BLDC ESC bula design sanit check  - Page 1
Forum section: electronics / projects

author: Sniper1
author_rank: Regular Contributor
timestamp: August 01, 2023, 06:06:27 pm
content: So i am making a dual ESC and this is my V2 design.Can anyone take a look and do a quick check ?not sure how to post images/files so ill post the reddit link of a post of the same board.git link:https://github.com/immortal-sniper1/Programable_ESC_Projects/blob/master/ESP32_dual_ESC/schematic.pdfhttps://www.reddit.com/r/PrintedCircuitBoard/comments/15dht4k/review_request_double_bldc_esc/NOTE: YES I SEE THAT I MADE A TYPO

author: Benta
author_rank: Super Contributor
timestamp: August 01, 2023, 06:28:00 pm
content: What's a "bula design"?Also, your reddit link needs an account. No thanks.

author: Sniper1
author_rank: Regular Contributor
timestamp: August 01, 2023, 06:31:53 pm
content: typo.....it was supposed to be double designs as in 1 left 1 rightSince when does reddit need and account to read a post? ( tried in private window and it did work...)git link:https://github.com/immortal-sniper1/Programable_ESC_Projects/tree/master/ESP32_dual_ESChttps://github.com/immortal-sniper1/Programable_ESC_Projects/blob/master/ESP32_dual_ESC/schematic.pdf

author: tonyarkles
author_rank: Regular Contributor
timestamp: August 04, 2023, 02:57:17 pm
content: Do you have firmware partially developed for this already? I'm quite curious to know if you can adequately synchronize the timers on the ESP to get things spinning correctly; my limited experience with ESC software generally used hardware with timers that are dedicated to driving BLDC/PMSM motors (e.g. some of the STM32G parts). Schematic seems reasonable to me!Edit: Oh, one other thing that does jump out at me: I generally have seen low-side current sensing, not high-side. I don't have a good understanding of what the design tradeoffs are there, but it does jump out as something unusual in your design.

author: Sniper1
author_rank: Regular Contributor
timestamp: August 04, 2023, 07:43:40 pm
content: I ordered it but it did not arrive yet.As for the SW i didnt start yet but i did do research on how to PWM them properly and started some LTspice sims ( will ask for help in another post soon tm).Regarding those MCUs yes it was interrupts BUT the ESP32 can do that too and it is like an order of magnitude faster so i am sort of confident i can make it work well.Regarding current sensing:low side: simpler cheaper but can mess up with signals , you also have a odd ``GND``high side: more complex but no signal problems since GND is 1 thing not GND before shunt for x part of the circuitryIn my case thy also act as a thing that i can use to disable power to a block , for safer SW development .

author: tonyarkles
author_rank: Regular Contributor
timestamp: August 05, 2023, 01:40:30 pm
content: Awesome! Looking forward to seeing where this project goes! If you can squeeze good enough timing out of the ESP32 timers to get the motors going reliably, this could be a game changer for "smart ESCs".

author: Sniper1
author_rank: Regular Contributor
timestamp: August 06, 2023, 06:29:55 pm
content: I am not sure how this is a game changer besides that it would prove you dont need a STM32. With some optimization on the pins i think i can use 1 ESP32 for 3 BLDs more then that would be very hard if not impossible since there are not that many pins , maybe if i went with the chip itself and not the module....... then again if i used some muxes maybe......For me atm the main problem is figuring out a target main switching frequency and target PWM frequencyi have a few BLDS they are 7uH and 50mohm per port and i am trying to figure out those frequencies , ideally i want to keep the current under 20A ( since a 20A ESC was recommended)