Squelch open when battery under 7.0 V in DM-1801, etc.

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EA5JAQ
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Joined: Thu Jul 16, 2020 6:08 am

Squelch open when battery under 7.0 V in DM-1801, etc.

Post by EA5JAQ » Wed Dec 16, 2020 9:24 am

Hi Roger,

I noticed that when the battery is low (7.0 V and lower, around 37% battery in my case, and it’s strange because it doesn’t happen when voltage is 7.1 V), the squelch remains open after the end of a received transmission, independently of the level that has been set (and does other weird things, for example, when transmitting in FMN at 5W, i sometimes hear a loud beep when I release PTT and then a constant hiss sound, the speaker remains on but plays nothing). As battery level goes lower, this happens all the time, and the radio needs to be turned off and on to have the squelch back on again (but remains open whenever the radio receives another signal). This happens in another DM-1801 i could get my hands on, and both in the R2020.10.16 and D2020.11.12.01 versions.

Also, I noticed that in one of those two radios, the battery percentage (when it’s stable) is always around 0.1-0.2 V or 6% lower. I don’t know if I need to calibrate this somewhere, or if it’s just due to hardware imprecision. And as I was turning on and off both radios to test the squelch problem, I saw that sometimes (quite rarely, 1 in every 15th or 20th time i turned off the radio), some vertical lines remained on the screen for 10 seconds or so.

I’ve also been trying to understand the code (and put into practice what I'm learning at univesity!), so I set everything up, compiled, and noticed that features like Monitor Mode, or the custom power settings for each channel are not there anymore. Did I miss something, or have you stopped updating the repo due to those people that were trying to sell the code on ebay (in which case, I understand it)?

Anyway, I’m truly impressed at the amount of effort that has been put into this code, congratulations to you and the rest of the developers for your work!

73 :)

VK3KYY
Posts: 3318
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Location: Melbourne, Australia
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Re: Squelch open when battery under 7.0 V in DM-1801, etc.

Post by VK3KYY » Wed Dec 16, 2020 10:00 pm

The squelch problem is because the DM-1801 audio amplifier control hardware does not function below 7V, so its impossible for the firmware to turn off the audio.

I don't know how the official firmware handles it, they may just shut down the whole radio when the battery voltage gets that low.

We should probably just do the same, as a single cell voltage of 3.5V is getting very close to the battery being flat.

Re: Latest sources

Sources are now only being released when the firmware is in a stable state, and its not currently stable.

You can still investigate that bug if you like, using the published source code. The operation of the hardware control of the GPIO line that controls the audio amplifier has not changed

EA5JAQ
Posts: 5
Joined: Thu Jul 16, 2020 6:08 am

Re: Squelch open when battery under 7.0 V in DM-1801, etc.

Post by EA5JAQ » Thu Dec 17, 2020 4:24 pm

Thank you. I'll have a look.

By the way, I think I may have found how to correct another bug. The function codeplugContactIndexByTGorPC in source/functions/codeplug.c (lines 580-593) returns 0 if the contact is not found, but also when the contact is found and it's the first in the list (its index number is 0). This results in the first contact in the codeplug list not showing in the QSO display screen (instead it just shows TG and the number, as if it wasn't saved as a contact). If I may, I would recommend returning a -1 instead of a 0, and also correcting source/user_interface/uiUtilities.c, lines 931, 1887 and 1899, where the return value is required. That seems to have solved the problem for me, I don't know if I'm missing something and creating another problem somewhere else. Hope that helps :)

73

VK3KYY
Posts: 3318
Joined: Sat Nov 16, 2019 3:25 am
Location: Melbourne, Australia
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Re: Squelch open when battery under 7.0 V in DM-1801, etc.

Post by VK3KYY » Fri Dec 18, 2020 10:29 am

Can you tell me under what conditions you think it still finding the wrong contact, when using the last published Beta from 2020/11/12

Some bugs have already been fixed in this area, but perhaps not all

EA5JAQ
Posts: 5
Joined: Thu Jul 16, 2020 6:08 am

Re: Squelch open when battery under 7.0 V in DM-1801, etc.

Post by EA5JAQ » Sat Dec 19, 2020 9:42 am

You're right, it has already been fixed in the lastest development and release versions, sorry!

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