Home  |  Contents 

Microcontroller and PC projects
  Forum Index : Microcontroller and PC projects         Section
Subject Topic: HC-12 old vs new module.... Post ReplyPost New Topic
Page of 12 Next >>
Author
Message << Prev Topic | Next Topic >>
Grogster
Guru
Guru
Avatar

Joined: 31 December 2012
Location: New Zealand
Online Status: Offline
Posts: 5960
Posted: 17 April 2018 at 3:39pm | IP Logged Quote Grogster

I spent most of today, tearing my hair out trying to work out why the hell HC-12's that I have used so many of in the past, would not talk to each other.

If you have two of the older model, they talk fine.
If you have two of the newer model, they talk fine.

If you have one old one and one new one, they DON'T. You will get some messages, but more then 50% of transmissions are ignored by the receiving end. I have no idea why that should be. Triple checked all connections, configuration etc, but if you have one old and one new, they are f-ing hopeless together.

I can configure both with Rob's HC-12 tool, and they both read and write the config just fine, but when you put them online to actually talk to each other, the performance is appalling.

As soon as I put an identical one from my new batch with the thing I was trying to get going(which used the exact same module), it sprung to life with 100% message reliabilty as I have come to expect from the HC-12 modules.

Looking at the modules up close, they appear to be identical electronically, but there is a silkscreen difference with the newer ones over the older ones:







The module with the helical fitted is the OLD one. Note that the newer one has the website on the bottom silkscreen.

The only thing I can think of is that in the newer ones, they have changed something in the code for the on-board MCU, with respect to the way that it talks to the RF chip or something - it makes no sense to me. Has anyone else seen this with their HC-12's?

As I say, not a problem if BOTH(or more) are all the same one, but if you mix them, the results are terrible - even though all the settings are identical.


__________________
Smoke makes things work. When the smoke gets out, it stops!


Back to Top View Grogster's Profile Search for other posts by Grogster Visit Grogster's Homepage
 
Azure
Guru
Guru
Avatar

Joined: 09 November 2017
Location: Australia
Online Status: Offline
Posts: 362
Posted: 17 April 2018 at 3:46pm | IP Logged Quote Azure

Just to clarify the setup:

You have a new module with no antenna (helicoil) trying to connect to an old module with an antenna (helicoil).

What antenna configurations have you tried to get them to talk to each other on either/both modules?

Back to Top View Azure's Profile Search for other posts by Azure
 
Grogster
Guru
Guru
Avatar

Joined: 31 December 2012
Location: New Zealand
Online Status: Offline
Posts: 5960
Posted: 17 April 2018 at 3:55pm | IP Logged Quote Grogster

No, both have helicals. I just left the helical on the old one, so you can easily see the difference between the two in the photos.

Here are close-up shots of the MCU's, which do appear to be a different part number:

OLD HC-12 MCU:





NEW HC-12 MCU:




It is possible I am on the wrong track here - I don't really know my ST part numbers, so it might just be an equivalent part.

EDIT: I take that back - they both seem the same. The ST part number would appear to be the 2nd line, not the first one. Both 2nd lines match, so I expect that is the actual MCU part number, meaning both modules are EXACTLY the same.

I need a large Whisky.....

Edited by Grogster on 17 April 2018 at 3:57pm


__________________
Smoke makes things work. When the smoke gets out, it stops!
Back to Top View Grogster's Profile Search for other posts by Grogster Visit Grogster's Homepage
 
Azure
Guru
Guru
Avatar

Joined: 09 November 2017
Location: Australia
Online Status: Offline
Posts: 362
Posted: 17 April 2018 at 4:52pm | IP Logged Quote Azure

This is the chip the bottom right is the date and revision code (page 93 in the manual).

So they are both rev Y of the same chip AFAICT (as far as I can tell).

Edited by Azure on 17 April 2018 at 4:53pm
Back to Top View Azure's Profile Search for other posts by Azure
 
CaptainBoing
Guru
Guru
Avatar

Joined: 07 September 2016
Location: United Kingdom
Online Status: Offline
Posts: 561
Posted: 17 April 2018 at 5:46pm | IP Logged Quote CaptainBoing

Hey Grogs.

How old are those ones without the URL on?

I ask because I just checked, all mine have it and I have used hundreds of the things over the past 3 years with no issues. I can't check those but all the ones I have in stock look like your top image.

This is kind of an earthquake for me and I sympathize with your predicament that you now have a situation where you might add something later that is incompatible... I use these in networks so there is a real possibility (of me adding something that might not work and I never thought to make a record of every one I used... I am even less inclined to arrange time with the customers to do a site survey... gawd!

I know it would be really tedious, but have you tried a mis-matched pair and gradually changing the channel number on one and re-checking each time, just in case they are interpreted differently... I suppose they are all the same band (433MHz)?

Edited by CaptainBoing on 17 April 2018 at 5:50pm
Back to Top View CaptainBoing's Profile Search for other posts by CaptainBoing
 
Grogster
Guru
Guru
Avatar

Joined: 31 December 2012
Location: New Zealand
Online Status: Offline
Posts: 5960
Posted: 17 April 2018 at 6:24pm | IP Logged Quote Grogster

"O Captain, my captain"....

What I might do tomorrow, is hook up both modules(set to same specs), and plonk them on the spectrum analyser and compare outputs. Both are running in same band, yes.
Exactly the same channel. Perhaps there is a frequency difference between the modules, although, I would have seriously doubted it.

The "Old" ones I have are very old. I probably got them from eBay about 8 years ago.
Luckily, I don't have many of those, and all my stock ones have all been the newer type with the website on the bottom silkscreen. I just did not think it mattered, as they were all the same. Or so I thought.

