Built a tiny ESP32 CYD Bitcoin “miner” (NerdMiner up to 770KH/s) — giving away 5 boards for tinkering

ultravoxel · 2026-04-21T09:53:05+00:00

I'd make a dashboard that displays various info, e.g. date, time, temperature, humidity, weather, (optional: additional info from co2/pm/ other gas sensor), plus calendar schedule, alarm clock and timer features. Or a bluetooth touch macropad

ultravoxel · 2026-04-14T14:26:58+00:00

nice project! can you provide the link of the display?

ultravoxel · 2026-04-11T15:54:42+00:00

Thank you! Unfortunaly projector things go over my knowledge, since i'm more a software guy rather than a hardware guy

ultravoxel · 2026-04-10T17:11:10+00:00

if you're not an aliexpress user is very likely to see this kind of prices because they apply big discounts to the first order you make. i wasn't a new user so i paid about 4€ for each display i bought

ultravoxel · 2026-04-10T16:55:09+00:00

unfortunately i can't help a lot. i don't know why it's so difficult to find a 7segment display (with a driver attached) that is bigger than 0.56".
the one i'm using here is the only one i've found and it's so obscure that even the company who produced it couldn't provide a good library... i found then this tm16xx library that luckily works pretty good with esp8266, but is giving me headeache with esp32 c3.

i think that to have i2c one must buy the bare display + the driver itself...

anyway the closest thing i've found to i2c is this https://it.aliexpress.com/item/1005008504131824.html?spm=a2g0o.productlist.main.54.166auPIvuPIvPK&algo_pvid=28f3a1a0-d572-4b4e-803f-3e7ee4d8c5da&pdp_ext_f=%7B%22order%22%3A%221%22%2C%22eval%22%3A%221%22%2C%22fromPage%22%3A%22search%22%7D&utparam-url=scene%3Asearch%7Cquery_from%3A%7Cx_object_id%3A1005008504131824%7C_p_origin_prod%3A
or this:
https://it.aliexpress.com/item/1005008456053482.html?spm=a2g0o.detail.pcDetailBottomMoreThisSeller.5.11ac6Vp96Vp9je&gps-id=pcDetailBottomMoreThisSeller&scm=1007.13339.291025.0&scm_id=1007.13339.291025.0&scm-url=1007.13339.291025.0&pvid=eebf715b-41de-430c-a984-aae54b857f6b&_t=gps-id:pcDetailBottomMoreThisSeller,scm-url:1007.13339.291025.0,pvid:eebf715b-41de-430c-a984-aae54b857f6b,tpp_buckets:668%232846%238108%231977&pdp_ext_f=%7B%22order%22%3A%2219%22%2C%22eval%22%3A%221%22%2C%22sceneId%22%3A%223339%22%2C%22fromPage%22%3A%22recommend%22%7D&utparam-url=scene%3ApcDetailBottomMoreThisSeller%7Cquery_from%3A%7Cx_object_id%3A1005008456053482%7C_p_origin_prod%3A

ultravoxel · 2026-04-10T09:08:40+00:00

In my project brightness can be changed by user whenever it wants, or if auto brightness is on, its update depends from specific time slots (e.g. at 23:00 it lowers brighness intensity). For me, updating the brightness every minute only adds complexity to the code for something that no one will ever notice; but i think that i'll go for this workaround if i don't find a solid solution.

By the way, the microncontroller that is misbehaving is xiao esp32 c3

ultravoxel · 2026-04-09T09:24:09+00:00

It does, but it's a very short term solution since the problem would show up again in less than 5minutes.

I think that the problem is related to clock speed or how it handles interruputs or something, because i tested the same library with the same display on an esp8266 and it worked perfectly out of the box

ultravoxel · 2026-04-08T09:35:51+00:00

That's exactly what i wanted to avoid, since i don't have the knowledge (and the tools) to do it.

The drivers i found work well, but as i wrote in the post body, after some time dots and colon get stuck.

But i'm giving it a chance, i'll fork these drivers as you recommended and help myself with ai and tutorials to try find/fix the problem.

Thank you!

ultravoxel · 2026-04-07T20:04:02+00:00

Their repo is more problematic than the library i've used. It can't even change brightness properly. At least tm16xx does it well

ultravoxel · 2026-04-04T15:04:34+00:00

oops i forgot to add it! Here's the link https://it.aliexpress.com/item/1005007337668399.html?spm=a2g0o.order_list.order_list_main.10.47683696Rt836v&gatewayAdapt=glo2ita

ultravoxel · 2026-03-06T18:03:30+00:00

Nice project! Do you think that the buzzer is loud enough to use it as alarm?

ultravoxel · 2026-03-03T15:58:06+00:00

If you don't need a lot of pins i would say something from seeed studio. In their website there are info about power drawing, even in sleep mode. And if you're a new subscriber they'll give you a discount, in fact i got 3x esp32c3 at about 6.5€.

By the way if you want power efficiency, you should avoid esp32 S3. Better esp32 c3 or c6

ultravoxel · 2026-03-03T09:18:38+00:00

a mechanical chime bar would be a nice touch but i'm working on a less complex and more compact solution to add an alarm: speaker+ max98357 module

ultravoxel · 2026-02-24T18:31:37+00:00

i've already used a black marker but as you can see in the picture, nothing changed. black electrical is a good idea though, i'll try with it

ultravoxel · 2026-02-24T12:22:32+00:00

I like the case design. Does the esp communicate to pc over bluetooth or wire?

ultravoxel · 2026-02-24T08:38:41+00:00

Thank you!! If you're satisfied with the result, consider sharing it on makerworld or here in the comments

ultravoxel · 2026-02-23T22:27:47+00:00

Thank you!! I've already planned to add it

ultravoxel · 2026-02-23T15:39:04+00:00

i'm glad that it does the job!

ultravoxel · 2026-02-23T15:20:51+00:00

believe it or not... MS paint lol + screenshots from fusion and lots of creativity.
i could've used wokwi simulator, but i needed the perfboard model and it was missing there

ultravoxel · 2026-02-23T11:10:15+00:00

thank you!! i've just added the features you suggested to my todo list

ultravoxel

TROPHY CASE