver before, finding the right settings for...

I was able to fix the video problem. I needed to add -thread_queue_size 1024 after -f alsa :~/gr-dvbt$ ffmpeg -re -thread_queue_size 1024 -i /dev/video0 -vcodec mpeg2video -f alsa -thread_queue_size 1024 -i hw:0,0 -acodec mp2 -s 320x240 -r 60 -b:v 2M -minrate:v 2M -maxrate:v 2M -bufsize:v 14M -ac 2 -b:a 48k -mpegts_transport_stream_id 1025 -mpegts_service_id 1 -mpegts_pmt_start_pid 0x0fff -mpegts_start_pid 0x0121  -muxrate 4524064 -f mpegts -y in.fifo Now the video is very smooth. Also, you can add your call sign.  ffmpeg -re -thread_queue_size 1024 -i /dev/video0 -vcodec mpeg2video -f alsa -thread_queue_size 1024 -i hw:0,0 -acodec mp2 -s 320x240 -r 60 -b:v 2M -minrate:v 2M -maxrate:v 2M -bufsize:v 14M -ac 2 -b:a 48k -mpegts_transport_stream_id 1025 -mpegts_service_id 1 -mpegts_pmt_start_pid 0x0fff -mpegts_start_pid 0x0121  -muxrate 4524064 -f mpegts -vf drawtext=fontfile=/usr/share/ fonts/truetype/freefont/ FreeSerif.ttf:text="CALLSIGN":x= 440:y=420:...

I just got my HackRF and was playing with it ever since. One of my interests is Digital Amateur TV. I was searching for solutions to do DATV using HackRF. Finally, I was able to test transmitting video via HackRF. I followed the following 2 sites and modified commands and dvbt-hackrf.py. 1. http://photohamrad.blogspot.com/2015/06/transmitting-video-with-hackrf-blue.html 2. https://irrational.net/2014/03/02/digital-atv/ I only tested on 441MHz. I will need to tweak on ffmpeg switches and python code to make the video smoother. Right now the video only shows the initial image and no movement. avconv may be better but I was not able to install it, so I used ffmpeg. My next challenge is to transmit in DVB-S2 and receive the video with Satellite set-top receiver. So far, I am not able to build dvb-s package. I also ordered Adalm Pluto from Arrow Electronics but they have not shipped it. Environment: Transmitter PC Lenovo ThinkPad X201 Core i5 CPU 4GB RAM Ubuntu Mate 18.04 H...

I was able to install macOS High Sierra on my Lenovo X220 8GB RAM 320GB HD by following this site. http://x220.mcdonnelltech.com/ The performance is pretty good. I am writing this blog on the X220 running High Sierra. The only issues I had were: 1. Left mouse button causes double click - by using extra USB mouse, the problem can be avoided, or by turning off touchpad 2. Wifi - wifi card in the laptop does not work. - By using TP-Link TL-WN823N V2 with the macOS 10.12 driver on their support site, the Wifi started working. Wired ethernet port works fine without any modification. https://www.tp-link.com/us/download/TL-WN823N.html#Driver I installed Xcode,  Android Studio, Cubase Element 8, and VMWare Fusion. I needed to enable VT-D in BIOS to be able to run VMs. I installed Linux Mint and Windows 7 successfully. However, I am having a problem that VMs cannot get IPs from my DHCP server. Static IPs work fine. It could be my router at fault. I ordered a newer and faster route...