Module question

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jmendoza
Posts: 122
Joined: 18 Feb 2018, 23:07

Module question

Post by jmendoza » 08 May 2020, 06:04

Hi Phil,
I have a question for you:

Do the JP4IN1 and other multiprotocol modules require a PPM input to be able to bind a receiver?
And does that also apply to the Orange DSM modules too?

I have a JP4IN1 here fired up with 6 volts , no PPM input and noticed that my receivers will not bind to it. The RF module section is not getting warm either. I have 6 of these modules and they are all acting the same. If I had an open source Tx, I would use it to test the module. Guess I'll have to build up an Arduino with your 7 channel V2 sketch and connect it to the module, but wanted to ask you before I went to all that trouble. BTW, I did all the firmware updates using the latest version of the PPM firmware.

Thanks in advance for any guidance and responses.
Jay

Mike_K
Posts: 346
Joined: 16 Feb 2018, 06:35

Re: Module question

Post by Mike_K » 08 May 2020, 08:08

Maybe I can answer on behalf of Phil.

Yes you need a valid PPM signal for both of them to bind. Or a valid serial signal for the 4-in-1 in serial mode. In fact the OrangeRx modules will not give their familiar "confirmation beep" at startup without a ppm signal.

Another thing that might be worth fitting is a Schottky diode to the ppm input as looking at the circuit diagram, the 4-in-1 modules have only a 2K resistor, they assume it's being plugged into a FrSky (or Jumper) module bay with 3.3V signal level, when though they're described for JR.

And the last couple of 4-in-1 modules I've bought (cheapest no brand on Banggood) weren't flashed from the factory, so I had to flash them. The Jumpers and iRangers have all been flashed though.

But once up and running, they all work very well.

Mike

jmendoza
Posts: 122
Joined: 18 Feb 2018, 23:07

Re: Module question

Post by jmendoza » 10 May 2020, 16:16

Thanks Mike. The modules I got were not from Bangood, they were RadioBoss and HobbyPorter.
I could not flash them even though I downloaded the correct Maple drivers. Turns out there was a place on the board for a 3 pin header(Gnd, 3V3, Boot) I had to jumper 3V3 to Boot and bingo, they then uploaded the firmware I was trying to flash. I had to remove the jumper afterwards. All kinds of other issues with the instructions and the table it had for the PPM protocols. Turns out there were 8 DSM protocols, 4 of which were apparently redundant copies as the table did not define as to why they were repeated. Well, it is because 4 of them were for 6 channel, the other 4 were for 8 channel.

Can I use the Schottky diode I remove from the Pro Mini Strong board ( Vcc mod for module power) inline with the PPM signal?

My other question is these modules have a Vcc range of 5 to 7 volts, so should I not do the Vcc mod to the Pro Mini and instead let the module rum off the Mini's 5 volt V reg output?

Thanks Mike, and Phil, you guys are so helpful,
Jay

bluejets
Posts: 55
Joined: 19 Jun 2019, 04:09

Re: Module question

Post by bluejets » 11 May 2020, 09:57

Pro mini regulators are normally rather low current handling capacity (150mA odd)

Mike_K
Posts: 346
Joined: 16 Feb 2018, 06:35

Re: Module question

Post by Mike_K » 12 May 2020, 08:41

Hi Jay

As Bluejets suggests, I think an Arduino Pro Mini 5V voltage regulator is marginal for powering a module, most are either rated at 100mA or 150mA, the modules take a bit less than 100mA if I remember correctly.

I hadn't noticed the working voltage range of most 4 in 1 modules and powered my Jumper straight off a 2S Lipo and it's worked OK over about 3 months and 50 odd flights and hours on the bench. So you may get away with powering straight off a Lipo. As it worked OK I've done the same with all my other 4 in 1 modules without issue

I don't know what battery you are planning to use, but if it's a 2S Lipo and your worried about exceeding the 7.0V specification, maybe just fit a couple of diodes in series in the battery lead, something like 1N4148 each have around 0.7V drop x2 to give 1.4V drop, keeping you in the 5V to 7V range. But I must stress I haven't tried this.

Mike

Pchristy
Posts: 128
Joined: 16 Feb 2018, 13:57
Location: South Devon, UK

Re: Module question

Post by Pchristy » 13 May 2020, 08:04

Re: Batteries and voltage

Alternatively, a 2S LiFe will deliver 6.6V, with all the advantages of a LiPo and few of the disadvantages!

--
Pete

Mike_K
Posts: 346
Joined: 16 Feb 2018, 06:35

Re: Module question

Post by Mike_K » 13 May 2020, 22:23

Hi Jay

I've seen the 4-in-1 module specification saying working voltage 5-7V, but I was a bit suspicious that one Chinese vendor mistakenly put this in their specification and the others copied it. The modules use open-source hardware as well as open-source software, so I thought I'd take a look at the circuit and it clearly shows the voltage regulator Vcc being 12V max.

https://raw.githubusercontent.com/pasca ... B_v0.1.png

There is also a BOM and the voltage regulator is an AMS1117-50. These are rated to 15V absolute max, so using Vcc as 12V max is quite sensible. Assuming the modules have followed the open-source hardware then you should be OK with a 2S lipo or as Pete Christy suggests using a 2S LiFe.

https://github.com/pascallanger/DIY-Mul ... hematic.md

In fact, the AMS1117-50 has a drop out voltage of 1V, so it needs a minimum Vcc of 6V, so the last thing you want to do is power it with 5V.

But some manufacturers may not have followed the open-source circuit and used a different voltage regulator, but I can't believe any linear regulator would be rated 5-7V. And switch-mode regulators cost more, so they wouldn't use them. Get a magnifying glass out and see what voltage regulator your modules use, then you can be confident of using a higher voltage supply.

Mike

User avatar
F2B
Posts: 140
Joined: 16 Feb 2018, 11:23
Location: 20 m NE of Amsterdam

Finally: It's there!

Post by F2B » 14 May 2020, 19:14

:D :mrgreen: :D
Yesss!!!!!!!!!
Image
Image
F2B or not to be....

MaxZ
Posts: 194
Joined: 31 Jan 2019, 11:48
Location: Boskoop, Netherlands

Re: Module question

Post by MaxZ » 14 May 2020, 21:40

Wish we could see it too........... :(

Mike_K
Posts: 346
Joined: 16 Feb 2018, 06:35

Re: Module question

Post by Mike_K » 15 May 2020, 09:48

Phil_G wrote:
14 May 2020, 23:52

Re the Multimodule voltage, remember its not just the regulator, which as Mike has said is fine on 12v, its also the working voltage of the input tantalums, 8 volts for example is a standard, if they used 8v tants then the conservative spec could be right.
I only checked the suggested capacitor in front of the 5V regulator (C3) and on the open-source hardware it is a 22uF Tantalum 16V, as it is on my Jumper and iRanger, so the manufacturers who put their names on their products are fine at 12V. As I've said I've had lots of flights with my Jumper 4-in-1 module and hours with it powered up on my bench on a 2S lipo and it's been fine.

Good news that FrSky is getting nearer to release their XHT, I wonder when they will actually be available from T9 or similar distributor?

And has anybody who ordered their DHT from Hobby King received them yet? My tracking still shows it's stuck in Singapore, with the message saying due to lack of transport! I thought there were about 20,000 spare aircraft around the world at the moment! I guess there is probably a shortage of transport aircraft. How long before we try to claim off Hobby King or our credit card?

Cheers

Mike

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