Heatermeter on new small-footprint platform: HLK-RM04 (RT5350 based)

[Fredrik O]

It needs 1min15s for a firmware update, so the speed is reasonable. I've basically taken the gpio-bitbang code straight from avrdude 6.0.1 (the "linuxgpio" mode) and it is based on the sysfs interface.

Now when it is up and running, the HLK-RM04 seems to do the trick quite well although the road there has been a bit bumpy (to say the least!). All the needed functions are available via the exposed pins, the stability is close to "production grade" and the main drawback is that the process going from as delivered to the desired openwrt state is a bit tedious. First, the boot loader must be replaced (which is done from the original GUI) and then, via TFTP, the first openwrt/linkmeter firmware is loaded. After that, sysupgrade works fine.

The AR9331 certainly looks interesting! I believe, with the emerging internet-of-things hype, there will be a number of platforms similar to the HLK-RM04, the Vocore and the AR9331 on the market.

 

[Bryan Mayland]

Oof that's pretty rough compared to ~3 seconds with SPI. Still that's not prohibitively long and I'm really the only person who uploads 100 firmwares a day to the AVR. I may consider just using the avrdude package for OpenWrt instead of hmdude. The problem originally was that on the WRT54GL getting the timing right to get the chip to flash was really touchy and avrdude took 1-2 seconds before it would start up, so I wrote the slimmed down version withe the RESET prompts. Then when we moved to the Pi there was no support for linuxspi yet so I wrote that in too. Everything has sort of caught up now and the code is there that it might be time to just switch over.

One of the benefits of the GL.iNET is that you can flash a new image right from the web gui. I can also program an AVR to do serial commands to connect to wifi and use the sysupgrade command to grab my custom firmware and install it hands free. I'd like to avoid using TFTP just because it causes major headaches for folks who aren't network or computer savvy. I'll admit that none of these are quite as simple as flashing an SD card with Win32DiskImager.

I too think there will be more platforms coming out. I thought when the Pi came out we'd have 40 other options by now. We sort of do but people seem to be going in the direction of "Make it more powerful, dual core, 1GB of RAM, multiple ethernet ports, thunderbolt, SATA..." and not in the direction of making a $20 linux computer with 10 GPIOs, wifi, and some storage.