Posts: 1,367 Threads: 118 Likes Received: 1,411 in 728 posts Likes Given: 1,070 Joined: Jun 2019 Reputation: 41 16-Jun-2020, 06:51 AM (This post was last modified: 16-Jun-2020, 06:51 AM by ph2t.) Found this titbit today whilst flashing a new FC I have. I wanted to update to BF4.2 and an appropriate bidirectional dshot version of bl_heli_S. The official notes for BF4.2 say: https://github.com/betaflight/betaflight...RPM-Filter Quote:[/url]Recent Announcements- WARNING! - Avoid any unofficial beta BLHeli_S firmware versions from JazzMaverick labeled 16.8, 16.9, or later as they are incompatible with RPM Filtering. The author made undesirable changes that reduce the rate at which RPM telemetry data is supplied. As a result the RPM filtering will not track the motor vibrations well, resulting in poor filtering performance and possibly hotter motors. The 16.73 version is the only recommended version that properly supports RPM filtering.
- Bidirectional DSHOT and RPM Filter for BLHeli_S escs. Free Version. Install the latest BLHeli Configurator and [b](choose firmware version 16.73)[/b] [url=https://github.com/blheli-configurator/blheli-configurator/releases/latest]Get it here!
- Latest EA of a custom BF 4.1 Performance Edition for F3 FCs available. Get it here!
- JESC supports bidirectional DSHOT and RPM Filter on BLHeli_S escs. Free on L ESCs, Paid but VERY cheap and worth it on H ESCs! 48khz and 96khz PWM version available for testing Get it here!
- Bidirectional DSHOT now fully supported in the just released version 32.7.0 of blheli32. You can flash from configurator without downloading hex files manually.
Note the first point about the JM firmware, I didn't know this. I've played around with some later versions I think on my whoop and 1S toothpick, the 16.8 and possibly the 16.9., Maybe I was just going for the higher PWM freqs and not doing bidirectional dshot, can't remember. Still it pricked my ears enough to just stay with 16.73 for now. Has anyone has experience with bidirectional dshot failing with the later JM firmwares? cheers, ph2t. Posts: 1,312 Threads: 50 Likes Received: 832 in 504 posts Likes Given: 372 Joined: Jul 2018 Reputation: 51 From what I understand, JazzMac changed his firmware so that it returns RPM data every 10ms, instead of with every DSHOT packet. Betaflight said that wasn't enough to do RPM filtering properly and is against the design specifications. Jazz Maverick says it's plenty. You can read the details of the bust-up on RC Groups from here onwards: https://www.rcgroups.com/forums/showthre...lk/page422 Now it looks like JazzMac has decided to make his own firmware, with blackjack and hookers. https://www.rcgroups.com/forums/showthre...ck-version Honestly, does anyone really care about JESC/JazzMaverick beyond RPM filtering, and maybe 48kHz PWM for micros? Breaking RPM filtering seems like a bold move.
The ground is for dead people. ![[-]](https://intofpv.com/images/collapse.png) • Posts: 21,195 Threads: 583 Likes Received: 8,935 in 6,610 posts Likes Given: 1,425 Joined: Jun 2018 Reputation: 786 The Betaflight devs and Jazz Maverick have been a loggerheads for some time now which I guess is why they put that disclaimer in the release notes. I was originally running the Jazz Maverick 16.8 48KHz firmware on both my UK65 and Trashcan without any noticeable issues, but after reading the  storm over on RCG I decided to switch to the JESC 48KHz firmware instead and just pay up for it. More for peace of mind than anything else. I made some comments about it in the following threads/posts... https://intofpv.com/t-has-anyone-here-tr...5#pid93835 https://intofpv.com/t-eachine-trashcan-7...5#pid95325 • Posts: 92 Threads: 5 Likes Received: 30 in 23 posts Likes Given: 77 Joined: Oct 2019 Reputation: 1 04-Jul-2020, 12:29 PM (This post was last modified: 15-Jul-2020, 07:36 AM by santi_p.) This is what happens in my GT R 349 with BF 4.1.6 + JazzMav BLHeli_S 16.80 (audio required)
It took me some time to figure it out but after reading Snow's post I rolled back to 16.73 and now it's ok even with BF 4.2
Now that I know what can happen, I'll go for JESC firmware
I have to say that I've flown this little thing with that configuration and it was ok, only started to worry when landings became almost impossible. I was lucky this day my wife was spotting and had decided to record some video
Edit: Problem still there, so not directly related
Santi • Posts: 12,099 Threads: 125 Likes Received: 3,739 in 2,836 posts Likes Given: 99 Joined: Feb 2017 Reputation: 388 Am I correct that Jazz Maverick 16.9 (aka blheli_M) is now compatible with BF RPM filtering again? https://www.rcgroups.com/forums/showthre...ck-version • Posts: 1,367 Threads: 118 Likes Received: 1,411 in 728 posts Likes Given: 1,070 Joined: Jun 2019 Reputation: 41 According to the author the sampling rate is the same on versions above 16.73 - the contention is JM states you only need a sample rate of 7 per second whilst BF requires 42 samples/second. I think that was the core of the sh1tshow that happened. • Posts: 1,312 Threads: 50 Likes Received: 832 in 504 posts Likes Given: 372 Joined: Jul 2018 Reputation: 51 I had a quick look through the thread and it seems like he started returning data with every packet and more recent versions sample at the full rate, but only at lower RPM.
With 96kHz and "Commutation Enhancement" it really seems like JazzMac is focusing on efficiency for micros with bidirectional as an afterthought.
The ground is for dead people. Posts: 12,099 Threads: 125 Likes Received: 3,739 in 2,836 posts Likes Given: 99 Joined: Feb 2017 Reputation: 388 (30-Jul-2020, 06:56 AM)ph2t Wrote: According to the author the sampling rate is the same on versions above 16.73 - the contention is JM states you only need a sample rate of 7 per second whilst BF requires 42 samples/second. I think that was the core of the sh1tshow that happened. In the first paragraph of the thread, JM said 42 sample/revolution. It this the same as the 42 samples/second you mentioned? • Posts: 1,367 Threads: 118 Likes Received: 1,411 in 728 posts Likes Given: 1,070 Joined: Jun 2019 Reputation: 41 30-Jul-2020, 11:48 AM (This post was last modified: 30-Jul-2020, 11:48 AM by ph2t.) (30-Jul-2020, 09:59 AM)voodoo614 Wrote: In the first paragraph of the thread, JM said 42 sample/revolution. It this the same as the 42 samples/second you mentioned? Yes I believe so, I recently joined the bf Facebook group and saw it mentioned there I think. Sorry for no reference- I’ll try and find it. • Posts: 1,367 Threads: 118 Likes Received: 1,411 in 728 posts Likes Given: 1,070 Joined: Jun 2019 Reputation: 41 The post was made by a don Thomas in the fb group on July 10. I can’t link a screenshot right now as my phones picture is too large. I’ll post the ref once I’m in front of a pc again.
But yes 16.9 RC4 has the same sampling rate of 42 times just like 16.73. • Posts: 12,099 Threads: 125 Likes Received: 3,739 in 2,836 posts Likes Given: 99 Joined: Feb 2017 Reputation: 388 If you switch to full version mode for this website, you can use the IMGUR option to post a photo. It will scale any photo down to size. • |
