Yet another Single Channel Encoder

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Mike_K
Posts: 577
Joined: 16 Feb 2018, 06:35
Location: Hertfordshire

Re: Yet another Single Channel Encoder

Post by Mike_K »

Hi John

The "quick-blip" throttle control is on line #370:

if (scCompound == 7 && digitalRead(scSwitch) == 1 && codaLatch == 0) {

change the scCompound == 7 to a lower value - eg if (scCompound == 5 && digitalRead(scSwitch) == 1 && codaLatch == 0) {

The "quick-blip" is set a bit later than on a real Elmic escapement, the program splits the rotation into "40 segments", so each segment = 360deg/40 = 9deg per segment and 7*9 = 63deg rotation, the real Elmic has it nearer 45deg if I remember correctly. It was set longer as I had trouble operating the throttle, my thumb just couldn't blip quick enough to change the motor speed.

Also the emulation is slightly slower than Phil_G S/C emulator, this encoder has 40*20mS = 800mS or 0.8secs for a "rotation", I think Phil's is 32*20mS = 640mS or 0.64secs. Doesn't sound like much of a time difference, but I know some struggle to adapt between the two. I think Phil must have timed a fully wound escapement, me an escapement that had wound down a bit!

Cheers

Mike

sc_03K_blip_throttle.jpg
John Ryan
Posts: 21
Joined: 31 Mar 2021, 03:56
Location: Rotorua New Zealand

Re: Yet another Single Channel Encoder

Post by John Ryan »

Hi Mike
Thanks again. I did some experimenting using values of 4, 5 & 6. 5 works perfectely for my thumb! Was flying the Mlls 75 Simplex again yesterday and had the guys asking what all the beeping was all about. I'll be silent now!

Regards
John
MaxZ
Posts: 318
Joined: 31 Jan 2019, 11:48
Location: Boskoop, Netherlands

Re: Yet another Single Channel Encoder

Post by MaxZ »

Hi Mike,

Finally, I have gotten around to configure my S/C Tx, built to your Single_Channel_03K sketch, to match the settings on my regular propo Tx which I used to tame my Tomboy when flown "bang-bang" style. In the course of this I found two items I'd like to share with you.

First, I got confused when I tried to change the channel order from RETS to TRES, mainly because I had replaced the jumpers setting the various configs with a set of micro switches, but had forgotten in which order these needed to be set as per your table in the instructions. My fault, but it highlighted a tiny, tiny mistake in the sketch comments: line 636 should read 0 - RETS, 1 - TRES. No further consequences for the manual as I can see.

Further, I found that, when you set the sub trims for rudder and elevator first, and adjust the travel next, the endpoint pulse length shown during configuration does not match the net result in operation mode, as it does not incorporate the changed mid point pulse. A small nuisance when you are aiming for a particular deflection of, say, your elevator control surface, but a few iterations will get you there. Or do the travel adjustment first, then the sub trim adjustment. I did a pulse for pulse comparison with my other tranny, so that is why I stumbled upon this.

All this detracts nothing from my admiration for you work here Mike, happy as before.

Cheers,
Max.
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Phil_G
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Re: Yet another Single Channel Encoder

Post by Phil_G »

Mike_K wrote: 14 Feb 2022, 20:31 Also the emulation is slightly slower than Phil_G S/C emulator, this encoder has 40*20mS = 800mS or 0.8secs for a "rotation", I think Phil's is 32*20mS = 640mS or 0.64secs. Doesn't sound like much of a time difference, but I know some struggle to adapt between the two. I think Phil must have timed a fully wound escapement, me an escapement that had wound down a bit!
My own PIC S/C emulation encoder is unchanged over 12 years now, 28 steps at 18ms frame rate, uses Rex Boyer's timing from an Elmic Commander review in an old mag :D It is quite a bit faster than Mikes, and fits my recollection of escapement flying, but not fast enough for Pete who uses Compacts with the lightest rattler - I did a faster 24-step version for Pete and also added the faster speed into the 7ch+S/C encoder as a switchable compile option.
The 'normal' 28 or 'fast' 24 step cycle is a dipswitch option in the Single Channel Emulation NRF24 FHSS project which is a really cheap way to make a modern reliable S/C outfit :D
[Sorry I know I'm hopping onto Mikes thread but I dont think he'll mind, if anyone wants one of the PIC S/C Emulation Encoders (as an alternative to Mikes or Martin's) I've over a hundred PCBs and PICs to hand, Stu's Lemon DIY modules suit it perfectly]
Cheers
Phil
Pchristy
Posts: 332
Joined: 16 Feb 2018, 13:57
Location: South Devon, UK

