Vesc Uart stopped working

So basically the uart on my vesc just stopped working Everything else works perfectly but I can’t use uart anymore with my Bluetooth module (with any app) nor with an arduino, it just doesn’t work The vesc looks fine, every component seems to be in place The weird thing is that it has been working intermittently for a couple of days but now it doesn’t work anymore at all I’ve triple checked connections… Has anyone got an idea about what could be the issue, has anyone already experienced that?

Check the baudrate of the UART, it might have done a reboot.

I think it should be at 115200.

My baudrate is at 9600 but Im sure that’s how it’s always been and I’m pretty sure that’s how it should be in order to use with my Bluetooth module I’ll try 115200 anyways

I thought 9600 is the default when it resets, Where did you buy the bluetooth thing and what baudrate did they tell you to put it on?

My module is a standard hm-10 But I’ve also been using the uart of my vesc with an arduino in order to retrieve informations such as voltage, or speed And the vesc doesn’t respond to my arduino anymore (I’m using 9600 baudrate for this) Is the uart hardware of my vesc damaged?

Are you clicking “Read Default Config” on the UART Baudrate tab? btw, where did you buy the bluetooth? By default they are 9600, if you bought it from the swedish guy it is 115200.

With the arduino you need to have the same baudrate as the vesc, like if its 9600 on vesc you need to set Serial.begin(9600);

And to retrieve information from the vesc you need to have if (VescUartGetValue(VescMeasuredValues)) { }

in the code.

My module is from China I know all of this and this is exactly what I’m doing in my code And all of this (bluetooth module and arduino code) was working a few days ago I’ve already reset my vesc to default configuration I think that it probably is an hardware problem on the vesc side…

Do you have selected it as UART in the App Configuration?

Yes I have ppm+uart selected

Does the red led from the hm-10 turns on when you turn on the board?

Yes, the problem is not about power its about the communication I can even connect to the Bluetooth module but it doesn’t display any data as it’s not communicating with the vesc

Make sure the connections are TX on the vesc yo RX on the module and viceversa, verify the connections with a multimeter.

Doble check the connection is ppm + UART, do that only on the master VESC, try 9600 on baud rate, delete all cached data on vesc monitor app on your phone.

Reboot the vesc and try again.

If the problem is still there, switch the master VESC to slave and viceversa, setup everything again on BLDC tool and try to connect.

If nothing still happens they your hm-10 needs to be replaced.

What version vesc firmware and the app? Did your app update? Baud has to be 9600. I ordered two units, one worked one didn’t. Initially the app worked straight away with the first release ackmaniac firmware, then updated the app, and it stopped working. Had to load the newer firmware and it’s working again.

I do have the last ackmaniac firmware version but thre problem is not about the Bluetooth module nor about ackmaniac app The problem is the vesc which doesn’t send data over uart (I have tested it with several Bluetooth modules which I know are working and with an arduino, all of these things where working normally a few days ago but stopped working eventhough I didn’t change anything)
I’m pretty sure the uart port of my vesc is somehow fried :/…

Have you checked for faults in the BLDC tool? Did it bring something up? Check with a multimeter if 3,3V and 5V are available on your uart port, otherwise it might have a defective resistor somehow. Make sure not to cause a short with your multimeter tips.

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Yes, it doesn’t report any faults 5v and 3.3v are available

Very weird… It has been working for like 5 minutes and now it doesn’t work again…

Hmm haven´t heard of that before… maybe @JohnnyMeduse can chim in here and has some ideas.

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The TX and RX pins go straight to the microcontroller (no other components in between that could blow, other than the trace itself). Have you tested continunity between the solder points and the pins on the microcontroller chip itself? RX is pin 29 and TX is pin 30 (count counter clockwise, starting where the white dot on the chip is). Here’s a few screenshots from the datasheet that should help find the pins (they’re rotated from each other, but you get the idea)

If that doesn’t do it, I think you may need something like a logic analyzer to really find this ghost. Its possible that you’re seeing 5v/3.3v when probing it with a multimeter, but that crumbles under load (thus indicating that the the converters may be dead)

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Thanks! I have already tried to check the continuity but I thought it was pins 14 and 15 I’ll try with 29 and 30 as you said I’m pretty sure the 5 and 3.3v are good because I could power a Bluetooth chip from there