When power is applied the H7 shows the white led for a second. Then flashes red 3 times.
What does it his indicate?
I don’t see how it could be a hardware failure yet.
I’ve been having way more anguish than I should.
The red led flashing it typically the uPY or SD card being accessed by the PC. It’s not a bad thing. The white LED flashing is the system finishing its boot up.
It won’t work for me like that.
So… I usually have unique problems with everything. Automotive , fabrication, electronics… etc.
Here’s my unique situation in this scenario.
The H7 works with a battery only if I use a USB to start it up (green light flash) . And then connect the battery. Then i can unplug the cable .
With a battery connected its just white then red flash 3 times and won’t work .if it even gets that far in the process with the battery.
Ah, sounds like a voltage sag then and undervoltage.
So, if you scope the 3.3V rail you will probably see a dip when the system is booting.
I can assure you though that the system does work with a battery if it’s strong enough.
It still doesn’t work right.
The battery has 3.97volts and needs a jumpstart via USB BEFORE the battery gets plugged in.
And I have to wiggle the USB for it to “catch” the data and send it. Powers ok sometimes. Just no data.
I shouldn’t have to add a capacitor ?
Yes, just the ones that say that they are connected.
As for the battery, do you have a oscilloscope? If so, you should be able to see a battery voltage dip.
I plugged the USB in today and it booted up first try.
Didn’t touch the device. Unplugged the rectangle, plugged it back in, and it didn’t boot up. Just a white blank LCD screen and no flashing.
Need to know why the issue is intermittent.
Even if tried connecting the USB(4.06volts) and the battery.
Weird, if I plug both battery and USB same time the VIN shows voltage .
With only 1 of the two connected I get no VIN voltage .
Something has to be seriously off with the device.
One time it said 4.06 . Another time it said 4.3 on both terminals.
BAT and VIN are connected to each other. They aren’t separate inputs.
Can you take a picture of the board - front and back? There are a lot of clone devices out there which are not ours and use refresh chips (chips removed from another product).
Is this the OpenMV board ? The board i recieve about 5months ago says 6/23/21
The lcd screen says 2/11/20
Looks official.
Yeah… so, the VIN design for this board isn’t super amazing. However, batteries can supply quite a bit of surge current.
So, if things work fine with just USB… but, fail with the battery then it’s because the battery can’t handle a large instantaneous current draw. You need a different battery then.
The 3.3pin is reading ng 4.08volts.
The VIN terminal is only reading .002 volts .
So youre telling me that they sent me super old , pretty sure faulty product, from 2020 even though i purchased it in 2023?
It doesn’t “work” when power is applied.
Its a random chance that it works. Like 1 in 50 or perhaps more.
It lights up the LCD , gets power at the 3.3pin, has good ground, but doesn’t function.
Wait… what? That would suggest the system is destroyed. The 3.3V pin is the output of the internal regulator. It should always be 3.3V.
…
Okay, let’s make this simple. Without the LCD screen attached, does the device work via USB? And then, does it work with a battery?
So youre telling me that they sent me super old , pretty sure faulty product, from 2020 even though i purchased it in 2023?
It defiantly was not faulty when we shipped it to you. Looking at the soldering job on the headers… I am concerned. The unit should have been supplied with two 1x8 female headers with long pin rows.
…
If you are located in the USA I can ship you another known working unit without issues from my personal inventory. We are just about sold out from our warehouse of the H7.
I am located in the u.s.
That would help me out so super much if replaced since ive had this issue from the beginning. I feel the need to say sorry about that .
When the LCD is removed, the voltage gets even higher like 4.8volts instead of 4.08volts.
And the VIN showing a thousandth of a volt .
But yeah, i would admire that so much if i could get a replacement board.
Email sent.
Im not sure which one to send from.
1 email pays. The other gets a receipt.
I got the email.