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Show HN: ESP32 RC Cars

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Re: Show HN: ESP32 RC Cars

#61

Post by IshKebab »

bri3d wrote: post #48
IshKebab wrote: post #44

Earlier quoted context omitted.

Right, but I don't see any reason why that must be the case. It's not a fundamental limitation.

To a great extent you trade statefulness (inter-frame compression, FEC, HARQ, sounding parameters, overhead) for efficiency, so improving link recoverability comes at a cost. There is an existing solution which makes this trade - HDZero. It works amazingly at close range in clean RF environments and has good analog-esque falloff characteristics, but in terms of absolute efficiency it is very bad and therefore does no…

> but in terms of absolute efficiency it is very bad

Worse than analogue?

Re: Show HN: ESP32 RC Cars

#62

Post by bri3d »

mkesper wrote: post #53
the__alchemist wrote: post #23

Earlier quoted context omitted.

I will add for those who haven't tried these, as it usually doesn't come across in verbal comparisons: Digital FPV (like DJI's system) looks vastly better than analog. I think the best comparison is: Digital looks like a modern movie, youtube video etc, and analog looks like CCTV footage from the 80s. I will also clarify on ELRS: It uses ESP32, but it is a thin wrapper around Semtech LoRa (~915Mhz and 2.4Ghz) SX128x…

I heard people flying analog also use quite a bit more transmitter power than allowed for non-regulated devices to keep things manageable. Do you have any reference what's possible with digital when staying in the allowed regime?

A big advantage with digital video in the US is that some systems, like DJI’s, have FCC approval and can go up to 1 or 2W EIRP legally, so the allowed regime is bigger (there are basically no FCC approved analog video systems, so really you need an amateur radio license and to operate under amateur radio rules for analog video in the US).

Re: Show HN: ESP32 RC Cars

#63

Post by idunnoman1222 »

05 wrote: post #51
idunnoman1222 wrote: post #31

A good 2.5 inch RC car is 30 bucks on AliExpress now, A standalone 5.8 GHz analog camera is 25 bucks. Just for those that may be more interested in the outcome than just a fun project to do

A standalone (you mean AIO) camera with a builtin VTX is generally even shittier than regular analog, and you still need analog goggles for it. For anyone who doesn’t need prescription glasses or wears contacts, DJI O4 ‘lite’ with the N3 goggles is a much better idea.

You don’t need goggles you can just get a receiver for your TV… or any screen.. also Qualify shittier do you mean the range of the antenna? A 2 1/2 inch car it does not go outside, so not relevant. If you mean the camera well buyer beware i guess the ones I got were fine. Also, I thought we were comparing this to a cheap ESP 32 build and not some top-of-the-line digital thing the SP 32 build is gonna have a terrible lag. You’re not actually gonna be able to race your friend with it… my setup is cheap and has low latency. no one is gonna buy top-of-the-line DJI crap to race a 2 inch car around their basement

Re: Show HN: ESP32 RC Cars

#64

Post by 123pie123 »

Lord_Zero wrote: post #39
123pie123 wrote: post #25

before you get a ESP32 CAM (I love em) consider one with an external antenna it may be wise to read this https://www.reddit.com/r/esp32/comments/r7kqtt/esp32cam_supe... I got fairly bad frame rate until I tried some of the advise

Can you recommend an exact model?

I'm afriad not, I bought a load of esp32 cams with out the external antenna - hit a problem with the frame rate and fixed it from the advice from the link

for my other projects I did use a ESP32 with an external antenna, but they did not have a camera port

These things are so cheap just buy one and see (unless time is an issue)

edit: the OP did add this link to one https://www.aliexpress.com/item/1005001468076374.html - note this does not have a usb connector - you can get them separately

Re: Show HN: ESP32 RC Cars

#65

Post by 05 »

idunnoman1222 wrote: post #63
05 wrote: post #51

Earlier quoted context omitted.

A standalone (you mean AIO) camera with a builtin VTX is generally even shittier than regular analog, and you still need analog goggles for it. For anyone who doesn’t need prescription glasses or wears contacts, DJI O4 ‘lite’ with the N3 goggles is a much better idea.

You don’t need goggles you can just get a receiver for your TV… or any screen.. also Qualify shittier do you mean the range of the antenna? A 2 1/2 inch car it does not go outside, so not relevant. If you mean the camera well buyer beware i guess the ones I got were fine. Also, I thought we were comparing this to a cheap ESP 32 build and not some top-of-the-line digital thing the SP 32 build is gonna have a terrible…

Top of the line would be Goggles 3, N3 is the budget line and it costs less than analog goggles. Maybe with cars it's different, but nobody flies with a screen - the immersion just isn't there..

Re: Show HN: ESP32 RC Cars

#66

Post by t0mas88 »

eurekin wrote: post #56
t0mas88 wrote: post #5

Cool! I've made an ESP32 powered RC tank on tracks, controlled with a PlayStation 4 controller over Bluetooth. The basic software is very easy to start with, about 20 lines of C using a library for the Bluetooth controller. From there I've added features for easier control. Using two sticks for two tracks works at low speed, but the thing goes close to 20 km/h (I've used two drone motors for it) so then you need a di…

Very impressive! I've never looked into RC builds before - how are they controlled? Do you connect the PS4 controller directly to the esp?

Yes, the ESP32 has Bluetooth support and there is an open source library to read the inputs from a PS4 controller. So I just wrote a small program to connect to the controller and send the right commands to the motors.

I think "traditional" RC people use a separate receiver module that links to their remote instead of doing this in software.

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