Re: Yet another Single Channel Encoder

Post by Pchristy »

Phil_G wrote: 17 Jul 2022, 13:53 ...but not fast enough for Pete who uses Compacts with the lightest rattler - I did a faster 24-step version for Pete and also added the faster speed into the 7ch+S/C encoder as a switchable compile option.
The 'normal' 28 or 'fast' 24 step cycle is a dipswitch option in the Single Channel Emulation NRF24 FHSS project
Yes, I never had a Commander, going straight from a Conquest (sequential, which I never got on with!) to a Compact. Since it was going in a Sharkface, I opted for the "fast" rattler and have used one ever since!

When I finally got a Commander, I found I could never get "left" with it, as I was pressing twice before it reached "right"! I also had weird issues with Phil's PIC emulators that sat in line between an Old School s/c receiver and a servo. Phil kindly provided a speeded up version for me, which works just fine!

For an original i/c powered Sharky, you need a FAST acting servo or escapement! :lol:

--
Pete
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Shaun
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Location: West Yorkshire

Re: Yet another Single Channel Encoder

Post by Shaun »

I was a fan of the Compact especially as you could have kick up (or down) elevator. I always put kick down on my slope soarers.

Shaun.
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Mike_K
Posts: 577
Joined: 16 Feb 2018, 06:35
Location: Hertfordshire

Re: Yet another Single Channel Encoder

Post by Mike_K »

Hi Max
MaxZ wrote: 17 Jul 2022, 12:35 Further, I found that, when you set the sub trims for rudder and elevator first, and adjust the travel next, the endpoint pulse length shown during configuration does not match the net result in operation mode, as it does not incorporate the changed mid point pulse. A small nuisance when you are aiming for a particular deflection of, say, your elevator control surface, but a few iterations will get you there. Or do the travel adjustment first, then the sub trim adjustment. I did a pulse for pulse comparison with my other tranny, so that is why I stumbled upon this.
Sorry for the slow response, I've been busy with other projects (non R/C) and have given the forum a rest for a week or two and then I wanted to look at the code before answering. I can see what I've done and can see what you'd prefer and it should be possible to modify the code, it's how the sub-trim and end-points work on my multi-model memory propo encoder, so it's just a case of copy, paste and integrate. I can't promise the update anytime soon, but I'll put them on the to-do list. And I'm pleased you're happy with the encoder, it's what makes it worth publishing.
Phil_G wrote: 17 Jul 2022, 13:53 My own PIC S/C emulation encoder is unchanged over 12 years now, 28 steps at 18ms frame rate, uses Rex Boyer's timing from an Elmic Commander review in an old mag :D It is quite a bit faster than Mikes, and fits my recollection of escapement flying, but not fast enough for Pete who uses Compacts with the lightest rattler - I did a faster 24-step version for Pete and also added the faster speed into the 7ch+S/C encoder as a switchable compile option.
Thanks, Phil for sharing your timings, I've never had one of your S/C encoders to see the actual timings and I assumed it was the same your 7-channel encoder (28 steps @ 20mS). The timing of escapements is not an exact science, the commander goes considerably faster fully wound, than when near unwound, I know because I timed both fully wound and unwound with various points in between. To get to the speed Pete uses, I would need a lot of winds and the escapement would often "skip" past the pawl and rotate uncontrolled, but I probably had a worn-out badly adjusted escapement! The good news is it's fairly trivial to alter the program timing using the number of steps (as long as they're multiples of 4) and a different frame rate. Most 2.4GHz modules will happily work with any frame rate, as long as the sync-pulse is an adequate length, so it would be possible to have the frame rate and the number of steps as definitions at the start of the program, so you could choose what escapement timing you wanted when you compile it eg 28 steps * 18mS = 504mS or alternatively say 24 steps at 22mS = 528mS for a fractionally slower rotation. The only problem I see is the blip throttle and kick-up elevator timing may become critical, but I'm certain it's doable. Again I'll add it to the to-do list.

Cheers

Mike
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Phil_G
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Re: Yet another Single Channel Encoder

Post by Phil_G »

Hi Mike, Max - sorry I shouldnt have interrupted your thread especially in the middle of a tech-support session Image
My apologies
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