Edited by Grogster on 17 April 2018 at 6:25pm


__________________
Smoke makes things work. When the smoke gets out, it stops!
Back to Top View Grogster's Profile Search for other posts by Grogster Visit Grogster's Homepage
 
CaptainBoing
Guru
Guru
Avatar

Joined: 07 September 2016
Location: United Kingdom
Online Status: Offline
Posts: 561
Posted: 17 April 2018 at 9:02pm | IP Logged Quote CaptainBoing

Grogster wrote:
I just did not think it mattered, as they were all the same. Or so I thought.


Quite... and this follows hot on the heels of me trying to calm a fellow shedders fears about using them "yeah! what you put in one end just pops out the other end, you'll be fine"... I jinxed it really didn't I?
Back to Top View CaptainBoing's Profile Search for other posts by CaptainBoing
 
Grogster
Guru
Guru
Avatar

Joined: 31 December 2012
Location: New Zealand
Online Status: Offline
Posts: 5960
Posted: 18 April 2018 at 9:07am | IP Logged Quote Grogster

Test frequency: Channel 64.(458.6Mhz)

According to my UHF scanner:

NEW type module sitting on 458.637MHz
OLD type module sitting on 458.600MHz

Therefore, NEW one seems to have a 37kHz frequency difference to the older one when set to the same channel.

This is technically now out of licence here in NZ(458.54-458.61 @ 500mW SRD), but would explain why the old and new are not too happy about working together - although set to the same frequency, they are not technically on the same frequency, and if they are a narrow-band transmitter(as I expect they are), then this explains quite a bit as 37kHz off frequency would really stuff things up.

Pain in the arse.

Changing channel frequency won't help, as the channels are 400kHz apart, so moving down to channel 63(458.2MHz as set, but will really be 458.237MHz) is still outside of band too.

I will try a test by resetting the module back to 433MHz band, and see what the frequency error is there. Perhaps it is only in the upper channels or something - which won't help me, but.....

__________________
Smoke makes things work. When the smoke gets out, it stops!
Back to Top View Grogster's Profile Search for other posts by Grogster Visit Grogster's Homepage
 
Grogster
Guru
Guru
Avatar

Joined: 31 December 2012
Location: New Zealand
Online Status: Offline
Posts: 5960
Posted: 18 April 2018 at 9:43am | IP Logged Quote Grogster

Yup, the new ones are 37kHz out on the 433MHz band too.

I reset the new module to Channel 1(433.4MHz), and they are NOT there on 433.400MHz on the scanner, but they ARE there on 433.437MHz....

Configure an OLD one for Channel 1, and it is perfectly on frequency on 433.400MHz on the scanner. I could hook them to the spectrum analyser, but I expect it will tell me exactly the same thing as my UHF scanner is.

Both the old and the new one seem to use the same 30MHz oscillator module from what I can see, so in theory, if the 4461 Transceiver chip uses that as it's reference, then channel 1 should be exactly the same on both. I have downloaded the datasheet for the transceiver chip and am reading some of it now, but agughhhhh.....I don't have time for this.....

Here is a link to the 4461 chip PDF if anyone wants to read it.

__________________
Smoke makes things work. When the smoke gets out, it stops!
Back to Top View Grogster's Profile Search for other posts by Grogster Visit Grogster's Homepage
 
Azure
Guru
Guru
Avatar

Joined: 09 November 2017
Location: Australia
Online Status: Offline
Posts: 362
Posted: 18 April 2018 at 10:35am | IP Logged Quote Azure

Had a very quick run through the specs you linked and nothing obvious jumped out.

Do you have a close up of the two chip versions. Might be some chip revision stuff worth looking up.
Back to Top View Azure's Profile Search for other posts by Azure
 
Chopperp
Senior Member
Senior Member
Avatar

Joined: 03 January 2018
Location: Australia
Online Status: Offline
Posts: 237
Posted: 18 April 2018 at 10:48am | IP Logged Quote Chopperp

Quick Question(s)
Read whole heap of posts on these (HC-12) plus data sheet. Still bit confused.
Do these modules connect to the standard uMite COM 1/COM2 ports or are they SPI or something other?
Secondly, where's a good place to buy them?

Thanks

__________________
ChopperP
Back to Top View Chopperp's Profile Search for other posts by Chopperp
 
Grogster
Guru
Guru
Avatar

Joined: 31 December 2012
Location: New Zealand
Online Status: Offline
Posts: 5960
Posted: 18 April 2018 at 10:55am | IP Logged Quote Grogster

Both exactly the same part, that being "44631B" on the chip, which is a Si4463 revision 1B, so the RF chips are identical.

Looking at the datasheet, page 33 talks about setting the frequency synth, and so I suspect that in the latest version of the HC12 firmware(in the ST chip on the module), they have changed the stepping factor for setting the frequency, which would explain this issue.

To confirm this, I could swap the ST chips between the boards. If that is indeed the case, then that would make the NEW one behave if you see what I am getting at. Naturally, that is not a practical fix for the issue, but it would prove one way or another if the ST MCU is the problem here, and I now suspect that it is - it HAS to be, cos everything else is identical between the two different boards.

__________________
Smoke makes things work. When the smoke gets out, it stops!
Back to Top View Grogster's Profile Search for other posts by Grogster Visit Grogster's Homepage
 


Page of 12 Next >>
In the news...
 
Post ReplyPost New Topic
Printable version Printable version
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot delete your posts in this forum
You cannot edit your posts in this forum
You cannot create polls in this forum
You cannot vote in polls in this forum

Powered by Web Wiz Forums version 7.8
Copyright ©2001-2004 Web Wiz Guide

This page was generated in 0.1089 seconds.
Privacy Policy     Process times : 0, 0, 0, 0.11