OpenGD77

Hi guys,

first of all a big thanks to who is writing and maintaining this wonderful firmware.

I would submit a small flaw I met with last release.

Radio Model: DM1801
Firmware version: R2021071101
Battery charge: More than 7.2V
Voice: L1
Mode: FM Rx

Issue: Sometimes, with no reason, the low battery voice triggers.

I never noticed/had this with previous releases.

I also noted that Backlight function and Channel Details function share the same S1 switch. If you set backlight on manual the two functions collide.

Ciao

Nat

Hi,

Nat wrote: ↑

Sat Jul 17, 2021 6:55 pm

Hi guys,

first of all a big thanks to who is writing and maintaining this wonderful firmware.

I would submit a small flaw I met with last release.

Radio Model: DM1801
Firmware version: R2021071101
Battery charge: More than 7.2V
Voice: L1
Mode: FM Rx

Issue: Sometimes, with no reason, the low battery voice triggers.

I never noticed/had this with previous releases.

What is the voltage reported by the FW ?

Nat wrote: ↑

Sat Jul 17, 2021 6:55 pm

I also noted that Backlight function and Channel Details function share the same S1 switch. If you set backlight on manual the two functions collide.

Ciao

Nat

We can't do anything about this, we can't dedicate a key for the manual backlight, it shares the channel details key (plus, it doesn't impact each other).


Cheers.
---
Daniel

Also, did you changed the battery calibration value in the "Options" ?

Hi Daniel,

first time I saw the problem the voltage reported by firmware was 7.4V.
Yes, I corrected the voltage calibration adding 0.2V in order to get the correct voltage reading.

Now my reported battery voltage is 6.9V and, beside the voice problem, I can see the displayed value flashing from time to time.

This two issues never appened with last beta release.

P.S. For S1 switch no problem, I never use the manual backlight.

Cheers

Nat

Hi Nat,

Nat wrote: ↑

Sat Jul 17, 2021 10:08 pm

Hi Daniel,

first time I saw the problem the voltage reported by firmware was 7.4V.
Yes, I corrected the voltage calibration adding 0.2V in order to get the correct voltage reading.

Now my reported battery voltage is 6.9V and, beside the voice problem, I can see the displayed value flashing from time to time.

This two issues never appened with last beta release.

P.S. For S1 switch no problem, I never use the manual backlight.

Cheers

Nat

The low battery status starts when the voltage is below 6.8V, but the voltage is oscillating by few millivolts all the time.
Also, the battery voltage sensing is non linear, and to protect the battery, if you add 0.2V, the low battery threshold is raised by 0.2V too, so 7.0V in you case.
The low battery voice prompt or beep is played each 5 minutes, once this threshold is reached.
Finally, when the battery voltage is below a firm 6.2V (+ battery offset), and this for 10 seconds, the handheld will display the "Low Battery" message, and make itself not usable anymore.

The only things that changed in the latest release are, the battery calibration value is taken in account, and the 10 seconds at < 6.2V before stopping the firmware.

Maybe I will add some code to prevent low battery voice/beep (< 6.8V) triggering, to prevent battery voltage reading glitches.

Cheers.
---
Daniel

Hi Daniel,

I understand.

Nice idea to add code to prevent glitches reading.
But, as the low battery signal is a little bit annoing, maybe the starting point of Low Battery message could be set a little lower. Let say 6.6 vs 6.8.

Anyway do what you think is best.

Thanks again.

Ciao.

Nat

Daniel,

I haven’t had chance to check the code but your description seems the wrong way of doing things.

If someone calibrates his battery display to read accurate battery voltage it should not also change the thresholds. The thresholds should remain fixed at the original values. Otherwise by adjusting the battery calibration you are effectively reducing the available battery capacity.

6.2V and 6.8V are already quite high values for indicating a low battery, there is no benefit in increasing them.

Colin.

Colin,

The problem.is the accuracy of the voltage reading. If a positive offset is applied (to display, lets say,, 100% at full charge), checking against low and critical values will be wrong, from real battery voltage point of view.

Example:
Real battery voltage 6.8V
Applied offset +0.2V
Reported voltage 7.0V

But critical (shutdown) is < 6.2V, then.if you.don't apply the reading offset to the threshold values, it will be < 6.0V, at the battery tabs.


About the low and critical values, I don't trust about battery protections in any Chinese battery cell, so I think it's better to be overprotecting than make it catching.fire.

Am I wrong here ?



Cheers
---
Daniel

If someone deliberately uses the calibration to make the battery voltage read higher than it should do then I agree with your logic. But you are then trying to compensate for someone using the feature incorrectly at the expense of ruining it for those using it correctly.

Surely the point of battery calibration is to get the correct battery voltage reading. In that case it makes no sense to also adjust the thresholds.

I want my radio to turn off when the battery is really at 6.2V so I use the calibrate feature to make sure the displayed voltage is correct.

Colin.

Hi you both,

if this can be useful;
my radio stopped just now showing the low battery message.
Measuring the voltage across the battery terminals on the back I read 6.433V with radio on.

Ciao.

Nat