11000 réponses à ce sujet

[garfield2142]

Turns out I was a dummy and I didn't check that... It's weird that it was at 3.0V, because it was on the charger literally all night, so I didn't bother checking it with a multimeter.

[firened]

Hm i thought this UPS wasn't supposed to bootloop in an empty battery situation

[garfield2142]

Alright, I charged it to 3.8V according to my multimeter, time to revert sys.json back to see if ina219 comes back
Yup, it came back. I could've saved myself a few hours if I just checked the battery voltage first
But at least I found out that the UPS will still allow the pi to boot halfway through, even if there is not enough charge to finish booting.
It was just really strange that it always failed at the exact same part. Maybe that's when something really demanding would've happened, increasing current, and that's when the step-up gave up.

[firened]

Your theory makes sense yeah

[Mike118]

It was on the charger all night ? With the vigiboard ups ?

[garfield2142]

Yes. I'm testing several chargers and some of them cannot provide enough charge to keep the robot alive. I can still see a tiny bit of current through the ina219 and some stay in the red even while charging. I'm gonna remove the bridge across the ina219 now. I suspect the cheap cable I'm using to connect to the front

I might not even need this tumor anymore, I think there's plenty of room to mount the on/off switch and the magnet should stick out enough

[Mike118]

There are dedicated pins on the ups board to plug an external switch if wanted

[garfield2142]

Yes, I'm using the on/off pin. I just tried every single charger that I have, and none of them will charge enough to keep the robot alive while it's on, according to the ina219. Sometimes I can see +0.5A for 3 seconds, but it's back to -0.8A. When it's not "charging", it's around -1.2A --- -1.5A, so " some" charge is getting through
Tried all sorts of cables, both magnetic and "normal" usb C cables.
So this explains why my battery was empty by the morning.
Using the built-in USB-C port, with a 67W charger (setUSB bridges are not set), I get -0.7A (discharging)
It just literally crashed the client again with the 67W charger, now I don't have ina219 again

1754855461497_garfield2144_Panther.mp4   1,13 Mo

[Mike118]

When you don't have ina it won't crash the client with you 67w charger right ?

[garfield2142]

It crashed with a 5.3v 2.0A samsung charger too
Something is seriously wrong with that ina219
Are you available tomorrow for live testing? I can show you what happens with every single charger, just let me know in advance, as I literally can't keep the robot alive

[firened]

The BQ25792RQMR looks really cool!

@Mike118 I wonder if it could be `9.3.8.2 Dynamic Power Management` (DPM) page 37 https://www.ti.com/l...s=1754879865898

I couldn't find any info on how to test for it or change its behavior

[garfield2142]

I'll get one of these to analyze what happens with the USB while charging. It even has a graph https://www.aliexpre...rch|query_from:

[arkansar]

help the screen vidoe in my drone is black

[arkansar]

@Mike118 c'est posible avec un dji phamtom 2 vision+ de mettre un kit fpv ?

[Mike118]

Je n'ai pas essayé je ne connais pas le drone en question. Est ce qu'il a un mode " atterrissage automatique " en cas de perte de connexion avec la télécommande ?

[arkansar]

oui c'est ca

[firened]

@Garfield2142 I only have this, but it's for bullseye.
I think you tried this before a while ago

[firened]

@HyperS thanks for the pictures. Let's talk here

Nice parts

10) can you explain what you mean, that you have 3x Li-Ion 7.4V Batteries? 18650 cells? How many single cells?

1) doesn't your RC Car already have an ESC included? Perhaps you don't have to buy a new one.

6A) The picture shows a 4S battery holder. But you'll need a 2S.
6B) what is the amperage or wattage of the motor? Some RC Car motors are very powerful and will be too much for the 18650 holders. I wouldn't go above 5A rms and 10-20 A peaks with those holders.

5) The 2x max17043 i bought from AliExpress did not work, they are counterfeit and don't work with raspberry pi. Unfortunately the original (not from AliExpress) is expensive: 10$.
5A) if you want one, "DFRobot Gravity I2C 3.7V Fuel Gauge" is available, but it's 12$.
5B) they are also single cell only. ((you can't connect it to the first Li-ion cell, because this would bridge the BMS, which switches the battery negative)). You'll need to create a voltage divider, for that you'll need e.g. 2x 100 kOhm resistors.

11) do you have some more cables at home? You'll need some awg 16 or 14 for the bms, charger and switch.

Hope that helps

[firened]

1)
2)
3)
4) to measure the voltage you need a fuel gauge. But most fuel gauges only accept 1S voltage. Since you have 2S, you have to half the voltage. You're correct, it's probably not 2x 100 kOhm, because the fuel gauge might have a resistor on it as well. Values will depend on fuel gauge board.

5)
6) might work, would be good to check anyway.
Hm the WPL C24 looks like it's small. Yeah there will be a lot of added weight. I'm not sure if it will work with this car.

[firened]

@HyperS the WPL B24 could work. It has a combined receiver+ESC board, so you will need your own ESC. But you can get a smaller cheaper ESC like this 5A version
https://aliexpress.r...8085017227.html
Yeah 18650 from AliExpress is risky.
I buy them from a local swiss store.
Up to you
You'll be able to use it for other larger motors as well, so can make sense.

Both should work fine. The WPL B24 has a "180" type motor, which is listed as compatible on the 5A ESC specifications