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ESP32-S31

espressif.com

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Re: ESP32-S31

#171

Post by imtringued »

topspin wrote: post #66
BenjiWiebe wrote: post #57

Earlier quoted context omitted.

Also why do you need 1uS for motor control? 1uS is 0.1 degrees of rotation at 16,666 RPM if I did the math right. I don't know much about motor control, is it normal to need that fast of feedback?

Field-oriented Control schemes modulate phase currents at high frequency; the feedback loop must be much faster than the motor phases. Until fairly recently, this stuff was the exclusive province of dedicated ICs (Trinamic et al.) and FPGA. Today, FoC can be done in (mostly) software with MCUs. Fast feedback loops are also necessary in SMPS, another area where precision, low latency MCU peripherals and software are a…

But even if you update your PWM signal on every PWM cycle, you won't go much beyond 30kHz. At some point you're running into high switching losses on your MOSFETs.

Re: ESP32-S31

#172

Post by NekkoDroid »

snvzz wrote: post #128
NekkoDroid wrote: post #51

Earlier quoted context omitted.

I see you are unfamiliar with `rv64mafdcbvh_zicsr_zicntr_zihpm_ziccif_ziccrse_ziccrse_ziccamoa_zicclsm_za64rs_zihintpause_zic64b_zicbom_zicbop_zicboz_zfhmin_zkt_zihintntl_zicond_zimop_zcmop_zcb_zfa_zawrs_supm_svade_ssccptr_sstvecd_sstvala_sscounterenw_svpbmt_svinval_svnapot_sstc_sscofpmf_ssnpm_ssu64xl_sstateen_shcounterenw_shvstvala_shtvala_shvstvecd_shvsatpa_shgatpa` also known as `RVA23`

rva23 is pretty friendly. Needn't use the long thing.

Yea, but remove any one of the extensions and you have a distinct arch with a name that is basically just as confusing.

The point I wanted to make is that nowadays a lot of the extensions do not have such a nice (semi) easy to remember name.

Re: ESP32-S31

#173

Post by jon-wood »

adamfeldman wrote: post #106
jon-wood wrote: post #56

Earlier quoted context omitted.

I think Z-Wave is a bit more open now but everything I’m seeing indicates Zigbee has pretty thoroughly killed it by not requiring arduous certification processes and being generally easier to work with. Z-Wave is technically superior with the ability to have devices directly communicate with each other for basic functionality but at least for me that wasn’t worth the massive markup and I’m slowly replacing anything z…

Zigbee supports binding, allowing devices to directly control each other without the intervention of a controller. For example, I've Inovelli light switches that communicate directly with Zigbee smart bulbs.

Oh neat, I'd not seen that exposed in the UI of anything I'm using with Zigbee so had assumed it wasn't a thing.

Re: ESP32-S31

#174

Post by tetris11 »

LeifCarrotson wrote: post #41
tetris11 wrote: post #22

Earlier quoted context omitted.

How does wired internet technically work on these chips? Is it just 8 dedicated GPIO pins?

Not "just", it's (presumably) 8 dedicated pins that form an RMII interface. This is not the same 8 pins as you'll find in your 4-pair Ethernet cable, it's a separate protocol which can be connected to an Ethernet PHY transciever like a TI DP83867E [1], which is further connected to "magnetics" [2], a convenient package of 8 integrated transformers and chokes that provide the galvanic isolation feature of an Ethernet…

Oh it's an ADC of some type. GPIO takes 0 or 3.3/5V at low frequencies, ethernet signals are a continuous range of 0 to 2V at high frequencies. Fundamentally incompatible without the PHY+magnetics

Re: ESP32-S31

#175

Post by wolvoleo »

ssl-3 wrote: post #142
wolvoleo wrote: post #82

Earlier quoted context omitted.

I do a lot of LED projects too but I just use ws2812s. What do you need the controller for? Large brightness perhaps? Just curious.

