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Blue Blocker status

After testing a half dozen recievers, I noticed that none of them followed the 1960 video specification. They all have a different bias voltage, one even goes negative with respect to ground. One receiver was close enough to work, the others I was able rebias through a potentiometer. The fix is to measure the offset with an ADC, then rebias the signal using a voltage from a DAC. Unfortunately the G071 chip I am using only has 2 DAC outputs, one is needed set the comparator voltage, and the other is needed as a voltage limiter. I could include a reciever module or port the OSD to a different chip, but I only allocated 1 month for this project. I am not sure I want to extend this project, like I did for the OSD project. I ended up designing a flight controller to support the OSD. Anyways I am pausing this project for now. The alpha boards work, but I need to add a comparator to regain video sync after it is lost. As it is now, if video sync is lost for over a few seconds, it wil
Recent posts

Introducing Blue Blocker

I decided the garage needed a bigger TV. The 22" one I fly on is just too small for content consumption. The only issue is most TVs blue screen on the slightest hint of interference causing your drone to crash BSOD style. Blue Blocker solves this problem by conditioning the video signal before it is sent to the TV. Product under development, beta boards due Monday, ETA for a release candidate board in my hand from a pick and place fab, early to mid December. (time permitting) Thanks to OSH Park for the free 5 day quick turn upgrade on the beta pcb fab.

1 Year Update

Its been a year since I started this OSD project, or 6 months since I stopped, and I want to give an update on what happened along the way. When I started I thought an open sourced OSD with graphics would generate a lot of interest in the betaflight community. I saw it as low hanging fruit that could be done rather cheap and quick, but I misjudged the interest. This cause me to make certain software design decisions that in retrospect, I should not have made. The software mixes 2 display layers in realtime, one for text, and another for graphics. This barely fits on a M0+ and required some creative optimizations to work as it runs a 15K IRQ/second line rate. A single layer approach is around 70% nops, so I wanted to do something useful with those cycles, the 2 layer display was born. This ends up causing minor tearing (1-2 pixel) when betaflight sends SPI commands. This could be overcome if commands are sent during a VBI so I have a pin go low, but this would require a betafli

TexHex OSD Video

Here is a new Video of the OSD on the TexHex Flight Controller.
It's been awhile since my last post... The OSD and FC works great.   It flies well, is validated, designed for manufacture, and its schematic is available on this site.   But I paused its development/manufacture in early March.   I did not want to make the 2000 or so it would take to be price competitive to sell at hobby stores nor does selling only on this website seems feasible, not enough traffic.  In March, I was unsure how Covid 19 was going to play out, but I knew the 2 now 3 trillion in stimulus (or 15% GDP) was going to be a big money grab for the rich and well connected.  (209 million adults in US * $1200 stimulus check = 8.3% of 3 trillion)  A few months later and the shelter in place order is finally starting to lift, unemployment is very high,  riots on the streets because the police have no rules of engagement and are allowed to use tactics that lead to permanent brain damage or death in this case.  And an official Covid 19 death toll of over 100,000, that is likely un

Second Beta Build at fab.

I sent the files for the second beta version to the fab. I found and fixed 8 issues with beta 1. I also squished all the parts as close together as possible, It looks like this design could fit on a 4 layer 20x20mm board in the future. This one should be very close to a release candidate. ETA is March 28, a delay was added due to covid-19 virus. I am considering making a prototype test jig for this revision in the meantime. I need an easy way program and test boards before they are shipped to provide some QC. A second PCB with spring loaded pogo pins in a 3-D printed jig is what I have in mind. Since my 3-D printer has a resolution of .2mm I had to make sure my pads on the PCB are also centered at .2mm.

FC1 Beta Bring Up

I have had my beta boards for a couple of days, a few issues need to be addressed and tested then onto alpha board design and build. The worst issue of the beta boards was the BMP280 barometer package pins were mirrored as it is the only chip I know of that pin one is in the upper right corner. Assuming pin 1 was upper left resulted in a short to ground and the chip needed to be removed. I expect these sort of problems for a beta board, so hopefully the upcoming alpha board will be very close to a release candidate.