@zboblamont Thanks. FWIW, I first became aware of the issue from reading CREE datasheets. At some point CREE put out an advisory: https://www.cree.com/led-components/media/documents/XLamp_EyeSafety.pdf
Cree classifies its own XR-E royal blue LED's as RG-3 High Risk, which it defines as "Hazardous even for momentary exposure".
"To date, the testing shows that Cree’s blue and royal blue LED components (450-485 nm dominant wavelengths) pose a higher potential eye safety hazard than its white LED components. Other colors of LED components, such as green and red LED components, do not pose as significant of an eye safety risk. Regardless of LED color, Cree advises users to not look directly at any operating LED component. "
In the context of this thread, it's that last sentence that's tricky. I suppose for an indicator common sense suggests it's just plain safer to stick with a lower power LED and run it for a longer duration. So, the challenge will be to find high lumens/watt but at not too high absolute lumens.
@rmh said in EV Charger (type 2) with RESTful API and Wifi recommendations?:
@รอเร-อ btw Normal single phase type 2 charging on an EV is 32a = 7 Kw. If your ev can charge at 22Kw, then it will need a 3 phase supply. OpenEVSE can do this but you will need to put a 3 phase contactor in it.
Thanks a lot. That seems to be exactly what I'm looking for. I didn't order the kit though. I ordered the EmonEVSE WiFi Connected EV Charging Station IEC 60947-5 (Type-2)
I'm very excited to get started. Ohh... I'll need an EV too... ha ha
@skywatch Agreed entirely on the supply quality for the Pi, but disagree with the "bonus" of throwing away the SD. Murphy's Law applies, a RO card allows you to revert to a spare OS card if the drive ever fails...
The Pi3 has 4xUSB2, the Pi4 uprated to 2xUSB2 + 2xUSB3, the data transfer limits of the Pi3 are lower, but still plenty fast.
PS - I recall some USB adapters for SSD could cause issues for the Pi, fairly sure it was on a video by the "Swiss guy"...
Today I finished to fix failed soldering (too old solder paste made a mess ) on the "motherboard" of my air quality sensor.
It's based on ESP32, uses a charging IC with power path so it can run on batteries for around a day or stay plugged without destroying the battery, step down from USB/battery to get VCC, storage on I2C EEPROM, flash and/or µSD card (depending on use case), one SK6812 mini RGB led as indicator, a small 240*240 IPS LCD (backlight driven directly by ESP32 pin in high drive capability mode), a 3 way switch for basic user interface + footprint for PAJ7620 gesture recognition module, accelerometer and I2C IO expander to manage the 3 way switch and interrupts from sensor modules.
Sensor modules will be added on top, connected using an FPC connector. At the moment I made only one sensor PCB able to manage usual PM, CO2 and formaldehyde sensors. Only one sensor per sensor board where an attiny841 manages the UART sensor and convert it to I2C, it also manages the 5V step up to power the sensor.
On the main board I also added an NRF24 footprint so with the same PCB I will be able to make a gateway with integrated battery backup.
I'm pretty happy with the relatively well aligned components (no, I don't have OCD ) , too bad I had to unsolder, clean and re-solder each component as it now looks botched up. But at least everything (except a missing connection on µSD card, hence the blue wire) is working,
LCD test showing jpgs from SD card
@Jens-Jensen Thanks for posting that video. I wonder if in Julien's' case there might have been moisture penetration through the insulated wiring ingress points. If the outer insulation coating were sufficient, then waterproof wiring wouldn't require that sticky goo they put underneath it. Once it gets inside the "sealed" enclosure by travelling through the insulation, it can do its damage with nothing to stop it. So....maybe if Julien had applied something like Corrosion X or some other conformal coating and then sealed it all up it might have lasted longer. I think extending the heatshrink to completely cover the wiring so that only the metal connection terminals on the end are exposed may be the only way to prevent the moisture ingress, assuming the heatshrink stuff really is moisture proof.
In contrast, I suppose in the Great Scott epoxy filled approach, even if moisture does ingress through the wiring insulation, it has nowhere to go since all the electronics are protected with the epoxy.
For those who don't know: something can be waterproof without being moisture proof. Housewrap would be a perfect example of that, as would gortex raincoats. So, having something that's waterproof rated doesn't tell you enough information. i.e. even something rated at ip68 could let in moisture. A lot of plastics are waterproof, but not moistureproof. Also, from what I've read, the most commonly used hot glues are not moistureproof.
And of course if you have any air at all inside, the moisture in it might condense into water if it gets cold enough.... So, I think Julien's setup is prone to eventual failure for a whole host of reasons in addition to those that he mentioned: the host glue, the wire insulation travel path, and the trapped air.
I did once try an experiment using just hot glue to seal cheap corrosion prone chinese electronics (pretty much engulfing it in hot glue as Julien tries at the end of his video), and I was surprised that it failed in just a month or two of wet outdoor weather.