There's lots of ways to drive LEDs. WS2812 with any ESP32 board is one way, and that's a perfectly fine way; individual addressable LEDs sure are neat as hell. Amazing stuff can be done with them. And as you already know, a Chinese ESP32 dev kit costing $2 is enough to do ~all the things with this on the controller side. :) But there's other ways, too. At perhaps its simplest: Maybe RGB isn't your bag, and you just w…

I know how WS2812's work :) Like I said I use them.

My question was why use bare LEDs with a separate PWM controller like QuinnLED instead of WS2812. But yes size could be an issue. Long strings of WS2812 tend to get slow and if they all need to do the same thing at the same time it's ok.

Re: ESP32-S31

#176

Post by jamesmunns »

kelnos wrote: post #159
nine_k wrote: post #148

Earlier quoted context omitted.

I suppose ESP32-based modules usually carry networking and USB hardware which is immediately usable, without esoteric IP licenses, don't they?

The wifi bits are closed-source blobs. The rust embedded community has reverse-engineered some of it for some chips, but not sure how complete that work is.

It's worth noting that the support for ESP32 in Rust is official [0], and there are multiple full time engineers at Espressif working on developing and maintaining it.

[0]: https://github.com/esp-rs/esp-hal/

Re: ESP32-S31

#177

Post by superloika »

system2 wrote: post #68

I wish Espressif was an American company and publicly traded. I'd invest heavily. I have nothing but good things to say about their products. Their product naming could be better; S3 is going to show S31 in the search results.

Public companies only bring ruin.

Re: ESP32-S31

#178

Post by andylinpersonal »

tosh wrote: post #9
randomint64 wrote: post #3

Espressif is on fire! And the CPU even has SIMD instructions! RISC-V cores is a big deal for embedded systems because now compiling for SoCs is only a matter of `rustup target add riscv32imac-unknown-none-elf` instead of downloading half-broken proprietary toolchains and SDKs. Take a look at https://kerkour.com/introduction-to-embedded-development-wit... and https://kerkour.com/rust-esp32-pentest to get started with…

very interesting, do you have a pointer with more info on what kind of SIMD support it has?

The same as P4 rev 3.x, which is still undocumented. Assembler source and esp-nn/esp-dsp are your friend. Some people have also tried some stuff. And HP core 0 is scalar-only now.

Re: ESP32-S31

#179

Post by 9rx »

kelnos wrote: post #161
9rx wrote: post #90

Earlier quoted context omitted.

ESP-IDF is only compatible with the ESP32 range of devices, not all ESP-prefixed devices, so "ESP" alone is not sufficient information to satisfy the earlier comment.

Sure, but there's nothing in the name "ESP-IDF" that inherently means it can only support ESP32 devices. It could also support a new theoretical ESP33 device. (I don't have an issue with Espressif's ESP32-* naming scheme, but I don't think the ESP-IDF angle is a good argument for not changing it.)

Of course. There is no name that could inherently mean anything. Words are all made up and arbitrary.

Re: ESP32-S31

#180

Post by GeorgeTirebiter »

PowerElectronix wrote: post #108
BenjiWiebe wrote: post #57

Earlier quoted context omitted.

Also why do you need 1uS for motor control? 1uS is 0.1 degrees of rotation at 16,666 RPM if I did the math right. I don't know much about motor control, is it normal to need that fast of feedback?

The closed loop experiences a phase margin loss that is exponential with the frequency. At lower frecuencies it is negligible, but if you get close to the frequency of the delay the phase margin reduction becomes dramatic and the control goes from stable to unstable very fast. If the sensor has a limited bandwidth, you add the conversion delay and then the computation delay on top of that you end up with a max workab…

This is exactly correct. Low 10s of kHz is quite functional for machines moving in human space / speed.

If one is trying to do some assembly line (max # of operations per second), the power requirements alone get hard to manage. And then you're managing back EMF, eddy currents, heck, air resistance!

My rule: have dedicated low-level hw provide smooth PID response, mostly on the P term; and have a higher-level control produce the setpoint. Faster response means less need to rely on I or D terms as much (just because delta-T is so relatively small).

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