BMI323 IMU
So I was just about to other a batch of new boards, when this message regarding BMI323 popped up…
Grrrrrrrr…
1 Like
I used 3 whole days on this part… I don’t see why this part is any different than BMI160. Same footprint, same anything…
2 Likes
Basically, I think the Assembly Instructions still are valid, although the layout of the board now is slightly different.
I would highly recommend that you use the Swiss Machine Headers which you can get on this ALI-link. If you use normal pin-headers, there are some external connections to the board that will be difficult, and JST difficulties, etc…
However by using Machine Headers, you don’t need JST connectors, because the machine headers are themselves connectors (see the last image of the board that I have posted). You only need JST for CAN and HALL.
You don’t need to add 12 Mosfets - 6 will be fine (there are pictures of this).
Forget about the mica insulation, etc. It’s only “additional” (which is also mentioned in the assembly instructions).
No, to the 5V of the LED source. I know it’s strange as the output signal is 3.3V.
This video on YouTube explains how Machine Headers can be used as connectors. They are awesome:
SO THE IMU WILL BE
So I decided to code yet another IMU interface for VESC. Luckily, the BMI270 API is much like the BMI323 API, so I don’t feel quite as much as an idiot wasting my time on stupid stuff.
However, I will not use the SPI interface, but stick to I2C, which I know will work.
As a last minute change, I added an option for using PB6 for external light. You can choose to use PB6 for “red LED” (fault led) or External Light. Default is RED LED.
Bonus Info: Ext Light has a 2k pull-up resistor to +5V, as specified by sat-be
I think the pullup to 5V is a hack instead of a 5V level shifter, as the LEDs work with 5V logic level.
Crossing my fingers that the Momentary Switch will work without flaws. It did so in simulations. Also it should be able to turn itself off on a timeout.
And the official name is back to what it always has been…
A FOCKING AWESOME VESC6
5 Likes
how did you get it through with the 3 designs?
Thanks Jens!!!
It went through the first time…
Don’t start arguing with them, just send it in again, and it seems the the person on the next shift doesn’t care.
4 Likes
Hello,
I have assembled one of these boards by hand, and I’ve noticed that the 4.7nF snubber capacitors are only 50v rated. Is it a mistake, or am I missing something?
Good observation, and thanks. I don’t think you’re missing anything… I have to say that the board has been tested for 84V, and I’m also running it at 84V myself.
For reference: The MP2 board uses same type of mosfet as FOC_KING, but does it without any snubbers needed. So either I fix the issue, which is a little tricky, or I completely remove the snubbers.
To fix the problem with snubbers:
JLCPCB only has 1 type of capacitor in their “basic” components list that might fit. But the value is only 1nF.
JLCPCB Part # C9196
Package 1206
Description: 2kV 1nF X7R ±10% 1206 Multilayer Ceramic Capacitors
It seems that there is no optimum capacitor value, it’s more like the capacitor should be in a range. Assuming that 1nF is in this range, I calculate the resistor to be around 10.84 ohms (±) in order to keep the damping effect as close to what it is now.
New boards with new IMU270 just arrived today… See if I can test a snubber update with some manual soldering.
Currently the resistor is 5 ohms.
Wow, I’m excited to test some of the new stuff.
2 Likes
IMU look nice. hopefully it works as well 
1 Like
haha the only thing I am missing right know is a backpack for the esp32-c3 (vesc express) 
other than that its a very nice VESC
best Markus
Yes, this is the only outstanding “issue”, which I have politely ignored. I use the
NRF51822 for bluetooth. Assuming that you can use foc_king for lights, what extra value would you get out of the Vesc Express?
And sorry for any potential ignorance here. I’m not familiar with Vesc Express.
(You might be able to connect the PC-version Vesc Tool to foc_king, but why isn’t that already possible through bluetooth? Or maybe it is - I don’t know?)
you can use wifi for the remote and simultaneously BT for the app and watch. GPS tracking and you have a view more digital outputs / inputs for other stuff . More LEDs. In other words its awesome . Also it automatically connects to your home network for updates and config.
Also vesc express can connect to bms over ble and sent data back to the vesc.
1 Like