What chips are inside the Arlec PCTH01HA smart plug?
The board hosts a BK7231N Wi-Fi SoC for control, a BL0937 metering IC for voltage/current/power, and a CHT8305 sensor for temperature and humidity [Elektroda, 359r, post #20371956]
Arlec PCTH01HA - Bunnings - CB3S BK7231N
TL;DR
- Arlec PCTH01HA Bunnings climate unit with power monitoring and temp/humidity was opened and flashed with OpenBK7231N firmware.
- The CB3S BK7231N board was wired directly to VCC, GND, RX, and TX, then programmed over UART using python3 uartprogram on a Raspberry Pi.
- Pin mapping identified P8 relay, P7 button_n, P6 LED, P9 SCL, P14 SDA, P26 BL0937 CF1, P24 BL0937 CF, and ADC3 BL0937SEL.
- Flash succeeded immediately, the unit booted an open access point, and MQTT works for relay control and BL0937 power readings; CHT8305 temperature and humidity remain unlinked.
Generated by the language model.
First post, hope this is useful, see topic here also as ByteMangler added some i2c info
https://github.com/openshwprojects/OpenBK7231T_App/issues/584
Unit is from Bunnings here in Aus, has power monitoring and temp/humidity, more on that later, first some pics:
https://grid-connect.com.au/smart-home-products/climate/
Seems to be welded shut mainly in corners, few bashes with rubber mallet (ok gentle whacks!) and spudger and case came open, no damage, just go easy is my input
Board and chips:
In terms of flashing, tried a few times with windows version before reading comments that for the N version, python is the better way.
Loaded up ras pi with spare sd card, raspbian lite installed and using python method, worked straight away. No desoldering any chips needed, just directly soldered jumpers to the chip vcc, gnd, rx and tx - all to cheap generic usb to serial dongle.
My command was this, renamed the downloaded firmware to file.bin for easier typing:
sudo python3 uartprogram /home/pi/file.bin --unprotect --startaddr 0x0 -d /dev/ttyUSB0 -w
That's it, bang straight away it came up with open access point, added wifi credentials, up and running in web ui, fantastic!
P8 Relay
P7 Button_n
P6 LED
P9 SCL
P14 SDA
P26 BL0937 CF1
P24 BL0937 CF
ADC3 BL0937SEL
Linked up to HA via mqtt and works great for relay and power readings from 937 chip.
Outstanding is only the i2c CHT8305 chip data to get linked up for temp/hum
See the above github link for more chatter or any posts after this.
Edit: The temp/hum sensor sits in a nice, somewhat isolated compartment so it might be useful!..
Hope this helps, thanks to the OpenBk team
https://github.com/openshwprojects/OpenBK7231T_App/issues/584
Unit is from Bunnings here in Aus, has power monitoring and temp/humidity, more on that later, first some pics:
https://grid-connect.com.au/smart-home-products/climate/
Seems to be welded shut mainly in corners, few bashes with rubber mallet (ok gentle whacks!) and spudger and case came open, no damage, just go easy is my input
Board and chips:
In terms of flashing, tried a few times with windows version before reading comments that for the N version, python is the better way.
Loaded up ras pi with spare sd card, raspbian lite installed and using python method, worked straight away. No desoldering any chips needed, just directly soldered jumpers to the chip vcc, gnd, rx and tx - all to cheap generic usb to serial dongle.
My command was this, renamed the downloaded firmware to file.bin for easier typing:
sudo python3 uartprogram /home/pi/file.bin --unprotect --startaddr 0x0 -d /dev/ttyUSB0 -w
That's it, bang straight away it came up with open access point, added wifi credentials, up and running in web ui, fantastic!
P8 Relay
P7 Button_n
P6 LED
P9 SCL
P14 SDA
P26 BL0937 CF1
P24 BL0937 CF
ADC3 BL0937SEL
Linked up to HA via mqtt and works great for relay and power readings from 937 chip.
Outstanding is only the i2c CHT8305 chip data to get linked up for temp/hum
See the above github link for more chatter or any posts after this.
Edit: The temp/hum sensor sits in a nice, somewhat isolated compartment so it might be useful!..
Hope this helps, thanks to the OpenBk team
Comments
Nice, I didn't even know there such kinds of devices. This is also interesting: BK7231 has two hardware I2C ports and they are already working in OpenBeken. I2C1 is P20/P21: https://obrazki.elektroda.pl/5898062000_1673043511_thumb.jpg... [Read more]
Awesome, thanks for the reply. The plug is currently monitoring the dishwasher, once it finishes, I'll unplug and double check the pins with meter. Will update this post in around an hour or so, cheers Edit... [Read more]
Thanks to our contributor, a simple CHT8305 driver has been added. USAGE: - select CLK pin - select data pin - save pins - for data pin, select two channels to store temperature and humidity (not... [Read more]
I found the information for this plug-in switch to be buried, so. This is the current working config i have running as of April 2023, on the latest release of OpenBK; 1.15.638 P6 - LED_n - 0 P7 -... [Read more]
Thank you, I will paste it into the online templates list, but please provide it in JSON format (copy template from Web Application) [Read more]
Complete Noob to this but (i'm assuming here) what do you need to add to the home assistant config to have the temp and humidity sensors show in home assistant? Currently have; mqtt: switch: ... [Read more]
Spent some time on this device and have found this mqtt config to display the temp and humidity sensors in home assistant, contained in this device. If you see any issues please let me know, I dont'... [Read more]
Hey @tonyb62 , I apologize for the slow reply. It's hard to check entire forum when I'm also working on OBK firmware and on our youtube videos: https://www.youtube.com/@elektrodacom Good job figuring... [Read more]
Yes I need to watch more of your youtube videos. I've found the yaml method doesn't stay in the Homeassistant tab and needs to be entered each time additionally, which is an issues when fiddling with... [Read more]
Do you mean the autogenerated YAML code in OBK? Well, it should just give you a quick start, not a final config. You should fiddle with code in Home Assistant configuration.yaml, which is kept as long... [Read more]
Yes, I was adding to yaml code in OBK, I see the error of my ways :) [Read more]
Hi, This is working beautifully, except that toggling the relay doesn't actually turn off the output. I can hear at least one relay click when toggling or unplugging while on, so I'm mystified about... [Read more]
Hello, are you able to open the case and inspect what's going on inside? From what I can see in the first post, this device is a rather uncommon model with not one, but two relays. [Read more]
User error, sorry - in future I won't rely on a low-power device behind a power adaptor with massive capacitors to check. Thanks for your great work on this project! [Read more]
Ah, I see.... they didn't discharge so you wrongly assumed that relay was still closed. Well, everyone makes mistakes. Let me know if you need help with anything else [Read more]