Building an IoT Notification Device from Scratch • Hacker News Board

Re: Building an IoT Notification Device from Scratch

#11

Post by hnuser123456 » Wed, Oct 01, 2025, 3:51 PM UTC

bertwagner wrote: post #9

auspiv wrote: post #6

Earlier quoted context omitted.

bro your images are giant. every load of the page is transferring 40ish MB. back_panel_back_render.png is 11.3 MB. replace those with smaller versions and click to link to the larger.. but I do see both cloudfront and cloudflare headers so not sure why these aren't being cached by them

Thanks for letting me know, I will have to fix this soon. This was the first post as part of a new blogging setup I'm using and clearly I'm missing some of my old processes (like image resizing).

They are photographic images saved as PNG, which is lossless and intended for digitally created images with large areas of pixels with the exact same value. Please use a format intended for photographic images. Splashflag.png is 4.5 MB, it's 10.5 MB as an uncompressed BMP file, but only 600 KB as a JPEG with indistinguishable quality loss.

Re: Building an IoT Notification Device from Scratch

#12

Post by mlhpdx » Wed, Oct 01, 2025, 5:15 PM UTC

If you want to avoid “long polling” then MQTT isn’t the answer (it’s still a long held TCP connection waiting for messages). UDP would be the way to go, and with WireGuard as a carrier you don’t have to worry about NAT traversal issues (and get privacy as a bonus).

Love the project - would have been great when my kiddos were that age.

Re: Building an IoT Notification Device from Scratch

#13

Post by bertwagner » Wed, Oct 01, 2025, 5:31 PM UTC

mlhpdx wrote: post #12

If you want to avoid “long polling” then MQTT isn’t the answer (it’s still a long held TCP connection waiting for messages). UDP would be the way to go, and with WireGuard as a carrier you don’t have to worry about NAT traversal issues (and get privacy as a bonus). Love the project - would have been great when my kiddos were that age.

Thank you and I'm glad you enjoy the project. I'll have to look more into UDP for this type of solution.

Re: Building an IoT Notification Device from Scratch

#14

Post by mlhpdx » Wed, Oct 01, 2025, 5:42 PM UTC

Havoc wrote: post #8

The entire ESP ecosystem is quite accessible for people of modest technical ability. HomeAssistant+ ESPHome + ESP32 in particular is a good stack because it takes away most of the complexity. Common sensors have ESPHome code available with a quick google so just need to connect the wires right basically

Indeed about ESP32 being approachable. I particularly enjoyed finding and messing about with the Cheap Yellow Display. It’s a fun little platform and with LVGL making it pretty is a joy.

Would have been a nicer fit (smaller bevel) than the LCD in this project at about the same cost.

Re: Building an IoT Notification Device from Scratch

#15

Post by petesoper » Wed, Oct 01, 2025, 7:01 PM UTC

When I got to auto[ssid, etc in main.c it became clear the sophistication/excursion from the typical Esp32 code centerline is at many levels. Thanks for sharing!

Re: Building an IoT Notification Device from Scratch

#16

Post by NoiseBert69 » Wed, Oct 01, 2025, 7:18 PM UTC

Havoc wrote: post #8

The entire ESP ecosystem is quite accessible for people of modest technical ability. HomeAssistant+ ESPHome + ESP32 in particular is a good stack because it takes away most of the complexity. Common sensors have ESPHome code available with a quick google so just need to connect the wires right basically

Problem is that ESP32s are super power hungry once you start using BLE or Wifi.

For BLE you can use STM32s and Nordics. But Wifi-on-Chip is ESP32-only.

Re: Building an IoT Notification Device from Scratch

#17

Post by aksss » Wed, Oct 01, 2025, 7:26 PM UTC

NoiseBert69 wrote: post #16

Havoc wrote: post #8

The entire ESP ecosystem is quite accessible for people of modest technical ability. HomeAssistant+ ESPHome + ESP32 in particular is a good stack because it takes away most of the complexity. Common sensors have ESPHome code available with a quick google so just need to connect the wires right basically

Problem is that ESP32s are super power hungry once you start using BLE or Wifi. For BLE you can use STM32s and Nordics. But Wifi-on-Chip is ESP32-only.

BLE and WiFi are power hungry on any platform. LoRaWAN or zigbee are better for low power, low bw comms. Kinda sacrifice simplicity & ubiquity of support in that you need a gateway/router of some sort, but they are solid solutions with long range and high penetration.

Re: Building an IoT Notification Device from Scratch

#18

Post by 9029 » Thu, Oct 02, 2025, 11:09 AM UTC

Very cool project, I feel inspired to try something like this myself!

I noticed there seems to be a use-after-return with the creds returned from CredentialManager::retrieveCredentials (C-arrays can't be passed/returned by value). One solution could be to return Arduino Strings instead

Re: Building an IoT Notification Device from Scratch

#19

Post by jkscm » Fri, Oct 03, 2025, 3:42 PM UTC

mlhpdx wrote: post #12

If you want to avoid “long polling” then MQTT isn’t the answer (it’s still a long held TCP connection waiting for messages). UDP would be the way to go, and with WireGuard as a carrier you don’t have to worry about NAT traversal issues (and get privacy as a bonus). Love the project - would have been great when my kiddos were that age.

MQTT is not the same as long polling